关于Spring MVC注解 @Transactional 事务标签 @InitBinder 标签
之前我们在AccountService中加入了注解@Transactional标签,但是要想要真正发挥事务作用,还需要一些配置。
主要需要调整dao.xml文件
dao.xml-事务管理
- <bean
- id="transactionManager"
- class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
- p:dataSource-ref="dataSource" />
- <tx:annotation-driven
- transaction-manager="transactionManager" />
- <bean
- id="transactionManager"
- class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
- p:dataSource-ref="dataSource" />
- <tx:annotation-driven
- transaction-manager="transactionManager" />
- <bean
- id="transactionManager"
- class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
- p:dataSource-ref="dataSource" />
- <tx:annotation-driven
- transaction-manager="transactionManager" />
细化一下AccountService接口方法
AccountService.java
- /**
- * 2010-1-23
- */
- package org.zlex.spring.service;
- import org.springframework.dao.DataAccessException;
- import org.springframework.transaction.annotation.Transactional;
- import org.zlex.spring.domain.Account;
- /**
- * 账户业务接口
- *
- * @author <a href="mailto:zlex.dongliang@gmail.com">梁栋</a>
- * @version 1.0
- * @since 1.0
- */
- public interface AccountService {
- /**
- * 获得账户
- *
- * @param username
- * @param password
- * @return
- */
- @Transactional(readOnly = true)
- Account read(String username, String password);
- /**
- * 获得账户
- *
- * @param id
- * @return
- */
- @Transactional(readOnly = true)
- Account read(int id);
- /**
- * 注册用户
- *
- * @param account
- * @return
- */
- @Transactional(readOnly = false, rollbackFor = DataAccessException.class)
- Account register(Account account);
- }
- /**
- * 2010-1-23
- */
- package org.zlex.spring.service;
- import org.springframework.dao.DataAccessException;
- import org.springframework.transaction.annotation.Transactional;
- import org.zlex.spring.domain.Account;
- /**
- * 账户业务接口
- *
- * @author <a href="mailto:zlex.dongliang@gmail.com">梁栋</a>
- * @version 1.0
- * @since 1.0
- */
- public interface AccountService {
- /**
- * 获得账户
- *
- * @param username
- * @param password
- * @return
- */
- @Transactional(readOnly = true)
- Account read(String username, String password);
- /**
- * 获得账户
- *
- * @param id
- * @return
- */
- @Transactional(readOnly = true)
- Account read(int id);
- /**
- * 注册用户
- *
- * @param account
- * @return
- */
- @Transactional(readOnly = false, rollbackFor = DataAccessException.class)
- Account register(Account account);
- }
- /**
- * 2010-1-23
- */
- package org.zlex.spring.service;
- import org.springframework.dao.DataAccessException;
- import org.springframework.transaction.annotation.Transactional;
- import org.zlex.spring.domain.Account;
- /**
- * 账户业务接口
- *
- * @author <a href="mailto:zlex.dongliang@gmail.com">梁栋</a>
- * @version 1.0
- * @since 1.0
- */
- public interface AccountService {
- /**
- * 获得账户
- *
- * @param username
- * @param password
- * @return
- */
- @Transactional(readOnly = true)
- Account read(String username, String password);
- /**
- * 获得账户
- *
- * @param id
- * @return
- */
- @Transactional(readOnly = true)
- Account read(int id);
- /**
- * 注册用户
- *
- * @param account
- * @return
- */
- @Transactional(readOnly = false, rollbackFor = DataAccessException.class)
- Account register(Account account);
- }
这里我把注解@Transactional调整到了具体的方法上,也就是说这样写的话,凡是加入注解的标注的方法都属于事务配置!
Account register(Account account);用做用户注册作用!
@Transactional(readOnly = true)只读属性
@Transactional(readOnly = false, rollbackFor = DataAccessException.class)只读关闭,遇到DataAccessException异常回滚!如果不对异常进行处理,该异常将一直向上层抛出,直至抛出到页面!
如果你的Eclipse集成了SpringIDE,你可以观察一下这时的xml配置文件和AccoutServiceImpl.java的变化!
这次,来个用户注册功能演示,故意在某个位置制造一个异常,看看是否正常回滚!
先看注册控制器
RegisterController.java
- /**
- * 2010-2-4
- */
- package org.zlex.spring.controller;
- import java.text.DateFormat;
- import java.text.SimpleDateFormat;
- import java.util.Date;
- import org.springframework.beans.factory.annotation.Autowired;
- import org.springframework.beans.propertyeditors.CustomDateEditor;
- import org.springframework.stereotype.Controller;
- import org.springframework.ui.ModelMap;
- import org.springframework.web.bind.WebDataBinder;
- import org.springframework.web.bind.annotation.InitBinder;
- import org.springframework.web.bind.annotation.ModelAttribute;
- import org.springframework.web.bind.annotation.RequestMapping;
- import org.springframework.web.bind.annotation.RequestMethod;
- import org.zlex.spring.domain.Account;
- import org.zlex.spring.service.AccountService;
- /**
- * 用户注册控制器
- *
- * @author <a href="mailto:zlex.dongliang@gmail.com">梁栋</a>
- * @version 1.0
- * @since 1.0
- */
- @Controller
- @RequestMapping(value = "/register.do")
- public class RegisterController {
- @Autowired
- private AccountService accountService;
- @InitBinder
- public void initBinder(WebDataBinder binder) {
- // 忽略字段绑定异常
- // binder.setIgnoreInvalidFields(true);
- DateFormat format = new SimpleDateFormat("yyyy-MM-dd");
- binder.registerCustomEditor(Date.class, "birthday",
- new CustomDateEditor(format, true));
- }
- @RequestMapping(method = RequestMethod.GET)
- public String initForm(ModelMap model) {
- Account account = new Account();
- model.addAttribute("account", account);
- // 直接跳转到登录页面
- return "account/register";
- }
- @RequestMapping(method = RequestMethod.POST)
- protected String submit(@ModelAttribute("account") Account account) {
- int id = accountService.register(account).getId();
- // 跳转到用户信息页面
- return "redirect:profile.do?id=" + id;
- }
- }
- /**
- * 2010-2-4
- */
- package org.zlex.spring.controller;
- import java.text.DateFormat;
- import java.text.SimpleDateFormat;
- import java.util.Date;
- import org.springframework.beans.factory.annotation.Autowired;
- import org.springframework.beans.propertyeditors.CustomDateEditor;
- import org.springframework.stereotype.Controller;
- import org.springframework.ui.ModelMap;
- import org.springframework.web.bind.WebDataBinder;
- import org.springframework.web.bind.annotation.InitBinder;
- import org.springframework.web.bind.annotation.ModelAttribute;
- import org.springframework.web.bind.annotation.RequestMapping;
- import org.springframework.web.bind.annotation.RequestMethod;
- import org.zlex.spring.domain.Account;
- import org.zlex.spring.service.AccountService;
- /**
- * 用户注册控制器
- *
- * @author <a href="mailto:zlex.dongliang@gmail.com">梁栋</a>
- * @version 1.0
- * @since 1.0
- */
- @Controller
- @RequestMapping(value = "/register.do")
- public class RegisterController {
- @Autowired
- private AccountService accountService;
- @InitBinder
- public void initBinder(WebDataBinder binder) {
- // 忽略字段绑定异常
- // binder.setIgnoreInvalidFields(true);
- DateFormat format = new SimpleDateFormat("yyyy-MM-dd");
- binder.registerCustomEditor(Date.class, "birthday",
- new CustomDateEditor(format, true));
- }
- @RequestMapping(method = RequestMethod.GET)
- public String initForm(ModelMap model) {
- Account account = new Account();
- model.addAttribute("account", account);
- // 直接跳转到登录页面
- return "account/register";
- }
- @RequestMapping(method = RequestMethod.POST)
- protected String submit(@ModelAttribute("account") Account account) {
- int id = accountService.register(account).getId();
- // 跳转到用户信息页面
- return "redirect:profile.do?id=" + id;
- }
- }
- /**
- * 2010-2-4
- */
- package org.zlex.spring.controller;
- import java.text.DateFormat;
- import java.text.SimpleDateFormat;
- import java.util.Date;
- import org.springframework.beans.factory.annotation.Autowired;
- import org.springframework.beans.propertyeditors.CustomDateEditor;
- import org.springframework.stereotype.Controller;
- import org.springframework.ui.ModelMap;
- import org.springframework.web.bind.WebDataBinder;
- import org.springframework.web.bind.annotation.InitBinder;
- import org.springframework.web.bind.annotation.ModelAttribute;
- import org.springframework.web.bind.annotation.RequestMapping;
- import org.springframework.web.bind.annotation.RequestMethod;
- import org.zlex.spring.domain.Account;
- import org.zlex.spring.service.AccountService;
- /**
- * 用户注册控制器
- *
- * @author <a href="mailto:zlex.dongliang@gmail.com">梁栋</a>
- * @version 1.0
- * @since 1.0
- */
- @Controller
- @RequestMapping(value = "/register.do")
- public class RegisterController {
- @Autowired
- private AccountService accountService;
- @InitBinder
- public void initBinder(WebDataBinder binder) {
- // 忽略字段绑定异常
- // binder.setIgnoreInvalidFields(true);
- DateFormat format = new SimpleDateFormat("yyyy-MM-dd");
- binder.registerCustomEditor(Date.class, "birthday",
- new CustomDateEditor(format, true));
- }
- @RequestMapping(method = RequestMethod.GET)
- public String initForm(ModelMap model) {
- Account account = new Account();
- model.addAttribute("account", account);
- // 直接跳转到登录页面
- return "account/register";
- }
- @RequestMapping(method = RequestMethod.POST)
- protected String submit(@ModelAttribute("account") Account account) {
- int id = accountService.register(account).getId();
- // 跳转到用户信息页面
- return "redirect:profile.do?id=" + id;
- }
- }
@InitBinder用于表单自定义属性绑定。这里我们要求输入一个日期格式的生日。
@RequestMapping(method = RequestMethod.GET)用于初始化页面。
@RequestMapping(method = RequestMethod.POST)用于提交页面。
再看注册页面
register.jsp
- <html>
- <head>
- <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
- <title>注册</title>
- <link rel="stylesheet" type="text/css" href="css/style.css" />
- <script type="text/javascript" src="js/calendar.js"></script>
- </head>
- <body>
- <fieldset><legend>用户注册</legend><form:form
- commandName="account">
- <ul>
- <li><form:label path="username">用户名:</form:label><form:input
- path="username" /></li>
- <li><form:label path="password">密码:</form:label><form:password
- path="password" /></li>
- <li><form:label path="birthday">生日:</form:label><form:input
- path="birthday" onfocus="showDate(this);" /></li>
- <li><form:label path="email">Email:</form:label><form:input
- path="email" /></li>
- <li>
- <button type="submit">注册</button>
- <button type="reset">重置</button>
- </li>
- </ul>
- </form:form></fieldset>
- </body>
- </html>
这里我用了一个JavaScript日期控制标签:
- <script type="text/javascript" src="js/calendar.js"></script>
- <script type="text/javascript" src="js/calendar.js"></script>
- <script type="text/javascript" src="js/calendar.js"></script>
使用起来就像是这样:
非常好用!!! 当然,你完全可以使用JE上的那个JS控件!
