如何用Java类配置Spring MVC(不通过web.xml和XML方式)

建立普通MAVEN项目配置POM

<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.ghg</groupId>    <artifactId>chart04</artifactId>    <version>0.0.1-SNAPSHOT</version>    <packaging>war</packaging>    <properties>        <!-- generic -->        <java.version>1.7</java.version>        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>        <!-- web jsp -->        <jsp.version>2.2</jsp.version>        <jstl.verison>1.2</jstl.verison>        <servlet.version>3.1.0</servlet.version>        <!--spring -->        <spring-framework.version>4.3.6.RELEASE</spring-framework.version>        <!--logging -->        <logback.version>1.2.1</logback.version>        <slf4j.version>1.7.23</slf4j.version>        <log4j.version>1.2.17</log4j.version>    </properties>    <dependencies>        <!-- javax -->        <dependency>            <groupId>javax</groupId>            <artifactId>javaee-web-api</artifactId>            <version>7.0</version>            <scope>provided</scope>        </dependency>        <!-- spring -->        <dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-context</artifactId>            <version>${spring-framework.version}</version>        </dependency>        <dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-webmvc</artifactId>            <version>${spring-framework.version}</version>        </dependency>        <dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-tx</artifactId>            <version>${spring-framework.version}</version>        </dependency>        <!--other web dependency -->        <dependency>            <groupId>javax.servlet.jsp</groupId>            <artifactId>jsp-api</artifactId>            <version>${jsp.version}</version>            <scope>provided</scope>        </dependency>        <dependency>            <groupId>javax.servlet</groupId>            <artifactId>jstl</artifactId>            <version>${jstl.verison}</version>        </dependency>        <!-- servlet -->        <dependency>            <groupId>javax.servlet</groupId>            <artifactId>javax.servlet-api</artifactId>            <version>${servlet.version}</version>            <scope>provided</scope>        </dependency>        <!-- logging -->        <!-- SLF4J和logback -->        <dependency>            <groupId>org.slf4j</groupId>            <artifactId>slf4j-api</artifactId>            <version>${slf4j.version}</version>        </dependency>        <!-- logback -->        <dependency>            <groupId>ch.qos.logback</groupId>            <artifactId>logback-classic</artifactId>            <version>${logback.version}</version>        </dependency>        <dependency>            <groupId>ch.qos.logback</groupId>            <artifactId>logback-core</artifactId>            <version>${logback.version}</version>        </dependency>        <dependency>            <groupId>ch.qos.logback</groupId>            <artifactId>logback-access</artifactId>            <version>${logback.version}</version>        </dependency>        <dependency>            <groupId>log4j</groupId>            <artifactId>log4j</artifactId>            <version>${log4j.version}</version>        </dependency>        <!-- jackson -->        <dependency>            <groupId>com.fasterxml.jackson.core</groupId>            <artifactId>jackson-databind</artifactId>            <version>2.8.6</version>        </dependency>    </dependencies>    <build>        <finalName>char04</finalName>        <plugins>            <plugin>                <groupId>org.apache.maven.plugins</groupId>                <artifactId>maven-compiler-plugin</artifactId>                <version>3.6.1</version>                <configuration>                    <source>${java.version}</source>                    <target>${java.version}</target>                    <encoding>UTF-8</encoding>                </configuration>            </plugin>            <plugin>                <groupId>org.apache.maven.plugins</groupId>                <artifactId>maven-war-plugin</artifactId>                <version>3.0.0</version>                <configuration>                    <failOnMissingWebXml>false</failOnMissingWebXml>                </configuration>            </plugin>            <!-- <plugin>                <groupId>org.mortbay.jetty</groupId>                <artifactId>jetty-maven-plugin</artifactId>                <version>8.1.14.v20131031</version>                <configuration>                    <scanIntervalSeconds>600</scanIntervalSeconds>                    <scanTargetPatterns>                        <scanTargetPattern>                            <directory>src/main/webapp</directory>                            <includes>                                <include>**/*.xml</include>                                <include>**/*.properties</include>                                <include>**/*.tld</include>                            </includes>                        </scanTargetPattern>                    </scanTargetPatterns>                    <webAppConfig>                        <contextPath>/char04</contextPath>                    </webAppConfig>                    <connectors>                        <connector implementation="org.eclipse.jetty.server.nio.SelectChannelConnector">                            <port>9090</port>                            <maxIdleTime>60000</maxIdleTime>                        </connector>                    </connectors>                </configuration>            </plugin> -->        </plugins>    </build></project>

配置DispatcherServlet. 需要创建一个Web初始化类

MyMVCConfig extends WebMvcConfigurerAdapter 继承WebMvcConfigurerAdapter

package com.ghg.chart04.config;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.ComponentScan;import org.springframework.context.annotation.Configuration;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;import org.springframework.web.servlet.view.JstlView;@Configuration@EnableWebMvc@ComponentScan("com.ghg.chart04.controller")public class MyMVCConfig extends WebMvcConfigurerAdapter {    @Bean    public InternalResourceViewResolver viewResolver() {        InternalResourceViewResolver resolver = new InternalResourceViewResolver();        resolver.setPrefix("/WEB-INF/classes/views");        resolver.setSuffix(".jsp");        resolver.setViewClass(JstlView.class);        resolver.setExposeContextBeansAsAttributes(true);        return resolver;    }    // 配置静态资源的处理    @Override    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {        configurer.enable(); // 对静态资源的请求转发到容器缺省的servlet，而不使用DispatcherServlet    }}

配置启动配置类RootConfig

package com.ghg.chart04.init;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.ghg.chart04"},excludeFilters={@Filter(type=FilterType.ANNOTATION,value=EnableWebMvc.class)})public class RootConfig {}

配置Spring MVC视图解析WebConfig.java, 需要要创建一个类继承自WebMvcConfigurerAdapter

package com.ghg.chart04.init;import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;import com.ghg.chart04.config.MyMVCConfig;public class WebInitializer extends AbstractAnnotationConfigDispatcherServletInitializer  {    @Override    protected Class<?>[] getRootConfigClasses() {        return new Class<?>[] { RootConfig.class }; //启动配置类    }    @Override    protected Class<?>[] getServletConfigClasses() {         return new Class<?>[] { MyMVCConfig.class };        //ָ指定Web配置类    }    @Override    protected String[] getServletMappings() {        return new String[]{"/"};    }}

至此, 传统方式中需要通过web.xml进行配置的东西就已将全部完成有上面三个java类(WebInitializer , RootConfig, MyMVCConfig )完成. 可以开始写Controller和页面代码了

控制器和页面

package com.ghg.chart04.controller;import javax.servlet.http.HttpServletRequest;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;@RestControllerpublic class HelloController {    @RequestMapping(value="/hello")    public Map<String, String> hello(HttpServletRequest request){        Map<String, String> params = new HashMap<String, String>();        params.put("title", "hello");        params.put("result", "中奖了");        return params;    }}

jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"    pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Welcome</title></head><body><pre>Welcome to Spring MVC!</pre></body></html>