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Java web开发（11）SpringMVC使用非注解和注解方式配置映射器和适配器

基本概念

1、前端控制器 DispatcherServlet（不需要程序员开发）
作用接收请求，响应结果，相当于转发器，中央处理器。
有了 DispatcherServlet 减少了其它组件之间的耦合度。

2、处理器映射器 HandlerMapping(不需要程序员开发)
作用：根据请求的 url 查找 Handler


3、处理器适配器 HandlerAdapter
作用：按照特定规则（HandlerAdapter 要求的规则）去执行 Handler


4、处理器 Handler(需要程序员开发)
注意：编写 Handler 时按照 HandlerAdapter 的要求去做，这样适配器才可以去正确执行 Handler


5、视图解析器 View resolver(不需要程序员开发)
作用：进行视图解析，根据逻辑视图名解析成真正的视图（view）


6、视图 View(需要程序员开发 jsp)
View 是一个接口，实现类支持不同的 View 类型（jsp、freemarker、pdf...）

公共部分：

1 建立 Maven Project，使用 Archetype selection，选中 webapp

2. 右键 Build Path->Configure Build Path, 修改 JRE System Library 为 Workspace default JRE

3. 修改 pom.xml 文件，使用 jsp 的话，额外添加 jsp-api

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.0</version>
            <scope>provided</scope>
        </dependency>

 

<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.nothing</groupId>
    <artifactId>Test</artifactId>
    <packaging>war</packaging>
    <version>0.0.1-SNAPSHOT</version>
    <name>Test Maven Webapp</name>
    <url>http://maven.apache.org</url>
    <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>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.0.1</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>4.1.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>4.1.2.RELEASE</version>
        </dependency>
    </dependencies>
    <build>
        <finalName>Test</finalName>
    </build>
</project>
SpringMVC pom.xml 文件

4. 修改 WEB-INF 文件夹下的 web.xml 文件

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>springmvcfirst1208</display-name>

<!-- springmvc 前端控制器 -->
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!-- contextConfigLocation 配置 springmvc 加载的配置文件（配置处理器映射器、适配器等等）
如果不配置 contextConfigLocation，默认加载的是 /WEB-INF/servlet 名称 -serlvet.xml（springmvc-servlet.xml）
-->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc.xml</param-value>
</init-param>
</servlet>


<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>


<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
</web-app>

 5。右键项目，新建 source folder 名为 config，然后在其中建立 springmvc.xml 文件来配置

先输入

<?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:tx="http://www.springframework.org/schema/tx" 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/tx 
       http://www.springframework.org/schema/tx/spring-tx.xsd
          http://www.springframework.org/schema/mvc
       http://www.springframework.org/schema/mvc/spring-mvc.xsd">

</beans>

6.

在 WEB-INF 目录下 建立 view 目录，display.jsp

内容如下

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt"  prefix="fmt"%>
<!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>查询商品列表</title>
</head>
<body> 
<form action="${pageContext.request.contextPath}/item/queryItem.action" method="post">
查询条件：
<table width="100%" border=1>
<tr>
<td><input type="submit" value="查询"/></td>
</tr>
</table>
商品列表：
<table width="100%" border=1>
<tr>
    <td>商品名称</td>
    <td>商品价格</td>
    <td>生产日期</td>
    <td>商品描述</td>
    <td>操作</td>
</tr>
<c:forEach items="${itemsList}" var="item">
<tr>
    <td>${item.name}</td>
    <td>${item.price}</td>
    <td><fmt:formatDate value="${item.createtime}" pattern="yyyy-MM-dd HH🇲🇲ss"/></td>
    <td>${item.detail}</td>

<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">td</span><span style="color: rgba(0, 0, 255, 1)">&gt;&lt;</span><span style="color: rgba(128, 0, 0, 1)">a </span><span style="color: rgba(255, 0, 0, 1)">href</span><span style="color: rgba(0, 0, 255, 1)">="${pageContext.request.contextPath }/item/editItem.action?id=${item.id}"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>修改<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">&gt;&lt;/</span><span style="color: rgba(128, 0, 0, 1)">td</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>



