Spring in Action（五）：基于Java Config的SpringMVC

1、搭建SpringMVC项目

可参考搭建Spring项目教程：http://blog.csdn.net/lom9357bye/article/details/72796668

pom文件如下

<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.learning</groupId>
    <artifactId>springmvc-learning</artifactId>
    <packaging>war</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>springmvc-learning Maven Webapp</name>
    <url>http://maven.apache.org</url>
    <dependencies>

        <!--使用单元测试所需jar包-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>4.3.8.RELEASE</version>
        </dependency>

        <!--spring相关包-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>4.3.8.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>4.3.8.RELEASE</version>
        </dependency>


        <!--jstl-->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>
        <!--servlet-api-->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
        </dependency>

    </dependencies>
    <build>
        <finalName>springmvc-learning</finalName>
    </build>
</project>

2、由于使用java文件进行配置，所以可以将web.xml清空

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
          http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
         version="3.0">


</web-app>

3、在java目录下创建包，并创建一个RootConfig和WebConfig类

4、创建一个初始化配置的类SpittrWebAppInitializer，并继承AbstractAnnotationConfigDispatcherServletInitializer

package com.learn.config;

import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

/**
 * 继承AbstractAnnotationConfigDispatcherServletInitializer的类会自动配置DispatcherServlet和spring应用上下文
 * 1.在Servlet 3.0中，容器会在类路径中查找实现ServletContainerInitializer接口的类，并用它来配置Servlet容器
 * 2.Spring中有ServletContainerInitializer接口的实现，名为SpringServletContainerInitializer，这个类又会查找实现WebApplicationInitializer的类并将配置任务交给它们来完成
 * 3.AbstractAnnotationConfigDispatcherServletInitializer是WebApplicationInitializer的实现类，而我们的配置类SpittrWebAppInitializer又继承了它
 * 4.因此可以使用我们的配置类来配置Servlet上下文
 * spring in action
 */
public class SpittrWebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer{
    protected Class<?>[] getRootConfigClasses() {
        return new Class[]{RootConfig.class};
    }

    protected Class<?>[] getServletConfigClasses() {
        return new Class[]{WebConfig.class};
    }

    protected String[] getServletMappings() {
        //将DispatcherServlet映射到"/",相当于web.xml中配置的servlet-mapping
        return new String[]{"/"};
    }
}

5、WebConfig类中配置视图解析器

package com.learn.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;


@Configuration//将类作为配置配
@EnableWebMvc//启用SpringMVC
@ComponentScan("com.learn.controller")//启用组件扫描
public class WebConfig extends WebMvcConfigurerAdapter{

    //注册一个ViewResolver视图解析器bean,配置JSP视图解析器
    @Bean
    public ViewResolver viewResolver(){
        InternalResourceViewResolver resolver=new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/views/");
        resolver.setSuffix(".jsp");
        resolver.setExposeContextBeansAsAttributes(true);
        return resolver;
    }

    //配置静态资源的处理，要求DispathServlet将对静态资源的请求转发到Servlet容器中默认的servlet
    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer){
        configurer.enable();
    }
}

6、RootConfig

package com.learn.config;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.ComponentScan.Filter;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.FilterType;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;


@Configuration
@ComponentScan(basePackages = "com.learn",excludeFilters = {
        @Filter(type=FilterType.ANNOTATION,value= EnableWebMvc.class)
})
public class RootConfig {
}

7、现在springmvc项目所需要的基本配置已经配置完毕，接下来创建一个HelloController

package com.learn.controller;

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


@Controller//将此类作为控制器
public class HelloController {

    @RequestMapping(value="/hello")//设置请求映射，处理对"/hello"的请求
    public String hello(){
        return "hello";//视图名为hello，视图解析器会寻找WEB-INF/views/hello.jsp
    }
}

8、在WEB-INF/下建一个views文件夹，并在views目录下建一个hello.jsp

<html>
<body>
<h2>hello spring mvc</h2>
</body>
</html>

9、启动Tomcat

输入http://localhost:8080/hello进行测试

注：在配置Tomcat时，ApplicationContext设为了/,因此可以直接通过http://localhost:8080/访问项目，而不需要带上项目名称

10、使用mock进行单元测试

package com.learn.controller;

import org.junit.Test;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
import org.springframework.test.web.servlet.result.MockMvcResultMatchers;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;
import org.springframework.web.servlet.view.InternalResourceView;


public class HelloControllerTest {

    @Test
    public void helloTest() throws Exception{
        HelloController controller=new HelloController();
        MockMvc mockMvc= MockMvcBuilders.standaloneSetup(controller).setSingleView(new InternalResourceView("/WEB-INF/views/hello.jsp")).build();
        mockMvc.perform(MockMvcRequestBuilders.get("/hello")).andExpect(MockMvcResultMatchers.view().name("hello"));
    }
}

参考：Spring in Action