[SpringMVC小练习]使用全注解开发实现一个RESTFUL风格的简单CRUD案例

2023-09-27 19:50:04

案例简介：尽量将SpringMVC的功能进行实现，来开发一个crud案例

未使用数据库而是将数据存入集合中（主要为了连续springmvc的技术而其他从简）

使用到的技术：Spring，SpringMVC，maven等

前端技术：一点点html，一点点vue，一点点thymeleaf实现一个简单的框架

准备

0.配值maven

1.创建前端的页面

2.创建dao（以具体的类代表数据库存储数据）

3.创建实体类对象（bean）

4.创建webinit作为web工程的初始化类，代替web.xml

5.创建webConfig，代替SpringMVC.xml

6.创建springConfig，作为配置类

7.创建interceptor拦截器（此处并没有用途，只是为了练习）

8.创建controller

简单的页面展示，具有完整的添加，删除，修改，查询功能

首页，点击可查询所有信息

查询所有信息

添加

修改（有默认信息的回显）

准备

0.配值maven

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.atguigu.mvc</groupId>
    <artifactId>springMVC-annotation</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <dependencies>
        <!-- SpringMVC -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.3.1</version>
        </dependency>
        <!-- 日志 -->
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.3</version>
        </dependency>
        <!-- ServletAPI -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>
        <!-- Spring5和Thymeleaf整合包 -->
        <dependency>
            <groupId>org.thymeleaf</groupId>
            <artifactId>thymeleaf-spring5</artifactId>
            <version>3.0.12.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.12.1</version>
        </dependency>
        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.3.1</version>
        </dependency>
    </dependencies>
</project>

1.创建前端的页面

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<h1>首页 <br></h1>
<h1><a th:href="@{/employee}">查看员工信息</a><br></h1>
</body>
</html>

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>employeeList</title>
</head>
<body>
<table id="dataTable" border="1" cellspacing="0" cellpadding="0" style="text-align: center;">
    <tr>
        <th colspan="5">Employee Info</th>
    </tr>
    <tr>
        <th>id</th>
        <th>lastName</th>
        <th>email</th>
        <th>gender</th>
        <th>options(<a th:href="@{/toAdd}">add</a>)</th>
    </tr>
    <tr th:each="employee : ${employeeList}">
        <td th:text="${employee.id}"></td>
        <td th:text="${employee.lastName}"></td>
        <td th:text="${employee.email}"></td>
        <td th:text="${employee.gender}"></td>
        <td>
            <a @click="deleteEmployee" th:href="@{'/employee/'+${employee.id}}">delete</a>
            <a th:href="@{'/employee/'+${employee.id}}">update</a>
        </td>
    </tr>
</table>

<form id="deleteForm" method="post">
    <input type="hidden" name="_method" value="delete">
</form>

<script type="text/javascript" th:src="@{/static/js/vue.js}"></script>
<script type="text/javascript">
    var vue = new Vue({
        el: "#dataTable",
        methods: {
            deleteEmployee: function (event) {
                //根据id获取表单元素
                var deleteForm = document.getElementById("deleteForm");
                //将触发点击事件的超链接的href属性赋值给表单的action
                deleteForm.action = event.target.href;
                //提交表单
                deleteForm.submit();
                //取消超链接的默认行为
                event.preventDefault();
            }
        }
    });
</script>
</body>
</html>

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form th:action="@{/employee}" method="post">
    lastName:<input type="text" name="lastName"><br>
    email:<input type="text" name="email"><br>
    性别:<input type="radio" name="gender" value="0">male<br>
    <input type="radio" name="gender" value="1">female<br>
    <input type="submit" value="add">
</form>
</body>
</html>

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form th:action="@{/employee}" method="post">
    <input type="hidden" name="_method" value="PUT">
    <input type="hidden" name="id" th:value="${employee.id}">
    lastName:<input type="text" name="lastName" th:value="${employee.lastName}"><br>
    email:<input type="text" name="email" th:value="${employee.email}"><br>
    性别:<input type="radio" name="gender" value="0" th:field="${employee.gender}">male<br>
    <input type="radio" name="gender" value="1" th:field="${employee.gender}">female<br>
    <input type="submit" value="update">
</form>
</body>
</html>

