Spring MVC4 纯注解配置教程

2022-07-29 14:25:34

阅读本文需要又一定的sping基础，最起码要成功的运行过一个SpringMvc项目。

在传统的Spring项目中，我们要写一堆的XML文件。而这些XML文件格式要求又很严格，很不便于开发。而网上所谓的0配置，并不是纯粹的0配置，还是要写一些xml配置，只是用了几个@Service，@Controller注解而已。

在这里，我讲介绍一种新的配置方式，一行XML代码都不需要，什么web.xml,Application-context.xml，Beans.xml，统统去死吧！

首先建立一个Maven项目，Packageing方式为war，项目结构为标准Maven WebApp结构。

pom文件如下（很多依赖都没用，懒得去掉了）：

<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/maven-v4_0_0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>com.csonezp</groupId>

    <artifactId>springdemo</artifactId>

    <packaging>war</packaging>

    <version>1.0-SNAPSHOT</version>

    <name>dataplatform Maven Webapp</name>

    <url>http://maven.apache.org</url>

    <properties>

        <spring.version>4.0.1.RELEASE</spring.version>

    </properties>

    <dependencies>

        <dependency>

            <groupId>junit</groupId>

            <artifactId>junit</artifactId>

            <version>4.11</version>

        </dependency>

        <!-- Spring dependencies -->

        <dependency>

            <groupId>asm</groupId>

            <artifactId>asm-commons</artifactId>

            <version>2.2.3</version>

        </dependency>

        <dependency>

            <groupId>asm</groupId>

            <artifactId>asm</artifactId>

            <version>2.2.3</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-core</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-web</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-orm</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-jdbc</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-context</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-aop</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-expression</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-test</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-tx</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-webmvc</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>cglib</groupId>

            <artifactId>cglib</artifactId>

            <version>2.2.2</version>

        </dependency>

        <!-- Servlet API, JSTL -->

        <dependency>

            <groupId>javax.servlet</groupId>

            <artifactId>javax.servlet-api</artifactId>

            <version>3.0.1</version>

            <scope>provided</scope>

        </dependency>

        <dependency>

            <groupId>jstl</groupId>

            <artifactId>jstl</artifactId>

            <version>1.2</version>

        </dependency>

        <dependency>

            <groupId>org.codehaus.jackson</groupId>

            <artifactId>jackson-core-asl</artifactId>

            <version>1.8.4</version>

        </dependency>

        <dependency>

            <groupId>org.codehaus.jackson</groupId>

            <artifactId>jackson-mapper-asl</artifactId>

            <version>1.8.4</version>

        </dependency>

        <dependency>

            <groupId>c3p0</groupId>

            <artifactId>c3p0</artifactId>

            <version>0.9.1.2</version>

        </dependency>

        <dependency>

            <groupId>log4j</groupId>

            <artifactId>log4j</artifactId>

            <version>1.2.8</version>

        </dependency>

        <dependency>

            <groupId>org.json</groupId>

            <artifactId>json</artifactId>

            <version>20090211</version>

        </dependency>

        <dependency>

            <groupId>mysql</groupId>

            <artifactId>mysql-connector-java</artifactId>

            <version>5.1.6</version>

        </dependency>

        <dependency>

            <groupId>spy</groupId>

            <artifactId>spymemcached</artifactId>

            <version>2.6</version>

        </dependency>

        <dependency>

            <groupId>org.slf4j</groupId>

            <artifactId>slf4j-api</artifactId>

            <version>1.6.6</version>

        </dependency>

    </dependencies>

    <build>

        <finalName>dataplatform</finalName>

    </build>

</project>

这个时候，就该进行Spring配置了。按传统方式来的话，首先要去web.xml写一堆配置，然后建立个管理beab的Beans.xml，管理spring mvc 的xml，再写一坨一坨Bean。就是先进一点的（也就是很多人说的0配置），也就是自己的业务Bean不用写进xml了，还是很麻烦。

而我这里讲的方式，则是完全不修改任何web.xml代码，不写一行XML代码的方式。

首先，在项目立建立一个Config.java文件：

**

 * Created by zhangpeng on 16-3-22.