接下来稍微调整一下AccountService接口及其实现AccountServiceImpl
AccountService.java
- public interface AccountService {
- // 省略
- /**
- * 注册用户
- *
- * @param account
- * @return
- */
- @Transactional(readOnly = false, rollbackFor = DataAccessException.class)
- Account register(Account account);
- // 省略
- }
- public interface AccountService {
- // 省略
- /**
- * 注册用户
- *
- * @param account
- * @return
- */
- @Transactional(readOnly = false, rollbackFor = DataAccessException.class)
- Account register(Account account);
- // 省略
- }
- public interface AccountService {
- // 省略
- /**
- * 注册用户
- *
- * @param account
- * @return
- */
- @Transactional(readOnly = false, rollbackFor = DataAccessException.class)
- Account register(Account account);
- // 省略
- }
- @Service
- public class AccountServiceImpl implements AccountService {
- @Autowired
- private AccountDao accountDao;
- // 省略
- @Override
- public Account register(Account account) {
- accountDao.create(account);
- return accountDao.read(account.getUsername());
- }
- }
- @Service
- public class AccountServiceImpl implements AccountService {
- @Autowired
- private AccountDao accountDao;
- // 省略
- @Override
- public Account register(Account account) {
- accountDao.create(account);
- return accountDao.read(account.getUsername());
- }
- }
- @Service
- public class AccountServiceImpl implements AccountService {
- @Autowired
- private AccountDao accountDao;
- // 省略
- @Override
- public Account register(Account account) {
- accountDao.create(account);
- return accountDao.read(account.getUsername());
- }
- }
为了在插入一条记录后获得当前用户的主键,我们还得这么玩! 的确有点雷人~
从架构考虑,这是符合业务要求的实现!如果用iBatis或者Hibernate,这个问题就有数据库一次IO处理完成了!
再看看AccountDao接口及其实现AccountDaoImpl
AccountDao.java
- public interface AccountDao {
- // 省略
- /**
- * 构建用户记录
- *
- * @param account
- * @return
- */
- void create(Account account);
- }
- public interface AccountDao {
- // 省略
- /**
- * 构建用户记录
- *
- * @param account
- * @return
- */
- void create(Account account);
- }
- public interface AccountDao {
- // 省略
- /**
- * 构建用户记录
- *
- * @param account
- * @return
- */
- void create(Account account);
- }
AccountDaoImpl.java
- @Repository
- public class AccountDaoImpl implements AccountDao {
- // 省略
- @Override
- public void create(Account account) {
- String sql = "INSERT INTO account(username, password, birthday, email) VALUES(?,?,?,?)";
- jdbcTemplate.update(sql, new Object[] { account.getUsername(),
- account.getPassword(), account.getBirthday(),
- account.getEmail() });
- }
- }
- @Repository
- public class AccountDaoImpl implements AccountDao {
- // 省略
- @Override
- public void create(Account account) {
- String sql = "INSERT INTO account(username, password, birthday, email) VALUES(?,?,?,?)";
- jdbcTemplate.update(sql, new Object[] { account.getUsername(),
- account.getPassword(), account.getBirthday(),
- account.getEmail() });
- }
- }
- @Repository
- public class AccountDaoImpl implements AccountDao {
- // 省略
- @Override
- public void create(Account account) {
- String sql = "INSERT INTO account(username, password, birthday, email) VALUES(?,?,?,?)";
- jdbcTemplate.update(sql, new Object[] { account.getUsername(),
- account.getPassword(), account.getBirthday(),
- account.getEmail() });
- }
- }
来个注册演示!
注册:
信息展示:
来制造一起事故!
先看看数据库目前的状况!
在AccountDaoImpl中来个破坏!
- @Override
- public void create(Account account) {
- String sql = "INSERT INTO account(username, password, birthday, email) VALUES(?,?,?,?)";
- jdbcTemplate.update(sql, new Object[] { account.getUsername(),
- account.getPassword(), account.getBirthday(),
- account.getEmail() });
- throw new RecoverableDataAccessException("TEST");
- }
- @Override
- public void create(Account account) {
- String sql = "INSERT INTO account(username, password, birthday, email) VALUES(?,?,?,?)";
- jdbcTemplate.update(sql, new Object[] { account.getUsername(),
- account.getPassword(), account.getBirthday(),
- account.getEmail() });
- throw new RecoverableDataAccessException("TEST");
- }
- @Override
- public void create(Account account) {
- String sql = "INSERT INTO account(username, password, birthday, email) VALUES(?,?,?,?)";
- jdbcTemplate.update(sql, new Object[] { account.getUsername(),
- account.getPassword(), account.getBirthday(),
- account.getEmail() });
- throw new RecoverableDataAccessException("TEST");
- }
我们强行在执行完Insert语句后抛出DataAccessException异常(RecoverableDataAccessException)!
来个注册试试!
Spring 注解学习手札(五) 业务层事务处理
博客分类:
业务层中的关键问题在于事务控制!Spring的注解式事务处理其实很简单!
相关参考:
Spring 注解学习手札(一) 构建简单Web应用
Spring 注解学习手札(二) 控制层梳理
Spring 注解学习手札(三) 表单页面处理
Spring 注解学习手札(四) 持久层浅析
Spring 注解学习手札(五) 业务层事务处理
Spring 注解学习手札(六) 测试
Spring 注解学习手札(七) 补遗——@ResponseBody,@RequestBody,@PathVariable
Spring 注解学习手札(八) 补遗——@ExceptionHandler
这里将用到以下几个包:
commons-collections.jar
commons-dbcp.jar
commons-logging-1.1.1.jar
commons-pool.jar
jstl.jar
log4j-1.2.15.jar
mysql-connector-java-5.1.6-bin.jar
spring-aop-2.5.6.jar
spring-beans-2.5.6.jar
spring-context-2.5.6.jar
spring-context-support-2.5.6.jar
spring-core-2.5.6.jar
spring-jdbc-2.5.6.jar
spring-tx-2.5.6.jar
spring-web-2.5.6.jar
spring-webmvc-2.5.6.jar
standard.jar
主要增加了spring-aop-2.5.6.jar的AOP支持包!
之前我们在AccountService中加入了注解@Transactional标签,但是要想要真正发挥事务作用,还需要一些配置。
主要需要调整dao.xml文件
dao.xml-事务管理
- <bean
- id="transactionManager"
- class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
- p:dataSource-ref="dataSource" />
- <tx:annotation-driven
- transaction-manager="transactionManager" />
细化一下AccountService接口方法
AccountService.java
- /**
- * 2010-1-23
- */
- package org.zlex.spring.service;
- import org.springframework.dao.DataAccessException;
- import org.springframework.transaction.annotation.Transactional;
- import org.zlex.spring.domain.Account;
- /**
- * 账户业务接口
- *
- * @author <a href="mailto:zlex.dongliang@gmail.com">梁栋</a>
- * @version 1.0
- * @since 1.0
- */
- public interface AccountService {
- /**
- * 获得账户
- *
- * @param username
- * @param password
- * @return
- */
- @Transactional(readOnly = true)
- Account read(String username, String password);
- /**
- * 获得账户
- *
- * @param id
- * @return
- */
- @Transactional(readOnly = true)
- Account read(int id);
- /**
- * 注册用户
- *
- * @param account
- * @return
- */
- @Transactional(readOnly = false, rollbackFor = DataAccessException.class)
- Account register(Account account);
- }
这里我把注解@Transactional调整到了具体的方法上,也就是说这样写的话,凡是加入注解的标注的方法都属于事务配置!
Account register(Account account);用做用户注册作用!
@Transactional(readOnly = true)只读属性
@Transactional(readOnly = false, rollbackFor = DataAccessException.class)只读关闭,遇到DataAccessException异常回滚!如果不对异常进行处理,该异常将一直向上层抛出,直至抛出到页面!
如果你的Eclipse集成了SpringIDE,你可以观察一下这时的xml配置文件和AccoutServiceImpl.java的变化!
这次,来个用户注册功能演示,故意在某个位置制造一个异常,看看是否正常回滚!
