首先了解下SpringMVC是什么
1.SpringMVC是一种思想,也是当前最优秀的MVC框架,自从Spring 2.5版本发布后,由于支持注解配置,易用性有了大幅度的提高。Spring 3.0更加完善,实现了对Struts 2的超越。现在越来越多的开发团队选择了Spring MVC。
Spring Web MVC是一种基于Java的实现了Web MVC设计模式的请求驱动类型的轻量级Web框架,即使用了MVC架构模式的思想,将web层进行职责解耦,基于请求驱动指的就是使用请求-响应模型,框架的目的就是帮助我们简化开发,Spring Web MVC也是要简化我们日常Web开发的。
简单来说:分层,解耦,简化开发。
2.Spring3 MVC的优点:
Spring3 MVC使用简单,学习成本低。学习难度小于Struts2,Struts2用不上的多余功能太多。呵呵,当然这不是决定因素。
Spring3 MVC很容易就可以写出性能优秀的程序,Struts2要处处小心才可以写出性能优秀的程序(指MVC部分)
Spring3 MVC的灵活是你无法想像的,Spring框架的扩展性有口皆碑,Spring3 MVC当然也不会落后,不会因使用了MVC框架而感到有任何的限制。
核心原理
1、 用户发送请求给服务器。url:user
2、 服务器收到请求。发现Dispatchservlet可以处理。于是调用DispatchServlet。
3、 DispatchServlet内部,通过HandleMapping检查这个url有没有对应的Controller。如果有,则告诉DispatchServlet调用HandleAdapter去执行相应的Controller。
4、 Control开始执行
5、 Controller执行完毕后,如果返回字符串,则ViewResolver将字符串转化成相应的视图对象;如果返回ModelAndView对象,该对象本身就包含了视图对象信息。
6、 DispatchServlet将执视图对象中的数据,输出给服务器。
7、 服务器将数据输出给客户端
环境搭建
之前创建好的Maven项目:
首先,要在main下创建两个文件夹:java,resources
main---New---Directory
注意:把java文件夹设为Sources Root
resources文件夹设为Resources Root
准备工作做好,主要步骤:
1、POM.xml中添加相应的依赖
2、在web.xml中配置DispatcherServlet
3、在resource目录中新建Springmvc的配置文件
所需要jar:
<?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.lianwei</groupId>
<artifactId>Test1</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<name>Test1 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>4.2.5.RELEASE</spring-version>
<org.springframework-version>3.2.8.RELEASE</org.springframework-version>
<aspect-version>1.8.7</aspect-version>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>taglibs</groupId>
<artifactId>standard</artifactId>
<version>1.1.2</version>
</dependency>
<!--Spring配置-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</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-context</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-context-support</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-aop</artifactId>
<version>${spring-version}</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>${aspect-version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>${spring-version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${org.springframework-version}</version>
</dependency>
<!-- json包-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.31</version>
</dependency>
<!-- https://mvnrepository.com/artifact/log4j/log4j -->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
</dependencies>
<build>
<finalName>Test1</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>3.0.0</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>3.7.0</version>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.20.1</version>
</plugin>
<plugin>
<artifactId>maven-war-plugin</artifactId>
<version>3.2.0</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>
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>
<!-- 配置springmvc的核心servlet-->
<servlet>
<servlet-name>springMVC</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext-mvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<filter>
<filter-name>characterEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<init-param>
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>characterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<servlet-mapping>
<servlet-name>springMVC</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<!-- 部署applicationContext的xml文件
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</context-param> -->
<!-- ContextLoaderListener的作用就是启动Web容器时,自动装配ApplicationContext的配置信息。 因为它实现了ServletContextListener这个接口,在web.xml配置这个监听器,启动容器时,就会默认执行它实现的方法。-->
<!--
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener> -->
</web-app>
在resources下新建springmvc配置文件
注意:文件名称要和web.xml中配置的核心servlet<init-param>中
<param-value>classpath:applicationContext-mvc.xml</param-value>的名称一致,也就是说由于该处配置的值是applicationContext-mvc.xml,所以配置文件名称应该为applicationContext-mvc.xml,这样,web容器启动时就会找到该配置文件。
applicationContext-mvc.xml
<?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">
<!-- 启用spring mvc 注解 -->
<context:annotation-config />
<!-- 设置使用注解的类所在的包 -->
<context:component-scan base-package="com.controller"></context:component-scan>
<!--fastjson配置-->
<mvc:annotation-driven>
<mvc:message-converters register-defaults="true">
<bean class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">
<property name="supportedMediaTypes">
<list>
<value>text/html;charset=UTF-8</value>
<value>application/json</value>
<value>application/xml;charset=UTF-8</value>
</list>
</property>
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
<!-- 配置视图解析器 ,对转向页面的路径解析。prefix:前缀, suffix:后缀-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/admin/"/>
<property name="suffix" value=".jsp"/>
</bean>
</beans>
测试
java文件夹新建com.controller包,包下新建
TestController.java
package com.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
/**
* Created by Tired on 2018/8/3.
*/
@Controller
@RequestMapping("test")
public class TestController {
@RequestMapping("/index")
public String index()
{
return "index";
}
}
webapp下新增admin文件夹,下新建index.jsp
添加tomcat访问localhost:8080/test/index