 * 取代Beans.xml，纯注解配置各种BEAN

 */

@Configuration

@ComponentScan("com.csonezp")

@EnableWebMvc

public class Config {

    /**

     * jsp视图解析器的bean

     * @return

     */

    @Bean

    public UrlBasedViewResolver setupViewResolver() {

        UrlBasedViewResolver resolver = new UrlBasedViewResolver();

        resolver.setPrefix("/WEB-INF/");

        resolver.setSuffix(".jsp");

        resolver.setViewClass(JstlView.class);

        return resolver;

    }

    /**

     * 配置数据源

     * @return

     */

    @Bean(name = "dataSource")

    public ComboPooledDataSource getDataSource() {

        try {

            ComboPooledDataSource dataSource = new ComboPooledDataSource();

            dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/mfdb");

            dataSource.setDriverClass("com.mysql.jdbc.Driver");

            dataSource.setUser("root");

            dataSource.setPassword("zp1228");

            dataSource.setMaxPoolSize(75);

            return dataSource;

        } catch (Exception e) {

            return null;

        }

    }

}

@Configuration注解就是告诉Spring这个是一个配置文件类，这里配置的Bean要交给Spring去管理。这个就是用来取代Beans.xml这种文件的。

@ComponentScan("com.csonezp")这个注解就是配置包扫描用的，不必多说了

@EnableWebMvc ，启用Spring MVC支持

这里面配置了两个Bean，第一个就是JSP的视图解析器，第二个则是配置了一个数据源。这些都可以对应到XML文件里面去的。找一个传统Spring项目，用xml文件对比着我这个类去看，会对这种配置方式有更深的了解。

下面要建立一个WebInitializer类继承WebApplicationInitializer，在这里添加一个servlet。这一步是用来取代在web.xml中添加servlet的步骤

import org.springframework.web.WebApplicationInitializer;

import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;

import org.springframework.web.servlet.DispatcherServlet;

import javax.servlet.ServletContext;

import javax.servlet.ServletException;

import javax.servlet.ServletRegistration.Dynamic;

public class WebInitializer implements WebApplicationInitializer {

    public void onStartup(ServletContext servletContext) throws ServletException {

        AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();

        ctx.register(Config.class);

        ctx.setServletContext(servletContext);    

        Dynamic servlet = servletContext.addServlet("dispatcher", new DispatcherServlet(ctx));

        servlet.addMapping("/");

        servlet.setLoadOnStartup(1);  

    }  

}

这样就OK啦！让我们写一些代码来测试一下吧！

import org.springframework.stereotype.Service;

/**

 * Created by zhangpeng on 16-3-22.

 */

@Service

public class HelloService {

    public String getHello(String name) {

        return name + ",Hello!";

    }

}

import com.guduo.dataplatform.service.HelloService;

import com.guduo.dataplatform.service.MovieService;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Controller;

import org.springframework.ui.ModelMap;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestParam;

/**

 * Created by zhangpeng on 16-3-22.

 */

@Controller

@RequestMapping("/test")

public class TestController {

    @Autowired

    HelloService helloService;

    @Autowired

    MovieService movieService;

    @RequestMapping("/hello")

    public String sayHello(@RequestParam("name") String name, ModelMap model) {

        model.put("hello", helloService.getHello(name));

        return "hello";

    }

}

一个service，一个controller。

启动项目，在浏览器中输入地址http://localhost:8080/dp/test/hello?name=sss

页面显示sss,Hello!

完工！

额，忘了演示Confgig里配置的bean如何使用了。其实和XML里的一样。这里拿一个DAO做演示吧，这里就注入了我们在config里配置的那个数据源

@Repository

public class MoviePlayIncDao {

    private DataSource dataSource;

    private JdbcTemplate jdbcTemplateObject;

    @Autowired

    public void setDataSource(DataSource dataSource) {

        this.dataSource = dataSource;

        this.jdbcTemplateObject = new JdbcTemplate(dataSource);

    }

    public List<MoviePlayIncreament> getMoviePlayInc(int movieId) {

        try {

            String SQL = "select * from movieplayincreament where movieid=?";

            List<MoviePlayIncreament> list = jdbcTemplateObject.query(SQL, new MoviePlayIncMapper(), new Object[]{movieId});

            return list;

        } catch (Exception e) {

            return null;

        }

    }

}

码农公寓

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