2.创建dao（以具体的类代表数据库存储数据）

@Repository
public class EmployeeDao {

    private static Map<Integer, Employee> employees;

    static {
        employees = new HashMap<>();

        employees.put(1001, new Employee(1001, "E-AA", "aa@163.com", 1));
        employees.put(1002, new Employee(1002, "E-BB", "bb@163.com", 1));
        employees.put(1003, new Employee(1003, "E-CC", "cc@163.com", 0));
        employees.put(1004, new Employee(1004, "E-DD", "dd@163.com", 0));
        employees.put(1005, new Employee(1005, "E-EE", "ee@163.com", 1));
    }

    private static Integer initId = 1006;

    public void save(Employee employee) {
        if (employee.getId() == null) {
            employee.setId(initId++);
        }
        employees.put(employee.getId(), employee);
    }

    public Collection<Employee> getAll() {
        return employees.values();
    }

    public Employee get(Integer id) {
        return employees.get(id);
    }

    public void delete(Integer id) {
        employees.remove(id);
    }
}

3.创建实体类对象（bean）

public class Employee {
    private Integer id;
    private String lastName;
    private String email;
    private Integer gender;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Integer getGender() {
        return gender;
    }

    public void setGender(Integer gender) {
        this.gender = gender;
    }

    public Employee(Integer id, String lastName, String email, Integer gender) {
        super();
        this.id = id;
        this.lastName = lastName;
        this.email = email;
        this.gender = gender;
    }

    public Employee() {
    }
}

4.创建webinit作为web工程的初始化类，代替web.xml

//web工程的初始化类，用来代替web.xml
public class WebInit extends AbstractAnnotationConfigDispatcherServletInitializer {
    /**
     * 指定spring的配置类
     */
    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[]{springConfig.class};
    }

    /**
     * 指定springMVC的配置类
     */
    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class[]{webConfig.class};
    }

    /**
     * 指定DispatcherServlet的映射规则，即url-patton
     */
    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }

    /**
     * 注册过滤器
     */
    @Override
    protected Filter[] getServletFilters() {
        CharacterEncodingFilter characterEncodingFilter = new CharacterEncodingFilter();
        characterEncodingFilter.setEncoding("UTF-8");
        characterEncodingFilter.setForceResponseEncoding(true);
        HiddenHttpMethodFilter hiddenHttpMethodFilter = new HiddenHttpMethodFilter();
        return new Filter[]{characterEncodingFilter, hiddenHttpMethodFilter};
    }
}

5.创建webConfig，代替SpringMVC.xml

@Configuration //标识为配置类
@ComponentScan("mvc") //开启扫描组件
@EnableWebMvc //开启MVC注解驱动
public class webConfig implements WebMvcConfigurer {

    /**
     * 异常处理
     */
    @Override
    public void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> resolvers) {
        SimpleMappingExceptionResolver exceptionResolver = new SimpleMappingExceptionResolver();
        Properties properties = new Properties();
        properties.setProperty("java.lang.ArithmeticException", "error");
        exceptionResolver.setExceptionMappings(properties);
        exceptionResolver.setExceptionAttribute("exception");
        resolvers.add(exceptionResolver);
    }

    /**
     * 文件上传解析器
     */
    @Bean
    public MultipartResolver multipartResolver() {
        CommonsMultipartResolver commonsMultipartResolver = new CommonsMultipartResolver();
        return commonsMultipartResolver;
    }

    /**
     * 相当于view-controller，直接转发到某个页面
     */
    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addViewController("/index").setViewName("index");
    }

    /**
     * 添加拦截器
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        TestInterceptor testInterceptor = new TestInterceptor();
        registry.addInterceptor(testInterceptor).addPathPatterns("/**");//添加拦截路径(拦截所有请求)
    }