</tr>
</c:forEach>


</table>
</form>
</body>


</html>

7 建立 class，包名 com.hello

public class MyClass1 implements Controller {
    @Override
    public ModelAndView handleRequest(HttpServletRequest request,
            HttpServletResponse response) throws Exception {

    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">调用service查找 数据库，查询商品列表，这里使用静态数据模拟</span>
    List&lt;Items&gt; itemsList = <span style="color: rgba(0, 0, 255, 1)">new</span> ArrayList&lt;Items&gt;<span style="color: rgba(0, 0, 0, 1)">();
    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">向list中填充静态数据</span>


        
        Items items_1 = new Items();
        items_1.setName("联想笔记本");
        items_1.setPrice(6000f);
        items_1.setDetail("ThinkPad T430 联想笔记本电脑！");

    Items items_2 </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Items();
    items_2.setName(</span>"苹果手机"<span style="color: rgba(0, 0, 0, 1)">);
    items_2.setPrice(5000f);
    items_2.setDetail(</span>"iphone6苹果手机！"<span style="color: rgba(0, 0, 0, 1)">);
    
    itemsList.add(items_1);
    itemsList.add(items_2);

    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">返回ModelAndView</span>
    ModelAndView modelAndView =  <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> ModelAndView();
    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">相当 于request的setAttribut，在jsp页面中通过itemsList取数据</span>
    modelAndView.addObject("itemsList"<span style="color: rgba(0, 0, 0, 1)">, itemsList);
    
    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">指定视图</span>
    modelAndView.setViewName("/WEB-INF/view/display.jsp"<span style="color: rgba(0, 0, 0, 1)">);
    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">modelAndView.setViewName("items/itemsList");</span>

    <span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> modelAndView;
}



}

Items 类为

package com.hello;

import java.util.Date;


public class Items {
private Integer id;


</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String name;

</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> Float price;

</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String pic;

</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> Date createtime;

</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String detail;

</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> Integer getId() {
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> id;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> setId(Integer id) {
    </span><span style="color: rgba(0, 0, 255, 1)">this</span>.id =<span style="color: rgba(0, 0, 0, 1)"> id;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> String getName() {
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> name;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> setName(String name) {
    </span><span style="color: rgba(0, 0, 255, 1)">this</span>.name = name == <span style="color: rgba(0, 0, 255, 1)">null</span> ? <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)"> : name.trim();
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> Float getPrice() {
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> price;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> setPrice(Float price) {
    </span><span style="color: rgba(0, 0, 255, 1)">this</span>.price =<span style="color: rgba(0, 0, 0, 1)"> price;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> String getPic() {
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> pic;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> setPic(String pic) {
    </span><span style="color: rgba(0, 0, 255, 1)">this</span>.pic = pic == <span style="color: rgba(0, 0, 255, 1)">null</span> ? <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)"> : pic.trim();
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> Date getCreatetime() {
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> createtime;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> setCreatetime(Date createtime) {
    </span><span style="color: rgba(0, 0, 255, 1)">this</span>.createtime =<span style="color: rgba(0, 0, 0, 1)"> createtime;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> String getDetail() {
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> detail;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> setDetail(String detail) {
    </span><span style="color: rgba(0, 0, 255, 1)">this</span>.detail = detail == <span style="color: rgba(0, 0, 255, 1)">null</span> ? <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)"> : detail.trim();
}



}

 

 方式一：

配置 Bean name 作为 URL

在 springmvc.xml 中添加

<bean
        class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping" />
    <bean name="/showlist" id="list1"
        class="com.hello.MyClass1" />
    <bean
        class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter" />

 

这里 Bean name 为 /showlist, 对应类 MyClass1，他的 handleRequest 方法返回 ModelAndView 的 viewName 是

/WEB-INF/view/display.jsp

 

方式二

利用 URL 对应 bean id 的方式，

改成

    <bean name="/showlist" id="list1" class="com.hello.MyClass1" />
    <bean
        class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
        <property name="mappings">
            <props>
                <prop key="/anothershow">list1</prop>
            </props>
        </property>
    </bean>