先看注册控制器
RegisterController.java
- /**
- * 2010-2-4
- */
- package org.zlex.spring.controller;
- import java.text.DateFormat;
- import java.text.SimpleDateFormat;
- import java.util.Date;
- import org.springframework.beans.factory.annotation.Autowired;
- import org.springframework.beans.propertyeditors.CustomDateEditor;
- import org.springframework.stereotype.Controller;
- import org.springframework.ui.ModelMap;
- import org.springframework.web.bind.WebDataBinder;
- import org.springframework.web.bind.annotation.InitBinder;
- import org.springframework.web.bind.annotation.ModelAttribute;
- import org.springframework.web.bind.annotation.RequestMapping;
- import org.springframework.web.bind.annotation.RequestMethod;
- import org.zlex.spring.domain.Account;
- import org.zlex.spring.service.AccountService;
- /**
- * 用户注册控制器
- *
- * @author <a href="mailto:zlex.dongliang@gmail.com">梁栋</a>
- * @version 1.0
- * @since 1.0
- */
- @Controller
- @RequestMapping(value = "/register.do")
- public class RegisterController {
- @Autowired
- private AccountService accountService;
- @InitBinder
- public void initBinder(WebDataBinder binder) {
- // 忽略字段绑定异常
- // binder.setIgnoreInvalidFields(true);
- DateFormat format = new SimpleDateFormat("yyyy-MM-dd");
- binder.registerCustomEditor(Date.class, "birthday",
- new CustomDateEditor(format, true));
- }
- @RequestMapping(method = RequestMethod.GET)
- public String initForm(ModelMap model) {
- Account account = new Account();
- model.addAttribute("account", account);
- // 直接跳转到登录页面
- return "account/register";
- }
- @RequestMapping(method = RequestMethod.POST)
- protected String submit(@ModelAttribute("account") Account account) {
- int id = accountService.register(account).getId();
- // 跳转到用户信息页面
- return "redirect:profile.do?id=" + id;
- }
- }
@InitBinder用于表单自定义属性绑定。这里我们要求输入一个日期格式的生日。
@RequestMapping(method = RequestMethod.GET)用于初始化页面。
@RequestMapping(method = RequestMethod.POST)用于提交页面。
再看注册页面
register.jsp
- <html>
- <head>
- <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
- <title>注册</title>
- <link rel="stylesheet" type="text/css" href="css/style.css" />
- <script type="text/javascript" src="js/calendar.js"></script>
- </head>
- <body>
- <fieldset><legend>用户注册</legend><form:form
- commandName="account">
- <ul>
- <li><form:label path="username">用户名:</form:label><form:input
- path="username" /></li>
- <li><form:label path="password">密码:</form:label><form:password
- path="password" /></li>
- <li><form:label path="birthday">生日:</form:label><form:input
- path="birthday" onfocus="showDate(this);" /></li>
- <li><form:label path="email">Email:</form:label><form:input
- path="email" /></li>
- <li>
- <button type="submit">注册</button>
- <button type="reset">重置</button>
- </li>
- </ul>
- </form:form></fieldset>
- </body>
- </html>
这里我用了一个JavaScript日期控制标签:
- <script type="text/javascript" src="js/calendar.js"></script>
使用起来就像是这样:
非常好用!!! 当然,你完全可以使用JE上的那个JS控件!
接下来稍微调整一下AccountService接口及其实现AccountServiceImpl
AccountService.java
- public interface AccountService {
- // 省略
- /**
- * 注册用户
- *
- * @param account
- * @return
- */
- @Transactional(readOnly = false, rollbackFor = DataAccessException.class)
- Account register(Account account);
- // 省略
- }
- @Service
- public class AccountServiceImpl implements AccountService {
- @Autowired
- private AccountDao accountDao;
- // 省略
- @Override
- public Account register(Account account) {
- accountDao.create(account);
- return accountDao.read(account.getUsername());
- }
- }
为了在插入一条记录后获得当前用户的主键,我们还得这么玩! 的确有点雷人~
从架构考虑,这是符合业务要求的实现!如果用iBatis或者Hibernate,这个问题就有数据库一次IO处理完成了!
再看看AccountDao接口及其实现AccountDaoImpl
AccountDao.java
- public interface AccountDao {
- // 省略
- /**
- * 构建用户记录
- *
- * @param account
- * @return
- */
- void create(Account account);
- }
AccountDaoImpl.java
- @Repository
- public class AccountDaoImpl implements AccountDao {
- // 省略
- @Override
- public void create(Account account) {
- String sql = "INSERT INTO account(username, password, birthday, email) VALUES(?,?,?,?)";
- jdbcTemplate.update(sql, new Object[] { account.getUsername(),
- account.getPassword(), account.getBirthday(),
- account.getEmail() });
- }
- }
来个注册演示!
注册:
信息展示:
来制造一起事故!
先看看数据库目前的状况!
在AccountDaoImpl中来个破坏!
- @Override
- public void create(Account account) {
- String sql = "INSERT INTO account(username, password, birthday, email) VALUES(?,?,?,?)";
- jdbcTemplate.update(sql, new Object[] { account.getUsername(),
- account.getPassword(), account.getBirthday(),
- account.getEmail() });
- throw new RecoverableDataAccessException("TEST");
- }
我们强行在执行完Insert语句后抛出DataAccessException异常(RecoverableDataAccessException)!
来个注册试试!
点击提交看看返回的异常!
异常回滚生效!
数据库中当然是什么都没有,我就不废话了!
相关实现见附件!
相关参考:
Spring 注解学习手札(一) 构建简单Web应用
Spring 注解学习手札(二) 控制层梳理
Spring 注解学习手札(三) 表单页面处理
Spring 注解学习手札(四) 持久层浅析
Spring 注解学习手札(五) 业务层事务处理
Spring 注解学习手札(六) 测试
Spring 注解学习手札(七) 补遗——@ResponseBody,@RequestBody,@PathVariable
Spring 注解学习手札(八) 补遗——@ExceptionHandler
- spring.rar (4.4 MB)
- 下载次数: 888
Spring的@RequestBody非常牛x,可以将提交的json直接转换成POJO对象。
正好今天有这样的需求,使用一下,结果一直报415,十分头疼。
HTTP 415 错误 – 不支持的媒体类型(Unsupported media type)
我的angularJs是这样写的
$http({method: "POST",
url: url;
headers: {'Content-type': 'application/json;charset=UTF-8'},
data: scope.$modelValue})
.success(function(data, status) {
// success handle code
})
.error(function(data, status) {
// error handle code
});
url与scope.$modelValue都是项目中的代码,在这里占个坑,scope.$modelValue是一个js对象,会被angularJs转换成json字符串,
反复看angularJs的文档,又抓包分析,确认js没有问题。
在网上一查貌似是Spring的问题,有的网友说需要在*-servlet.xml中增加<mvc:annotation-driven />,一看我的项目没加,立刻加上。
当然还需要加上mvc的xml命名空间,否则该配置无法解析。
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd"
<mvc:annotation-driven />会自动注册DefaultAnnotationHandlerMapping和AnnotationMethodHandlerAdapter两个bean
AnnotationMethodHandlerAdapter将会初始化7个转换器,可以通过调用AnnotationMethodHandlerAdapter的getMessageConverts()方法来获取转换器的一个集合 List<HttpMessageConverter>
ByteArrayHttpMessageConverter
StringHttpMessageConverter
ResourceHttpMessageConverter
SourceHttpMessageConverter
XmlAwareFormHttpMessageConverter
Jaxb2RootElementHttpMessageConverter
MappingJacksonHttpMessageConverter
对于json的解析就是通过MappingJacksonHttpMessageConverter转换器完成的。
只添加<mvc:annotation-driven />还不行,需要在classpath环境中能找到Jackson包,用maven配置如下
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-mapper-asl</artifactId>
<version>1.9.8</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
至此问题解决,附上Spring代码
@RequestMapping(value = "/testjson", method = RequestMethod.POST, consumes = "application/json")
@ResponseBody
public void testJson(@RequestBody JsonInfo jsonInfo,
HttpServletRequest request, HttpServletResponse response)
{
//handle jsonInfo object instance
}
从下文得到帮助,对作者表示感谢:)
http://snowolf.iteye.com/blog/1628861
相关参考:
Spring 注解学习手札(一) 构建简单Web应用
Spring 注解学习手札(二) 控制层梳理
Spring 注解学习手札(三) 表单页面处理
Spring 注解学习手札(四) 持久层浅析
Spring 注解学习手札(五) 业务层事务处理
Spring 注解学习手札(六) 测试
Spring 注解学习手札(七) 补遗——@ResponseBody,@RequestBody,@PathVariable
Spring 注解学习手札(八) 补遗——@ExceptionHandler
SpringMVC层跟JSon结合,几乎不需要做什么配置,代码实现也相当简洁。再也不用为了组装协议而劳烦辛苦了!
一、Spring注解@ResponseBody,@RequestBody和HttpMessageConverter
Spring 3.X系列增加了新注解@ResponseBody,@RequestBody
- @RequestBody 将HTTP请求正文转换为适合的HttpMessageConverter对象。
- @ResponseBody 将内容或对象作为 HTTP 响应正文返回,并调用适合HttpMessageConverter的Adapter转换对象,写入输出流。
HttpMessageConverter接口,需要开启<mvc:annotation-driven />。
AnnotationMethodHandlerAdapter将会初始化7个转换器,可以通过调用AnnotationMethodHandlerAdapter的getMessageConverts()方法来获取转换器的一个集合 List<HttpMessageConverter>
StringHttpMessageConverter
ResourceHttpMessageConverter
SourceHttpMessageConverter
XmlAwareFormHttpMessageConverter
Jaxb2RootElementHttpMessageConverter
MappingJacksonHttpMessageConverter
可以理解为,只要有对应协议的解析器,你就可以通过几行配置,几个注解完成协议——对象的转换工作!
PS:Spring默认的json协议解析由Jackson完成。
二、servlet.xml配置
Spring的配置文件,简洁到了极致,对于当前这个需求只需要三行核心配置:
- <context:component-scan base-package="org.zlex.json.controller" />
- <context:annotation-config />
- <mvc:annotation-driven />
三、pom.xml配置
闲言少叙,先说依赖配置,这里以Json+Spring为参考:
pom.xml
- <dependency>
- <groupId>org.springframework</groupId>
- <artifactId>spring-webmvc</artifactId>
- <version>3.1.2.RELEASE</version>
- <type>jar</type>
- <scope>compile</scope>
- </dependency>
- <dependency>
- <groupId>org.codehaus.jackson</groupId>
- <artifactId>jackson-mapper-asl</artifactId>
- <version>1.9.8</version>
- <type>jar</type>
- <scope>compile</scope>
- </dependency>
- <dependency>
- <groupId>log4j</groupId>
- <artifactId>log4j</artifactId>
- <version>1.2.17</version>
- <scope>compile</scope>
- </dependency>
主要需要spring-webmvc、jackson-mapper-asl两个包,其余依赖包Maven会帮你完成。至于log4j,我还是需要看日志嘛。
包依赖图:
至于版本,看项目需要吧!