    /**
     * 相当于default-servlet-handler，开启对静态资源的访问
     */
    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }

    //配置生成模板解析器
   @Bean
    public ITemplateResolver templateResolver() {
        WebApplicationContext webApplicationContext = ContextLoader.getCurrentWebApplicationContext();
        // ServletContextTemplateResolver需要一个ServletContext作为构造参数，可通过WebApplicationContext 的方法获得
        ServletContextTemplateResolver templateResolver = new ServletContextTemplateResolver(
                webApplicationContext.getServletContext());
        templateResolver.setPrefix("/WEB-INF/templates/");
        templateResolver.setSuffix(".html");
        templateResolver.setCharacterEncoding("UTF-8");
        templateResolver.setTemplateMode(TemplateMode.HTML);
        return templateResolver;
    }

    //生成模板引擎并为模板引擎注入模板解析器
    @Bean
    public SpringTemplateEngine templateEngine(ITemplateResolver templateResolver) {
        SpringTemplateEngine templateEngine = new SpringTemplateEngine();
        templateEngine.setTemplateResolver(templateResolver);
        return templateEngine;
    }

    //生成视图解析器并未解析器注入模板引擎
    @Bean
    public ViewResolver viewResolver(SpringTemplateEngine templateEngine) {
        ThymeleafViewResolver viewResolver = new ThymeleafViewResolver();
        viewResolver.setCharacterEncoding("UTF-8");
        viewResolver.setTemplateEngine(templateEngine);
        return viewResolver;
    }
}

6.创建springConfig，作为配置类

@Configuration //声明为配置类
@ComponentScan(basePackages = "mvc.controller")
public class springConfig {
}

7.创建interceptor拦截器（此处并没有用途，只是为了练习）

public class TestInterceptor implements HandlerInterceptor{
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
    }
}

8.创建controller

@Controller
public class TestController {
    //required=false
    @Autowired(required=false)
    private EmployeeDao employeeDao;

    @RequestMapping("/")
    public String index() {
        return "index";
    }

    @RequestMapping("/toAdd")
    public String add() {
        return "employee_add";
    }

    /**
     * 返回所有员工信息
     */
    @RequestMapping(value = "/employee", method = RequestMethod.GET)
    public ModelAndView getAllEmployee() {
        ModelAndView modelAndView = new ModelAndView();
        Collection<Employee> employeeList = employeeDao.getAll();
        modelAndView.addObject("employeeList", employeeList);
        modelAndView.setViewName("employee_list");
        return modelAndView;
    }

    /**
     * 根据指定id删除员工信息
     */
    @RequestMapping(value = "/employee/{id}", method = RequestMethod.DELETE)
    public String deleteEmployee(@PathVariable("id") Integer id) {
        employeeDao.delete(id);
        return "redirect:/employee"; //请求重定向
    }

    /**
     * 添加员工信息
     */
    @RequestMapping(value = "employee", method = RequestMethod.POST)
    public String addEmployee(Employee employee) {
        employeeDao.save(employee);
        return "redirect:/employee";
    }

    /**
     * 根据id查询员工信息
     */
    @RequestMapping(value = "/employee/{id}", method = RequestMethod.GET)
    public String getEmployeeById(@PathVariable("id") Integer id, Model model) {
        Employee employee = employeeDao.get(id);
        model.addAttribute("employee", employee);
        return "employee_update";
    }

    /**
     * 修改员工信息
     */
    @RequestMapping(value = "/employee", method = RequestMethod.PUT)
    public String update(Employee employee) {
        employeeDao.save(employee);
        return "redirect:/employee";
    }
}

这样就实现了一个简单的RESTFUL风格的crud案例

码农公寓

准备

0.配值maven

1.创建前端的页面

2.创建dao（以具体的类代表数据库存储数据）

3.创建实体类对象（bean）

4.创建webinit作为web工程的初始化类，代替web.xml

5.创建webConfig，代替SpringMVC.xml

6.创建springConfig，作为配置类

7.创建interceptor拦截器（此处并没有用途，只是为了练习）

8.创建controller

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