1. SpringMVC简单使用
1.1 引入SpringMVC依赖
pom.xml
<?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>org.example</groupId>
<artifactId>maven_test</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<name>maven_test Maven Webapp</name>
<!-- FIXME change it to the project's website -->
<url>http://www.example.com</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
<spring.version>4.2.6.RELEASE</spring.version>
</properties>
<dependencies>
<!-- junit是自动生成的 -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
<!-- spring-context -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.2.5.RELEASE</version>
</dependency>
<!-- web.xml里的DispatcherServlet需要用到 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
<!-- 与tomcat的依赖冲突,需要加上scope -->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>javax.servlet.jsp-api</artifactId>
<version>2.3.3</version>
<!-- 与tomcat的依赖冲突,需要加上scope -->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
</dependencies>
<!-- 下面是自动生成的 -->
<build>
<finalName>maven_test</finalName>
<pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
<plugins>
<plugin>
<artifactId>maven-clean-plugin</artifactId>
<version>3.1.0</version>
</plugin>
<!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging -->
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>3.0.2</version>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.22.1</version>
</plugin>
<plugin>
<artifactId>maven-war-plugin</artifactId>
<version>3.2.2</version>
</plugin>
<plugin>
<artifactId>maven-install-plugin</artifactId>
<version>2.5.2</version>
</plugin>
<plugin>
<artifactId>maven-deploy-plugin</artifactId>
<version>2.8.2</version>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
在上面的依赖中,需要对servlet-api和jsp-api加上scope,因为tomcat的依赖包含这两个,如果不加,运行时会报错。这个scope 只能作用在编译和测试时,同时没有传递性。
1.2 创建mvc-dispatcher-servlet.xml
<!--这里的配置了xmlns:context,在xsi:schemaLocation中就要配置对应的spring-context.xsd-->
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!-- 扫描的目录-->
<context:component-scan base-package="com.crystallake.demo"/>
<!-- 静态资源配置-->
<mvc:default-servlet-handler/>
<!-- 启用注解-->
<mvc:annotation-driven/>
<bean id="jspViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
<property name="prefix" value="/WEB-INF/pages/"/>
<property name="suffix" value=".jsp"/>
</bean>
</beans>
InternalResourceViewResolver会将视图名解析为JSP文 件。另外,如果在你的JSP页面中使用了JSP标准标签库 (JavaServer Pages Standard Tag Library,JSTL)的 话,InternalResourceViewResolver能够将视图名解析为 JstlView形式的JSP文件,从而将JSTL本地化和资源bundle变量暴 露给JSTL的格式化(formatting)和信息(message)标签。
- prefix:前缀,请求的接口带上/WEB-INF/pages/前缀
- suffix:后缀,请求的接口后面带上.jsp
这两个参数来自于InternalResourceViewResolver的父类UrlBasedViewResolver,如图所示:
1.3 配置web.xml
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app
xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
version="3.1">
<display-name>Archetype Created Web Application</display-name>
<servlet>
<!-- 这里的名称要和servlet-mapping里面的名称一致-->
<servlet-name>mvc-dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:mvc-dispatcher-servlet.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<!-- 这里的名称要和servlet里面的名称一致-->
<servlet-name>mvc-dispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
- 如果不写任何参数配置(也就是没有servlet和servlet-mapping配置),默认的是在/WEB-INF/applicationContext.xml。
- 如果指定了要加载的文件(就是配置了init-param),则会去加载相应的xml,而不会去加载/WEB-INF/下的applicationContext.xml。如果没有指定的话,默认会去/WEB-INF/下加载applicationContext.xml。
- 如果想要自定义文件名,需要在web.xml中加入contextConfigLocation这个context参数并指定classpath,这里默认加载resources文件夹下的xml文件
1.4 MainController创建
package com.crystallake.demo;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
@Controller
public class MainController {
@RequestMapping(value = "/",method = RequestMethod.GET)
public String test(){
return "main";
}
}
注意,webapp下的index.jsp要删除,不然它默认加载该jsp页面。
maven->clean->package->run
http://localhost:8083/maven_test_war_exploded/
是baseUrl
,因为在mvc-dispatcher-servlet.xml
里面配置了前缀和后缀,所以它默认会加上前缀/WEB-INF/pages/
,然后调用MainController
的test
方法返回main
,然后自动加上后缀.jsp
,所以最终的请求为
http://localhost:8083/maven_test_war_exploded/WEB-INF/pages/main.jsp