四、代码实现
域对象:
- public class Person implements Serializable {
- private int id;
- private String name;
- private boolean status;
- public Person() {
- // do nothing
- }
- }
这里需要一个空构造,由Spring转换对象时,进行初始化。
@ResponseBody,@RequestBody,@PathVariable
控制器:
- @Controller
- public class PersonController {
- /**
- * 查询个人信息
- *
- * @param id
- * @return
- */
- @RequestMapping(value = "/person/profile/{id}/{name}/{status}", method = RequestMethod.GET)
- public @ResponseBody
- Person porfile(@PathVariable int id, @PathVariable String name,
- @PathVariable boolean status) {
- return new Person(id, name, status);
- }
- /**
- * 登录
- *
- * @param person
- * @return
- */
- @RequestMapping(value = "/person/login", method = RequestMethod.POST)
- public @ResponseBody
- Person login(@RequestBody Person person) {
- return person;
- }
- }
备注:@RequestMapping(value = "/person/profile/{id}/{name}/{status}", method = RequestMethod.GET)中的{id}/{name}/{status}与@PathVariable int id, @PathVariable String name,@PathVariable boolean status一一对应,按名匹配。 这是restful式风格。
如果映射名称有所不一,可以参考如下方式:
- @RequestMapping(value = "/person/profile/{id}", method = RequestMethod.GET)
- public @ResponseBody
- Person porfile(@PathVariable("id") int uid) {
- return new Person(uid, name, status);
- }
- GET模式下,这里使用了@PathVariable绑定输入参数,非常适合Restful风格。因为隐藏了参数与路径的关系,可以提升网站的安全性,静态化页面,降低恶意攻击风险。
- POST模式下,使用@RequestBody绑定请求对象,Spring会帮你进行协议转换,将Json、Xml协议转换成你需要的对象。
- @ResponseBody可以标注任何对象,由Srping完成对象——协议的转换。
做个页面测试下:
JS
- $(document).ready(function() {
- $("#profile").click(function() {
- profile();
- });
- $("#login").click(function() {
- login();
- });
- });
- function profile() {
- var url = 'http://localhost:8080/spring-json/json/person/profile/';
- var query = $('#id').val() + '/' + $('#name').val() + '/'
- + $('#status').val();
- url += query;
- alert(url);
- $.get(url, function(data) {
- alert("id: " + data.id + "\nname: " + data.name + "\nstatus: "
- + data.status);
- });
- }
- function login() {
- var mydata = '{"name":"' + $('#name').val() + '","id":"'
- + $('#id').val() + '","status":"' + $('#status').val() + '"}';
- alert(mydata);
- $.ajax({
- type : 'POST',
- contentType : 'application/json',
- url : 'http://localhost:8080/spring-json/json/person/login',
- processData : false,
- dataType : 'json',
- data : mydata,
- success : function(data) {
- alert("id: " + data.id + "\nname: " + data.name + "\nstatus: "
- + data.status);
- },
- error : function() {
- alert('Err...');
- }
- });
Table
- <table>
- <tr>
- <td>id</td>
- <td><input id="id" value="100" /></td>
- </tr>
- <tr>
- <td>name</td>
- <td><input id="name" value="snowolf" /></td>
- </tr>
- <tr>
- <td>status</td>
- <td><input id="status" value="true" /></td>
- </tr>
- <tr>
- <td><input type="button" id="profile" value="Profile——GET" /></td>
- <td><input type="button" id="login" value="Login——POST" /></td>
- </tr>
- </table>
四、简单测试
Get方式测试:
Post方式测试:
五、常见错误
POST操作时,我用$.post()方式,屡次失败,一直报各种异常:
org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'application/x-www-form-urlencoded;charset=UTF-8' not supported
org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'application/x-www-form-urlencoded;charset=UTF-8' not supported
直接用$.post()直接请求会有点小问题,尽管我标识为json协议,但实际上提交的ContentType还是application/x-www-form-urlencoded。需要使用$.ajaxSetup()标示下ContentType。
- function login() {
- var mydata = '{"name":"' + $('#name').val() + '","id":"'
- + $('#id').val() + '","status":"' + $('#status').val() + '"}';
- alert(mydata);
- $.ajaxSetup({
- contentType : 'application/json'
- });
- $.post('http://localhost:8080/spring-json/json/person/login', mydata,
- function(data) {
- alert("id: " + data.id + "\nname: " + data.name
- + "\nstatus: " + data.status);
- }, 'json');
- };
效果是一样!
详见附件!
相关参考:
Spring 注解学习手札(一) 构建简单Web应用
Spring 注解学习手札(二) 控制层梳理
Spring 注解学习手札(三) 表单页面处理
Spring 注解学习手札(四) 持久层浅析
Spring 注解学习手札(五) 业务层事务处理
Spring 注解学习手札(六) 测试
Spring 注解学习手札(七) 补遗——@ResponseBody,@RequestBody,@PathVariable
Spring 注解学习手札(八) 补遗——@ExceptionHandler
- spring-json.zip (65.1 KB)
- 下载次数: 910
@RequestParam @RequestBody @PathVariable 等参数绑定注解详解(转)
引言:
接上一篇文章,对@RequestMapping进行地址映射讲解之后,该篇主要讲解request 数据到handler method 参数数据的绑定所用到的注解和什么情形下使用;
简介:
handler method 参数绑定常用的注解,我们根据他们处理的Request的不同内容部分分为四类:(主要讲解常用类型)
A、处理requet uri 部分(这里指uri template中variable,不含queryString部分)的注解: @PathVariable;
B、处理request header部分的注解: @RequestHeader, @CookieValue;
C、处理request body部分的注解:@RequestParam, @RequestBody;
D、处理attribute类型是注解: @SessionAttributes, @ModelAttribute;
1、 @PathVariable
当使用@RequestMapping URI template 样式映射时, 即 someUrl/{paramId}, 这时的paramId可通过 @Pathvariable注解绑定它传过来的值到方法的参数上。
示例代码:
@Controller
@RequestMapping("/owners/{ownerId}")
public class RelativePathUriTemplateController { @RequestMapping("/pets/{petId}")
public void findPet(@PathVariable String ownerId, @PathVariable String petId, Model model) {
// implementation omitted
}
}
上面代码把URI template 中变量 ownerId的值和petId的值,绑定到方法的参数上。若方法参数名称和需要绑定的uri template中变量名称不一致,需要在@PathVariable("name")指定uri template中的名称。
2、 @RequestHeader、@CookieValue
@RequestHeader 注解,可以把Request请求header部分的值绑定到方法的参数上。
示例代码:
这是一个Request 的header部分:
Host localhost:8080
Accept text/html,application/xhtml+xml,application/xml;q=0.9
Accept-Language fr,en-gb;q=0.7,en;q=0.3
Accept-Encoding gzip,deflate
Accept-Charset ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive 300
@RequestMapping("/displayHeaderInfo.do")
public void displayHeaderInfo(@RequestHeader("Accept-Encoding") String encoding,
@RequestHeader("Keep-Alive") long keepAlive) { //... }
上面的代码,把request header部分的 Accept-Encoding的值,绑定到参数encoding上了, Keep-Alive header的值绑定到参数keepAlive上。
@CookieValue 可以把Request header中关于cookie的值绑定到方法的参数上。
例如有如下Cookie值:
JSESSIONID=415A4AC178C59DACE0B2C9CA727CDD84
参数绑定的代码:
@RequestMapping("/displayHeaderInfo.do")
public void displayHeaderInfo(@CookieValue("JSESSIONID") String cookie) { //... }
即把JSESSIONID的值绑定到参数cookie上。
3、@RequestParam, @RequestBody
@RequestParam
A) 常用来处理简单类型的绑定,通过Request.getParameter() 获取的String可直接转换为简单类型的情况( String--> 简单类型的转换操作由ConversionService配置的转换器来完成);因为使用request.getParameter()方式获取参数,所以可以处理get 方式中queryString的值,也可以处理post方式中 body data的值;
B)用来处理Content-Type: 为 application/x-www-form-urlencoded
编码的内容,提交方式GET、POST;
C) 该注解有两个属性: value、required; value用来指定要传入值的id名称,required用来指示参数是否必须绑定;
示例代码:
@Controller
@RequestMapping("/pets")
@SessionAttributes("pet")
public class EditPetForm { // ... @RequestMapping(method = RequestMethod.GET)
public String setupForm(@RequestParam("petId") int petId, ModelMap model) {
Pet pet = this.clinic.loadPet(petId);
model.addAttribute("pet", pet);
return "petForm";
} // ...
@RequestBody
该注解常用来处理Content-Type: 不是application/x-www-form-urlencoded
编码的内容,例如application/json, application/xml等;
它是通过使用HandlerAdapter 配置的HttpMessageConverters
来解析post data body,然后绑定到相应的bean上的。
因为配置有FormHttpMessageConverter,所以也可以用来处理 application/x-www-form-urlencoded
的内容,处理完的结果放在一个MultiValueMap<String, String>里,这种情况在某些特殊需求下使用,详情查看FormHttpMessageConverter api;
示例代码:
@RequestMapping(value = "/something", method = RequestMethod.PUT)
public void handle(@RequestBody String body, Writer writer) throws IOException {
writer.write(body);
}
4、@SessionAttributes, @ModelAttribute
@SessionAttributes:
该注解用来绑定HttpSession中的attribute对象的值,便于在方法中的参数里使用。
该注解有value、types两个属性,可以通过名字和类型指定要使用的attribute 对象;
示例代码:
@Controller
@RequestMapping("/editPet.do")
@SessionAttributes("pet")
public class EditPetForm {
// ...
}
@ModelAttribute
该注解有两个用法,一个是用于方法上,一个是用于参数上;
用于方法上时: 通常用来在处理@RequestMapping之前,为请求绑定需要从后台查询的model;
用于参数上时: 用来通过名称对应,把相应名称的值绑定到注解的参数bean上;要绑定的值来源于:
A) @SessionAttributes 启用的attribute 对象上;
B) @ModelAttribute 用于方法上时指定的model对象;
C) 上述两种情况都没有时,new一个需要绑定的bean对象,然后把request中按名称对应的方式把值绑定到bean中。
用到方法上@ModelAttribute的示例代码:
// Add one attribute
// The return value of the method is added to the model under the name "account"
// You can customize the name via @ModelAttribute("myAccount") @ModelAttribute
public Account addAccount(@RequestParam String number) {
return accountManager.findAccount(number);
}
这种方式实际的效果就是在调用@RequestMapping的方法之前,为request对象的model里put(“account”, Account);
用在参数上的@ModelAttribute示例代码:
@RequestMapping(value="/owners/{ownerId}/pets/{petId}/edit", method = RequestMethod.POST)
public String processSubmit(@ModelAttribute Pet pet) { }
首先查询 @SessionAttributes有无绑定的Pet对象,若没有则查询@ModelAttribute方法层面上是否绑定了Pet对象,若没有则将URI template中的值按对应的名称绑定到Pet对象的各属性上。
补充讲解:
问题: 在不给定注解的情况下,参数是怎样绑定的?
