SpringMVC適配器

適配器Adapter【Action實現什麼接口】
Action實現Controller接口
org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter

目錄結構

操作流程

pom.xml

<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.springapp</groupId>
    <artifactId>SpringMVC003</artifactId>
    <packaging>war</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>SpringMVC003</name>

    <properties>
        <spring.version>3.2.0.RELEASE</spring.version>
    </properties>

    <dependencies>
        <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>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.5</version>
        </dependency>

        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.1</version>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.8.2</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <finalName>SpringMVC003</finalName>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-surefire-plugin</artifactId>
                <configuration>
                    <includes>
                        <include>**/*Tests.java</include>
                    </includes>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

web.xml

<web-app version="2.4"
         xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

    <display-name>Spring MVC Application</display-name>

    <!--註冊SpringMVC的核心控制器-->
    <servlet>
        <servlet-name>mvc-dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

        <!--通知DispatcherServlet去指定的目錄下加載springmvc.xml-->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value >WEB-INF/mvc-dispatcher-servlet.xml</param-value>
        </init-param>

    </servlet>

    <servlet-mapping>
        <servlet-name>mvc-dispatcher</servlet-name>
        <url-pattern>*.action</url-pattern>
    </servlet-mapping>

    <servlet-mapping>
        <servlet-name>mvc-dispatcher</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <welcome-file-list>
        <welcome-file>emp.jsp</welcome-file>
    </welcome-file-list>

</web-app>

mvc-dispatcher-servlet.xml

<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"
       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">

    <!--控制器Action-->
    <bean name="/add.action" class="com.springapp.mvc.EmpAction"></bean>


    <!--映射器（BeanNameUrlHandlerMapping表示將bean標籤的name屬性當做URL請求） 可省略-->
    <bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"></bean>

    <!--
        適配器
        SimpleControllerHandlerAdapter表示用於尋找實現了Controller接口的Action類
    -->
    <bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"></bean>

    <!--
        視圖解析器
     -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/pages/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

</beans>

emp.jsp

<%@ page language="java" pageEncoding="UTF-8" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
    <head>
        <title>適配器</title>
    </head>

    <body>
       <form action="${pageContext.request.contextPath}/add.action" method="POST">
           員工姓名：<input type="text" name="username" />
           <input type="submit" value="提交">
       </form>
    </body>
</html>

EmpAction.java

package com.springapp.mvc;

import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 *
 * 控制器是實現Controller接口的類
 * Created by liguodong on 2015/11/17.
 */
public class EmpAction implements Controller {
    @Override
    public ModelAndView handleRequest(HttpServletRequest request,
                                      HttpServletResponse response)
            throws Exception {
        //設置編碼方式(POST方式)
        request.setCharacterEncoding("UTF-8");

        //獲取員工姓名
        String username = request.getParameter("username");
        //顯示
        System.out.println("員工姓名：" + username);
        //將員工姓名封裝到ModelAndView對象中去

        ModelAndView modelAndView = new ModelAndView();
        modelAndView.addObject("massage",username);

        //封裝路徑到ModelAndView
        modelAndView.setViewName("hello");
        //modelAndView.setViewName("/WEB-INF/pages/hello.jsp");

        return modelAndView;
    }
}

/**
 *  1、Action類實現Controller類接口，帶來了代碼耦合
 *  2、如果參數過多，實現了Controller接口的Action收集起來不爽
 */

hello.jsp

<%@ page language="java" pageEncoding="UTF-8" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<body>
hello.jsp<br/>
成功<br/>
request:${requestScope.massage}<br/>
</body>
</html>

運行結果：