当然适配器不可少

    <bean
        class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter" />

 

注意 <props> 可以有多个 <prop>

 

方式三

URL 映射还是使用方式 1 或者方式 2，这里修改 MyClass1 文件

public class MyClass1 implements HttpRequestHandler {
    public void handleRequest(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {

    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">调用service查找 数据库，查询商品列表，这里使用静态数据模拟</span>
    List&lt;Items&gt; itemsList = <span style="color: rgba(0, 0, 255, 1)">new</span> ArrayList&lt;Items&gt;<span style="color: rgba(0, 0, 0, 1)">();
    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">向list中填充静态数据</span>


        
        Items items_1 = new Items();
        items_1.setName("联想笔记本");
        items_1.setPrice(6000f);
        items_1.setDetail("ThinkPad T430 联想笔记本电脑！");

    Items items_2 </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Items();
    items_2.setName(</span>"苹果手机"<span style="color: rgba(0, 0, 0, 1)">);
    items_2.setPrice(5000f);
    items_2.setDetail(</span>"iphone6苹果手机！"<span style="color: rgba(0, 0, 0, 1)">);
    
    itemsList.add(items_1);
    itemsList.add(items_2);request.setAttribute(</span>"itemsList"<span style="color: rgba(0, 0, 0, 1)">, itemsList);
request.getRequestDispatcher(</span>"/WEB-INF/view/display.jsp"<span style="color: rgba(0, 0, 0, 1)">).forward(request, response);
    
}



}

添加适配器

<bean class="org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter"/>

 

方式四：使用注解的方式（终极方式）

删除以上配置

添加

 

    <context:component-scan base-package="com.hello" />
    <!--注解映射器 -->
    <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping"/>
    <!--注解适配器 -->
    <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"/>

或者推荐使用

<!-- 配置扫描的包 -->
    <context:component-scan base-package="com.hello" />

<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">mvc:annotation-driven </span><span style="color: rgba(0, 0, 255, 1)">/&gt;</span>

<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">mvc:default-servlet-handler </span><span style="color: rgba(0, 0, 255, 1)">/&gt;</span></pre>

 

新建一个类

@Controller
public class MyClass2  {
    @RequestMapping("/show")
   public ModelAndView action() throws Exception {

    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">调用service查找 数据库，查询商品列表，这里使用静态数据模拟</span>
    List&lt;Items&gt; itemsList = <span style="color: rgba(0, 0, 255, 1)">new</span> ArrayList&lt;Items&gt;<span style="color: rgba(0, 0, 0, 1)">();
    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">向list中填充静态数据</span>


        
        Items items_1 = new Items();
        items_1.setName("联想笔记本");
        items_1.setPrice(6000f);
        items_1.setDetail("ThinkPad T430 联想笔记本电脑！");

    Items items_2 </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Items();
    items_2.setName(</span>"苹果手机"<span style="color: rgba(0, 0, 0, 1)">);
    items_2.setPrice(5000f);
    items_2.setDetail(</span>"iphone6苹果手机！"<span style="color: rgba(0, 0, 0, 1)">);
    
    itemsList.add(items_1);
    itemsList.add(items_2);

    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">返回ModelAndView</span>
    ModelAndView modelAndView =  <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> ModelAndView();
    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">相当 于request的setAttribut，在jsp页面中通过itemsList取数据</span>
    modelAndView.addObject("itemsList"<span style="color: rgba(0, 0, 0, 1)">, itemsList);
    
    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">指定视图</span>
    modelAndView.setViewName("/WEB-INF/view/display.jsp"<span style="color: rgba(0, 0, 0, 1)">);
    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">modelAndView.setViewName("items/itemsList");</span>
    System.out.println("hello"<span style="color: rgba(0, 0, 0, 1)">);
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> modelAndView;

    
}



}

访问 http://localhost:8080/Test/show 即可。

 

补充

视图解析器

        <bean
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/view/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>

当使用

modelAndView.setViewName("display");
就等效于原来的
modelAndView.setViewName("/WEB-INF/view/display.jsp");
视图解析器添加前缀和后缀。