通过分析AnnotationMethodHandlerAdapter和RequestMappingHandlerAdapter的源代码发现,方法的参数在不给定参数的情况下:
若要绑定的对象时简单类型: 调用@RequestParam来处理的。
若要绑定的对象时复杂类型: 调用@ModelAttribute来处理的。
这里的简单类型指java的原始类型(boolean, int 等)、原始类型对象(Boolean, Int等)、String、Date等ConversionService里可以直接String转换成目标对象的类型;
下面贴出AnnotationMethodHandlerAdapter中绑定参数的部分源代码:
private Object[] resolveHandlerArguments(Method handlerMethod, Object handler,
NativeWebRequest webRequest, ExtendedModelMap implicitModel) throws Exception { Class[] paramTypes = handlerMethod.getParameterTypes();
Object[] args = new Object[paramTypes.length]; for (int i = 0; i < args.length; i++) {
MethodParameter methodParam = new MethodParameter(handlerMethod, i);
methodParam.initParameterNameDiscovery(this.parameterNameDiscoverer);
GenericTypeResolver.resolveParameterType(methodParam, handler.getClass());
String paramName = null;
String headerName = null;
boolean requestBodyFound = false;
String cookieName = null;
String pathVarName = null;
String attrName = null;
boolean required = false;
String defaultValue = null;
boolean validate = false;
Object[] validationHints = null;
int annotationsFound = 0;
Annotation[] paramAnns = methodParam.getParameterAnnotations(); for (Annotation paramAnn : paramAnns) {
if (RequestParam.class.isInstance(paramAnn)) {
RequestParam requestParam = (RequestParam) paramAnn;
paramName = requestParam.value();
required = requestParam.required();
defaultValue = parseDefaultValueAttribute(requestParam.defaultValue());
annotationsFound++;
}
else if (RequestHeader.class.isInstance(paramAnn)) {
RequestHeader requestHeader = (RequestHeader) paramAnn;
headerName = requestHeader.value();
required = requestHeader.required();
defaultValue = parseDefaultValueAttribute(requestHeader.defaultValue());
annotationsFound++;
}
else if (RequestBody.class.isInstance(paramAnn)) {
requestBodyFound = true;
annotationsFound++;
}
else if (CookieValue.class.isInstance(paramAnn)) {
CookieValue cookieValue = (CookieValue) paramAnn;
cookieName = cookieValue.value();
required = cookieValue.required();
defaultValue = parseDefaultValueAttribute(cookieValue.defaultValue());
annotationsFound++;
}
else if (PathVariable.class.isInstance(paramAnn)) {
PathVariable pathVar = (PathVariable) paramAnn;
pathVarName = pathVar.value();
annotationsFound++;
}
else if (ModelAttribute.class.isInstance(paramAnn)) {
ModelAttribute attr = (ModelAttribute) paramAnn;
attrName = attr.value();
annotationsFound++;
}
else if (Value.class.isInstance(paramAnn)) {
defaultValue = ((Value) paramAnn).value();
}
else if (paramAnn.annotationType().getSimpleName().startsWith("Valid")) {
validate = true;
Object value = AnnotationUtils.getValue(paramAnn);
validationHints = (value instanceof Object[] ? (Object[]) value : new Object[] {value});
}
} if (annotationsFound > 1) {
throw new IllegalStateException("Handler parameter annotations are exclusive choices - " +
"do not specify more than one such annotation on the same parameter: " + handlerMethod);
} if (annotationsFound == 0) {// 若没有发现注解
Object argValue = resolveCommonArgument(methodParam, webRequest); //判断WebRquest是否可赋值给参数
if (argValue != WebArgumentResolver.UNRESOLVED) {
args[i] = argValue;
}
else if (defaultValue != null) {
args[i] = resolveDefaultValue(defaultValue);
}
else {
Class<?> paramType = methodParam.getParameterType();
if (Model.class.isAssignableFrom(paramType) || Map.class.isAssignableFrom(paramType)) {
if (!paramType.isAssignableFrom(implicitModel.getClass())) {
throw new IllegalStateException("Argument [" + paramType.getSimpleName() + "] is of type " +
"Model or Map but is not assignable from the actual model. You may need to switch " +
"newer MVC infrastructure classes to use this argument.");
}
args[i] = implicitModel;
}
else if (SessionStatus.class.isAssignableFrom(paramType)) {
args[i] = this.sessionStatus;
}
else if (HttpEntity.class.isAssignableFrom(paramType)) {
args[i] = resolveHttpEntityRequest(methodParam, webRequest);
}
else if (Errors.class.isAssignableFrom(paramType)) {
throw new IllegalStateException("Errors/BindingResult argument declared " +
"without preceding model attribute. Check your handler method signature!");
}
else if (BeanUtils.isSimpleProperty(paramType)) {// 判断是否参数类型是否是简单类型,若是在使用@RequestParam方式来处理,否则使用@ModelAttribute方式处理
paramName = "";
}
else {
attrName = "";
}
}
} if (paramName != null) {
args[i] = resolveRequestParam(paramName, required, defaultValue, methodParam, webRequest, handler);
}
else if (headerName != null) {
args[i] = resolveRequestHeader(headerName, required, defaultValue, methodParam, webRequest, handler);
}
else if (requestBodyFound) {
args[i] = resolveRequestBody(methodParam, webRequest, handler);
}
else if (cookieName != null) {
args[i] = resolveCookieValue(cookieName, required, defaultValue, methodParam, webRequest, handler);
}
else if (pathVarName != null) {
args[i] = resolvePathVariable(pathVarName, methodParam, webRequest, handler);
}
else if (attrName != null) {
WebDataBinder binder =
resolveModelAttribute(attrName, methodParam, implicitModel, webRequest, handler);
boolean assignBindingResult = (args.length > i + 1 && Errors.class.isAssignableFrom(paramTypes[i + 1]));
if (binder.getTarget() != null) {
doBind(binder, webRequest, validate, validationHints, !assignBindingResult);
}
args[i] = binder.getTarget();
if (assignBindingResult) {
args[i + 1] = binder.getBindingResult();
i++;
}
implicitModel.putAll(binder.getBindingResult().getModel());
}
} return args;
}
RequestMappingHandlerAdapter中使用的参数绑定,代码稍微有些不同,有兴趣的同仁可以分析下,最后处理的结果都是一样的。
示例:
@RequestMapping ({"/", "/home"})
public String showHomePage(String key){ logger.debug("key="+key); return "home";
}
这种情况下,就调用默认的@RequestParam来处理。
@RequestMapping (method = RequestMethod.POST)
public String doRegister(User user){
if(logger.isDebugEnabled()){
logger.debug("process url[/user], method[post] in "+getClass());
logger.debug(user);
} return "user";
}
这种情况下,就调用@ModelAttribute来处理
@RequestBody
作用:
i) 该注解用于读取Request请求的body部分数据,使用系统默认配置的HttpMessageConverter进行解析,然后把相应的数据绑定到要返回的对象上;
ii) 再把HttpMessageConverter返回的对象数据绑定到 controller中方法的参数上。
使用时机:
A) GET、POST方式提时, 根据request header Content-Type的值来判断:
- application/x-www-form-urlencoded, 可选(即非必须,因为这种情况的数据@RequestParam, @ModelAttribute也可以处理,当然@RequestBody也能处理);
- multipart/form-data, 不能处理(即使用@RequestBody不能处理这种格式的数据);
- 其他格式, 必须(其他格式包括application/json, application/xml等。这些格式的数据,必须使用@RequestBody来处理);
B) PUT方式提交时, 根据request header Content-Type的值来判断:
- application/x-www-form-urlencoded, 必须;
- multipart/form-data, 不能处理;
- 其他格式, 必须;
说明:request的body部分的数据编码格式由header部分的Content-Type指定;
@ResponseBody
作用:
该注解用于将Controller的方法返回的对象,通过适当的HttpMessageConverter转换为指定格式后,写入到Response对象的body数据区。
使用时机:
返回的数据不是html标签的页面,而是其他某种格式的数据时(如json、xml等)使用;
HttpMessageConverter
<span style="font-family:Microsoft YaHei;">/**
* Strategy interface that specifies a converter that can convert from and to HTTP requests and responses.
*
* @author Arjen Poutsma
* @author Juergen Hoeller
* @since 3.0
*/
public interface HttpMessageConverter<T> { /**
* Indicates whether the given class can be read by this converter.
* @param clazz the class to test for readability
* @param mediaType the media type to read, can be {@code null} if not specified.
* Typically the value of a {@code Content-Type} header.
* @return {@code true} if readable; {@code false} otherwise
*/
boolean canRead(Class<?> clazz, MediaType mediaType); /**
* Indicates whether the given class can be written by this converter.
* @param clazz the class to test for writability
* @param mediaType the media type to write, can be {@code null} if not specified.
* Typically the value of an {@code Accept} header.
* @return {@code true} if writable; {@code false} otherwise
*/
boolean canWrite(Class<?> clazz, MediaType mediaType); /**
* Return the list of {@link MediaType} objects supported by this converter.
* @return the list of supported media types
*/
List<MediaType> getSupportedMediaTypes(); /**
* Read an object of the given type form the given input message, and returns it.
* @param clazz the type of object to return. This type must have previously been passed to the
* {@link #canRead canRead} method of this interface, which must have returned {@code true}.
* @param inputMessage the HTTP input message to read from
* @return the converted object
* @throws IOException in case of I/O errors
* @throws HttpMessageNotReadableException in case of conversion errors
*/
T read(Class<? extends T> clazz, HttpInputMessage inputMessage)
throws IOException, HttpMessageNotReadableException; /**
* Write an given object to the given output message.
* @param t the object to write to the output message. The type of this object must have previously been
* passed to the {@link #canWrite canWrite} method of this interface, which must have returned {@code true}.
* @param contentType the content type to use when writing. May be {@code null} to indicate that the
* default content type of the converter must be used. If not {@code null}, this media type must have
* previously been passed to the {@link #canWrite canWrite} method of this interface, which must have
* returned {@code true}.
* @param outputMessage the message to write to
* @throws IOException in case of I/O errors
* @throws HttpMessageNotWritableException in case of conversion errors
*/
void write(T t, MediaType contentType, HttpOutputMessage outputMessage)
throws IOException, HttpMessageNotWritableException; }
</span>
该接口定义了四个方法,分别是读取数据时的 canRead(), read() 和 写入数据时的canWrite(), write()方法。
在使用 <mvc:annotation-driven />标签配置时,默认配置了RequestMappingHandlerAdapter(注意是
RequestMappingHandlerAdapter
不是AnnotationMethodHandlerAdapter,详情查看Spring 3.1 document “16.14 Configuring Spring MVC”章节),并为他配置了一下默认的HttpMessageConverter:
ByteArrayHttpMessageConverter converts byte arrays. StringHttpMessageConverter converts strings. ResourceHttpMessageConverter converts to/from org.springframework.core.io.Resource for all media types. SourceHttpMessageConverter converts to/from a javax.xml.transform.Source. FormHttpMessageConverter converts form data to/from a MultiValueMap<String, String>. Jaxb2RootElementHttpMessageConverter converts Java objects to/from XML — added if JAXB2 is present on the classpath. MappingJacksonHttpMessageConverter converts to/from JSON — added if Jackson is present on the classpath. AtomFeedHttpMessageConverter converts Atom feeds — added if Rome is present on the classpath. RssChannelHttpMessageConverter converts RSS feeds — added if Rome is present on the classpath.
ByteArrayHttpMessageConverter: 负责读取二进制格式的数据和写出二进制格式的数据;
StringHttpMessageConverter: 负责读取字符串格式的数据和写出二进制格式的数据;
ResourceHttpMessageConverter:负责读取资源文件和写出资源文件数据;
FormHttpMessageConverter: 负责读取form提交的数据(能读取的数据格式为 application/x-www-form-urlencoded,不能读取multipart/form-data格式数据);负责写入application/x-www-from-urlencoded和multipart/form-data格式的数据;
MappingJacksonHttpMessageConverter: 负责读取和写入json格式的数据;
SouceHttpMessageConverter: 负责读取和写入 xml 中javax.xml.transform.Source定义的数据;
Jaxb2RootElementHttpMessageConverter: 负责读取和写入xml 标签格式的数据;
AtomFeedHttpMessageConverter: 负责读取和写入Atom格式的数据;
RssChannelHttpMessageConverter: 负责读取和写入RSS格式的数据;
当使用@RequestBody和@ResponseBody注解时,
RequestMappingHandlerAdapter
就使用它们来进行读取或者写入相应格式的数据。
HttpMessageConverter匹配过程:
@RequestBody注解时: 根据Request对象header部分的Content-Type类型,逐一匹配合适的HttpMessageConverter来读取数据;
spring 3.1源代码如下:
private Object readWithMessageConverters(MethodParameter methodParam, HttpInputMessage inputMessage, Class paramType)
throws Exception { MediaType contentType = inputMessage.getHeaders().getContentType();
if (contentType == null) {
StringBuilder builder = new StringBuilder(ClassUtils.getShortName(methodParam.getParameterType()));
String paramName = methodParam.getParameterName();
if (paramName != null) {
builder.append(' ');
builder.append(paramName);
}
throw new HttpMediaTypeNotSupportedException(
"Cannot extract parameter (" + builder.toString() + "): no Content-Type found");
} List<MediaType> allSupportedMediaTypes = new ArrayList<MediaType>();
if (this.messageConverters != null) {
for (HttpMessageConverter<?> messageConverter : this.messageConverters) {
allSupportedMediaTypes.addAll(messageConverter.getSupportedMediaTypes());
if (messageConverter.canRead(paramType, contentType)) {
if (logger.isDebugEnabled()) {
logger.debug("Reading [" + paramType.getName() + "] as \"" + contentType
+"\" using [" + messageConverter + "]");
}
return messageConverter.read(paramType, inputMessage);
}
}
}
throw new HttpMediaTypeNotSupportedException(contentType, allSupportedMediaTypes);
}
@ResponseBody注解时: 根据Request对象header部分的Accept属性(逗号分隔),逐一按accept中的类型,去遍历找到能处理的HttpMessageConverter;
源代码如下:
private void writeWithMessageConverters(Object returnValue,
HttpInputMessage inputMessage, HttpOutputMessage outputMessage)
throws IOException, HttpMediaTypeNotAcceptableException {
List<MediaType> acceptedMediaTypes = inputMessage.getHeaders().getAccept();
if (acceptedMediaTypes.isEmpty()) {
acceptedMediaTypes = Collections.singletonList(MediaType.ALL);
}
MediaType.sortByQualityValue(acceptedMediaTypes);
Class<?> returnValueType = returnValue.getClass();
List<MediaType> allSupportedMediaTypes = new ArrayList<MediaType>();
if (getMessageConverters() != null) {
for (MediaType acceptedMediaType : acceptedMediaTypes) {
for (HttpMessageConverter messageConverter : getMessageConverters()) {
if (messageConverter.canWrite(returnValueType, acceptedMediaType)) {
messageConverter.write(returnValue, acceptedMediaType, outputMessage);
if (logger.isDebugEnabled()) {
MediaType contentType = outputMessage.getHeaders().getContentType();
if (contentType == null) {
contentType = acceptedMediaType;
}
logger.debug("Written [" + returnValue + "] as \"" + contentType +
"\" using [" + messageConverter + "]");
}
this.responseArgumentUsed = true;
return;
}
}
}
for (HttpMessageConverter messageConverter : messageConverters) {
allSupportedMediaTypes.addAll(messageConverter.getSupportedMediaTypes());
}
}
throw new HttpMediaTypeNotAcceptableException(allSupportedMediaTypes);
}
补充:
MappingJacksonHttpMessageConverter 调用了 objectMapper.writeValue(OutputStream stream, Object)方法,使用@ResponseBody注解返回的对象就传入Object参数内。若返回的对象为已经格式化好的json串时,不使用@RequestBody注解,而应该这样处理:
1、response.setContentType("application/json; charset=UTF-8");
2、response.getWriter().print(jsonStr);
直接输出到body区,然后的视图为void。
前段时间项目中用到了RESTful模式来开发程序,但是当用POST、PUT模式提交数据时,发现服务器端接受不到提交的数据(服务器端参数绑定没有加任何注解),查看了提交方式为application/json, 而且服务器端通过request.getReader() 打出的数据里确实存在浏览器提交的数据。为了找出原因,便对参数绑定(@RequestParam、 @RequestBody、 @RequestHeader 、 @PathVariable)进行了研究,同时也看了一下HttpMessageConverter的相关内容,在此一并总结。
简介:
@RequestMapping
RequestMapping是一个用来处理请求地址映射的注解,可用于类或方法上。用于类上,表示类中的所有响应请求的方法都是以该地址作为父路径。
RequestMapping注解有六个属性,下面我们把她分成三类进行说明。
1、 value, method;
value: 指定请求的实际地址,指定的地址可以是URI Template 模式(后面将会说明);
method: 指定请求的method类型, GET、POST、PUT、DELETE等;
2、 consumes,produces;
consumes: 指定处理请求的提交内容类型(Content-Type),例如application/json, text/html;
produces: 指定返回的内容类型,仅当request请求头中的(Accept)类型中包含该指定类型才返回;
3、 params,headers;
params: 指定request中必须包含某些参数值是,才让该方法处理。
headers: 指定request中必须包含某些指定的header值,才能让该方法处理请求。
示例:
1、value / method 示例
默认RequestMapping("....str...")即为value的值;
@Controller
@RequestMapping("/appointments")
public class AppointmentsController { private AppointmentBook appointmentBook; @Autowired
public AppointmentsController(AppointmentBook appointmentBook) {
this.appointmentBook = appointmentBook;
} @RequestMapping(method = RequestMethod.GET)
public Map<String, Appointment> get() {
return appointmentBook.getAppointmentsForToday();
} @RequestMapping(value="/{day}", method = RequestMethod.GET)
public Map<String, Appointment> getForDay(@PathVariable @DateTimeFormat(iso=ISO.DATE) Date day, Model model) {
return appointmentBook.getAppointmentsForDay(day);
} @RequestMapping(value="/new", method = RequestMethod.GET)
public AppointmentForm getNewForm() {
return new AppointmentForm();
} @RequestMapping(method = RequestMethod.POST)
public String add(@Valid AppointmentForm appointment, BindingResult result) {
if (result.hasErrors()) {
return "appointments/new";
}
appointmentBook.addAppointment(appointment);
return "redirect:/appointments";
}
}
value的uri值为以下三类:
A) 可以指定为普通的具体值;
B) 可以指定为含有某变量的一类值(URI Template Patterns with Path Variables);
C) 可以指定为含正则表达式的一类值( URI Template Patterns with Regular Expressions);
example B)
@RequestMapping(value="/owners/{ownerId}", method=RequestMethod.GET)
public String findOwner(@PathVariable String ownerId, Model model) {
Owner owner = ownerService.findOwner(ownerId);
model.addAttribute("owner", owner);
return "displayOwner";
}
example C)
@RequestMapping("/spring-web/{symbolicName:[a-z-]+}-{version:\d\.\d\.\d}.{extension:\.[a-z]}")
public void handle(@PathVariable String version, @PathVariable String extension) {
// ...
}
}
2 consumes、produces 示例
cousumes的样例:
@Controller
@RequestMapping(value = "/pets", method = RequestMethod.POST, consumes="application/json")
public void addPet(@RequestBody Pet pet, Model model) {
// implementation omitted
}
方法仅处理request Content-Type为“application/json”类型的请求。
produces的样例:
@Controller
@RequestMapping(value = "/pets/{petId}", method = RequestMethod.GET, produces="application/json")
@ResponseBody
public Pet getPet(@PathVariable String petId, Model model) {
// implementation omitted
}
方法仅处理request请求中Accept头中包含了"application/json"的请求,同时暗示了返回的内容类型为application/json;
3 params、headers 示例
params的样例:
@Controller
@RequestMapping("/owners/{ownerId}")
public class RelativePathUriTemplateController { @RequestMapping(value = "/pets/{petId}", method = RequestMethod.GET, params="myParam=myValue")
public void findPet(@PathVariable String ownerId, @PathVariable String petId, Model model) {
// implementation omitted
}
}
仅处理请求中包含了名为“myParam”,值为“myValue”的请求;
headers的样例:
@Controller
@RequestMapping("/owners/{ownerId}")
public class RelativePathUriTemplateController { @RequestMapping(value = "/pets", method = RequestMethod.GET, headers="Referer=http://www.ifeng.com/")
public void findPet(@PathVariable String ownerId, @PathVariable String petId, Model model) {
// implementation omitted
}
}
仅处理request的header中包含了指定“Refer”请求头和对应值为“http://www.ifeng.com/
”的请求;
http://www.codeweblog.com/stag/spring-requestmapping-method-requestmethod-post/
Rest介绍
/blog/1 HTTP DELETE => 删除 id = 1的blog
/blog/1 HTTP PUT => 更新id = 1的blog
/blog HTTP POST => 新增BLOG
以下详细解一下spring rest使用.
首先,我们带着如下两个问题查看本文。
1.如何在java构造没有扩展名的RESTful url,如 /forms/1,而不是 /forms/1.do
2.浏览器的form标签不支持提交delete,put请求,如何曲线解决
springmvc rest 实现
springmvc的resturl是通过@RequestMapping 及@PathVariable annotation提供的,
通过如@RequestMapping(value="/blog /{id}",method=RequestMethod.DELETE)即可处理/blog/1 的delete请求.
2public ModelAndView delete(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) {
3 blogManager.removeById(id);
4 return new ModelAndView(LIST_ACTION);
5}
@RequestMapping @PathVariable如果URL中带参数,则配合使用,如
2public ModelAndView delete(@PathVariable("blogId") Long blogId,@PathVariable("msgId") Long msgId,HttpServletRequest request,HttpServletResponse response) {
3}
1.springmvc web.xml配置
2 <servlet-mapping>
3 <servlet-name>default</servlet-name>
4 <url-pattern>/static/*</url-pattern>
5 </servlet-mapping>
6 <servlet>
7 <servlet-name>springmvc</servlet-name>
8 <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
9 <load-on-startup>1</load-on-startup>
10 </servlet>
11
12 <!-- URL重写filter,用于将访问静态资源http://localhost/foo.css 转为http://localhost/static/foo.css -->
13 <filter>
14 <filter-name>UrlRewriteFilter</filter-name>
15 <filter-class>org.tuckey.web.filters.urlrewrite.UrlRewriteFilter</filter-class>
16 <init-param>
17 <param-name>confReloadCheckInterval</param-name>
18 <param-value>60</param-value>
19 </init-param>
20 <init-param>
21 <param-name>logLevel</param-name>
22 <param-value>DEBUG</param-value>
23 </init-param>
24 </filter>
25 <filter-mapping>
26 <filter-name>UrlRewriteFilter</filter-name>
27 <url-pattern>/*</url-pattern>
28 </filter-mapping>
29
30 <!-- 覆盖default servlet的/, springmvc servlet将处理原来处理静态资源的映射 -->
31 <servlet-mapping>
32 <servlet-name>springmvc</servlet-name>
33 <url-pattern>/</url-pattern>
34 </servlet-mapping>
35
36 <!-- 浏览器不支持put,delete等method,由该filter将/blog?_method=delete转换为标准的http delete方法 -->
37 <filter>
38 <filter-name>HiddenHttpMethodFilter</filter-name>
39 <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
40 </filter>
41
42 <filter-mapping>
43 <filter-name>HiddenHttpMethodFilter</filter-name>
44 <servlet-name>springmvc</servlet-name>
45 </filter-mapping>
2.webapp/WEB-INF/springmvc-servlet.xml配置,使用如下两个class激活@RequestMapping annotation
2<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/>
3
3.Controller编写
2 * @RequestMapping("/userinfo") 具有层次关系,方法级的将在类一级@RequestMapping之一,
3 * 如下面示例, 访问方法级别的@RequestMapping("/new"),则URL为 /userinfo/new
4 */
5@Controller
6@RequestMapping("/userinfo")
7public class UserInfoController extends BaseSpringController{
8 //默认多列排序,example: username desc,createTime asc
9 protected static final String DEFAULT_SORT_COLUMNS = null;
10
11 private UserInfoManager userInfoManager;
12
13 private final String LIST_ACTION = "redirect:/userinfo";
14
15 /**
16 * 通过spring自动注入
17 **/
18 public void setUserInfoManager(UserInfoManager manager) {
19 this.userInfoManager = manager;
20 }
21
22 /** 列表 */
23 @RequestMapping
24 public ModelAndView index(HttpServletRequest request,HttpServletResponse response,UserInfo userInfo) {
25 PageRequest<Map> pageRequest = newPageRequest(request,DEFAULT_SORT_COLUMNS);
26 //pageRequest.getFilters(); //add custom filters
27
28 Page page = this.userInfoManager.findByPageRequest(pageRequest);
29 savePage(page,pageRequest,request);
30 return new ModelAndView("/userinfo/list","userInfo",userInfo);
31 }
32
33 /** 进入新增 */
34 @RequestMapping(value="/new")
35 public ModelAndView _new(HttpServletRequest request,HttpServletResponse response,UserInfo userInfo) throws Exception {
36 return new ModelAndView("/userinfo/new","userInfo",userInfo);
37 }
38
39 /** 显示 */
40 @RequestMapping(value="/{id}")
41 public ModelAndView show(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) throws Exception {
42 UserInfo userInfo = (UserInfo)userInfoManager.getById(id);
43 return new ModelAndView("/userinfo/show","userInfo",userInfo);
44 }
45
46 /** 编辑 */
47 @RequestMapping(value="/{id}/edit")
48 public ModelAndView edit(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) throws Exception {
49 UserInfo userInfo = (UserInfo)userInfoManager.getById(id);
50 return new ModelAndView("/userinfo/edit","userInfo",userInfo);
51 }
52
53 /** 保存新增 */
54 @RequestMapping(method=RequestMethod.POST)
55 public ModelAndView create(HttpServletRequest request,HttpServletResponse response,UserInfo userInfo) throws Exception {
56 userInfoManager.save(userInfo);
57 return new ModelAndView(LIST_ACTION);
58 }
59
60 /** 保存更新 */
61 @RequestMapping(value="/{id}",method=RequestMethod.PUT)
62 public ModelAndView update(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) throws Exception {
63 UserInfo userInfo = (UserInfo)userInfoManager.getById(id);
64 bind(request,userInfo);
65 userInfoManager.update(userInfo);
66 return new ModelAndView(LIST_ACTION);
67 }
68
69 /** 删除 */
70 @RequestMapping(value="/{id}",method=RequestMethod.DELETE)
71 public ModelAndView delete(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) {
72 userInfoManager.removeById(id);
73 return new ModelAndView(LIST_ACTION);
74 }
75
76 /** 批量删除 */
77 @RequestMapping(method=RequestMethod.DELETE)
78 public ModelAndView batchDelete(HttpServletRequest request,HttpServletResponse response) {
79 String[] items = request.getParameterValues("items");
80 for(int i = 0; i < items.length; i++) {
81 java.lang.Long id = new java.lang.Long(items[i]);
82 userInfoManager.removeById(id);
83 }
84 return new ModelAndView(LIST_ACTION);
85 }
86
87}
88
2 /userinfo/new => _new()
3 /userinfo/{id} => show()
4 /userinfo/{id}/edit => edit()
5 /userinfo POST => create()
6 /userinfo/{id} PUT => update()
7 /userinfo/{id} DELETE => delete()
8 /userinfo DELETE => batchDelete()
9
注(不使用 /userinfo/add => add() 方法是由于add这个方法会被maxthon浏览器当做广告链接过滤掉,因为包含ad字符)
4.jsp 编写
2</form:form>
生成的html内容如下, 生成一个hidden的_method=put,并于web.xml中的HiddenHttpMethodFilter配合使用,在服务端将post请求改为put请求
2 <input type="hidden" name="_method" value="put"/>
3</form>
另外一种方法是你可以使用ajax发送put,delete请求.
5.静态资源的URL重写
如上我们描述,现因为将default servlet映射至/static/的子目录,现我们访问静态资源将会带一个/static/前缀.
如 /foo.gif, 现在访问该文件将是 /static/foo.gif.
那如何避免这个前缀呢,那就是应用URL rewrite,现我们使用 http://tuckey.org/urlrewrite/, 重写规则如下
2 <!-- 访问jsp及jspx将不rewrite url,其它.js,.css,.gif等将重写,如 /foo.gif => /static/foo.gif -->
3 <rule>
4 <condition operator="notequal" next="and" type="request-uri">.*.jsp</condition>
5 <condition operator="notequal" next="and" type="request-uri">.*.jspx</condition>
6 <from>^(/.*\..*)$</from>
7 <to>/static$1</to>
8 </rule>
9</urlrewrite>
----------------------------------------------------
1.1 加包
1.2 web.xml
<servlet>
<servlet-name>springMVC</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springMVC</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
abc
1.3 建springMVC-servlet.xml(注:spring默认要求建立在WEB-INF目录下,并且名称为servlet-name_servlet.xml
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<context:component-scan base-package="com.wdl.cn.controllers" />
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/page/"/>
<property name="suffix" value=".jsp"/>
</bean>
</beans>
1.4 StartController.java
package com.wdl.cn.controllers;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class StartController {
@RequestMapping(value="/start")
public String start(){
System.out.println("start method invoked...");
return "start";
}
}
1.5 新建 WEB-INF/page/start.jsp
1.6 访问:http://localhost:8080/springMVC_001/start.do
总结:本例子搭建一个简单的spingmvc实例,通过本例学习springMVC最简单的流程及搭建元素。
第二讲 灵活指定springmvc映射文件及路径
更多情况下,对于第一讲中的springMVC-servlet.xml 文件,我们并不想去放在WEB-INF,或者说我们可能在一个项目中并不是只有这一个文件,所以本节我们来讲述如何灵活配置此文件及文件名。
2.1 修改web.xml
<servlet>
<servlet-name>springMVC</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath*:/com/wdl/cn/config/mvc/*.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springMVC</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
2.2 将WEB-INF下面的springMVC-servlet.xml 移动到com.wdl.cn.config.mvc包下并将其修改名称为springMVC-first.xml
2.3 测试原来的路径 : http://localhost:8080/springMVC_002/start.do
总结:本讲主要学习了如何灵活配置springMVC配置文件。下节将重点讲述@RequestMapping的使用。
第三讲 springMVC_003 @RequestMapping的使用
3.1 @RequestMapping 使用位置
a.使用于方法,此方法则可以被请求访问;
b.使用于类,则可以将请求分(又叫分路径,分模块)包处理
3.2 将controller类上加@RequestMapping,修改StartController.java
package com.wdl.cn.controllers;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
@RequestMapping(value="/test")
public class StartController {
@RequestMapping(value="/start")
public String start(){
System.out.println("start method invoked...");
return "start";
}
}
3.3 访问:http://localhost:8080/springMVC_003/test/start.do ,由此可见,可以通过在类上加@RequestMapping将请求分路径。
3.4 @RequestMapping 参数详解
a.value表示访问的路径
b.method 表示请求的方式 GET | POST
step1:修改StartController.java
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
@Controller
@RequestMapping(value="/test")
public class StartController {
@RequestMapping(value="/start",method=RequestMethod.GET)
public String start(){
System.out.println("start method invoked...");
return "start";
}
@RequestMapping(value="/start",method=RequestMethod.POST)
public String start2(){
System.out.println("start2 method invoked...");
return "start";
}
}
step2:修改start.jsp模拟POST请求
3.5 访问http://localhost:8080/springMVC_003/test/start.do,接着转到start.jsp页面,接着点击页面的中按钮,发送POST请求,则可以看出不同的请求方式可以调用不同的方法。
3.6 参数传递(常用参数传递,restful风格参数传递)
a.httpservletreqeust方式参数传递
step1:修改StartController.java
package com.wdl.cn.controllers;
import javax.servlet.http.HttpServletRequest;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
@Controller
@RequestMapping(value="/test")
public class StartController {
@RequestMapping(value="/start",method=RequestMethod.GET)
public String start(HttpServletRequest request){
System.out.println("start method invoked...");
String name = request.getParameter("name");
int age = Integer.parseInt(request.getParameter("age"));
System.out.println("name=" + name + " age = " + age);
return "start";
}
@RequestMapping(value="/start",method=RequestMethod.POST)
public String start2(){
System.out.println("start2 method invoked...");
return "start";
}
}
step2:访问:http://localhost:8080/springMVC_003/test/start.do?name=zhangsan&age=45
b.restfull风格参数传递
step1:修改StartController.java
package com.wdl.cn.controllers;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
@Controller
@RequestMapping(value="/test")
public class StartController {
@RequestMapping(value="/start/{name}/{age}",method=RequestMethod.GET)
public String start(@PathVariable("name") String name,@PathVariable("age") int age){
System.out.println("start method invoked...");
System.out.println("name="+name+" age="+age);
return "start";
}
@RequestMapping(value="/start",method=RequestMethod.POST)
public String start2(){
System.out.println("start2 method invoked...");
return "start";
}
}
step2:访问时,将参数值加入请求路径 http://localhost:8080/springMVC_003/test/start/zhangsan/45.do
总结:本讲主要讲述请求参数传递,主要掌握HttpServletRequest方式与restfull风格参数传递,下讲主要讲述form表单提交
第四讲 form表单提交
使用struts2后,我们习惯将form表单的数据封装成一个对象,这也是面向对象编程的一个思维,本节讲述form表单提交。
具体代码见UserController.java
package com.wdl.cn.controllers;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.servlet.http.HttpSession;
import org.springframework.beans.propertyeditors.CustomDateEditor;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;
import com.wdl.cn.entity.User;
@Controller
@RequestMapping(value="/form")
public class UserController {
@RequestMapping(value="/add",method=RequestMethod.GET)
public String toUserAddPage(){
System.out.println("toUserAddPage method invoked...");
return "useradd";
}
@RequestMapping(value="/add",method=RequestMethod.POST)
public ModelAndView addUser(HttpSession session,User user){
System.out.println("addUser method invoked...");
System.out.println(user);
ModelAndView mav = new ModelAndView();
session.setAttribute("abc", user);
mav.setViewName("redirect:/form/add.do");
mav.addObject("abc", user);
//return "useradd";
return mav;
}
@InitBinder
public void initBinder(WebDataBinder binder){
binder.registerCustomEditor(Date.class, new CustomDateEditor(new SimpleDateFormat("yyyy-MM-dd"), false));
}
}
注:addUser方法中参数User则是接收请求发过来的参数;initBinder方法则是用来绑定用户提交的数据,前台提交过来的日期,在这里后面并不知情,则由这个方法来处理。
总结:本讲主要讲述如何来提交表单数据,并将其封装成一个对象。
第五节 一个Controller处理多个请求
很多情况下,我们都想把有关联的请求放在一个controller中,比如,对于一个用户的增删改查,都可以放在一个controller类中。对于springMVC注解的方式有两种方式可以实现。
1.一个controller类中每个处理请求的方法的@requestMapping的param中可以带参数,比如:@RequestMapping(param="method=method1"),在类级别的@RequestMapping上面指定请求路径。
package com.wdl.cn.controllers;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
@Controller
@RequestMapping(value="/manyRequest")
public class ReceiveManyRequestController {
@RequestMapping(params="method=method1")
public ModelAndView methodOne(){
System.out.println("method methodOne invoked...");
ModelAndView mav = new ModelAndView("ReceiveManyRequest");
mav.addObject("msg", "请求第一个方法");
return mav;
}
@RequestMapping(params="method=method2")
public ModelAndView methodTwo(){
System.out.println("method methodTwo invoked...");
ModelAndView mav = new ModelAndView("ReceiveManyRequest");
mav.addObject("msg", "请求第二个方法");
return mav;
}
}
2.每个接收请求的方法的@RequestMapping的value中指定请求路径,看ReceveManyRequestController2.java
package com.wdl.cn.controllers;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
@Controller
@RequestMapping(value="/manyRequest")
public class ReceiveManyRequestController2 {
@RequestMapping(value="/request1")
public ModelAndView methodOne(){
System.out.println("method methodOne invoked...");
ModelAndView mav = new ModelAndView("ReceiveManyRequest");
mav.addObject("msg", "请求第一个方法");
return mav;
}
@RequestMapping(value="/request2")
public ModelAndView methodTwo(){
System.out.println("method methodTwo invoked...");
ModelAndView mav = new ModelAndView("ReceiveManyRequest");
mav.addObject("msg", "请求第二个方法");
return mav;
}
}
这里访问WEB-INF目录下的页面,这个还不知道有没有类似struts2那样的通配符来可以访问不同的action,不同的method,不同的页面,用户则很爽,有的话求告知,而且我还有一个问题就是配置了如下的配置,但却访问不到静态资源,望解答!!-----访问路径:http://localhost:8080/Springmvc3/images/4.jpg
好了,其他不说了,看如下:
配置视图解析器
package com.tgb.controller; import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod; import com.tgb.entity.User; @Controller
@RequestMapping("/test")
//这里也可以写成@RequestMapping("/test.do")也可以不写,因为在web.xml中配置了*.do
public class TestController { @RequestMapping(params="method=addUser")
public String addUser(User user){
System.out.println("dddddddddd");
return "success";
} @RequestMapping(value="/test0")//默认为get方式
public String test0(){
System.out.println("访问路径:test/test0.do");
return "success";
} @RequestMapping(value="/test1",method=RequestMethod.POST)
public String test1(String sex){
System.out.println(sex);
System.out.println("访问路径为:test/test1.do,而且是get方式______"+sex);
return "success";
} @RequestMapping(value="/test2",method=RequestMethod.GET,params="param=test2")
public String test2(){
System.out.println("访问路径为:test/test1.do?param=test2,而且是get方式");
return "success";
} //REST风格的参数
@RequestMapping(value="/test3/{name}")
public String test3(@PathVariable String name){//形参和接收参数的名称一致
System.out.println(name);
System.out.println("访问路径为:test/test3/zhangsan.do");
System.out.println("看这里的访问路径,直接就将‘zhangsan’这个参数值就传递给了@RequestMapping(value=\"/test3/{name}\")中的name参数名,可随意命名参数名称,");
return "success";
} @RequestMapping(value="/test5/{name}")
public String test5(@PathVariable("name")String rename){//形参和接收参数的名称不一致
System.out.println(rename);
System.out.println("访问路径为:test/test5/zhangsan.do");
System.out.println("看这里的访问路径,直接就将‘zhangsan’这个参数值就传递给了@RequestMapping(value=\"/test5/{name}\")中的name参数名,可随意命名参数名称," +
"然后后面的@PathVariable(\"name\")中的name名称要和上面的那个name保持一致,然后把此name绑定到形参rename");
return "success";
} @RequestMapping(value="/test4/{sex}/{sno}")
//这里我写成@RequestMapping(value="test4/{sex}/{sno}")也是可以滴
public String test4(@PathVariable("sex")String sex,@PathVariable("sno")String sno){
System.out.println(sex);
System.err.println(sno);
System.out.println("访问路径:test/test4/male/10506.do");
return "success";
} //支持正则
@RequestMapping(value="/test6/{textualPart:[a-z-]+}.{numericPart:[\\d]+}")
public String test6(@PathVariable String textualPart,@PathVariable String numericPart){
System.out.println(textualPart);//输出sometxt
System.out.println(numericPart);//输出123
System.out.println("访问路径:test/test6/sometxt.123.do");
return "success";
} //访问WEB-INF下的views文件中的不同目录的页面,这里访问的是user目录下的,不知道其他有什么好的办法没
@RequestMapping(value="/test7")
public String test7(){
System.out.println("访问路径:test/test7.do");
return "user/success";
} }