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>
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
<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>
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="${item.createtime}" pattern="yyyy-MM-dd HH:mm:ss"/></td> <td>${item.detail }</td> <td><a href="${pageContext.request.contextPath }/item/editItem.action?id=${item.id}">修改</a></td> </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 { //调用service查找 数据库,查询商品列表,这里使用静态数据模拟 List<Items> itemsList = new ArrayList<Items>(); //向list中填充静态数据 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 = new Items(); items_2.setName("苹果手机"); items_2.setPrice(5000f); items_2.setDetail("iphone6苹果手机!"); itemsList.add(items_1); itemsList.add(items_2); //返回ModelAndView ModelAndView modelAndView = new ModelAndView(); //相当 于request的setAttribut,在jsp页面中通过itemsList取数据 modelAndView.addObject("itemsList", itemsList); //指定视图 modelAndView.setViewName("/WEB-INF/view/display.jsp"); //modelAndView.setViewName("items/itemsList"); return modelAndView; } }
Items类为
package com.hello; import java.util.Date; public class Items { private Integer id; private String name; private Float price; private String pic; private Date createtime; private String detail; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name == null ? null : name.trim(); } public Float getPrice() { return price; } public void setPrice(Float price) { this.price = price; } public String getPic() { return pic; } public void setPic(String pic) { this.pic = pic == null ? null : pic.trim(); } public Date getCreatetime() { return createtime; } public void setCreatetime(Date createtime) { this.createtime = createtime; } public String getDetail() { return detail; } public void setDetail(String detail) { this.detail = detail == null ? null : 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 { //调用service查找 数据库,查询商品列表,这里使用静态数据模拟 List<Items> itemsList = new ArrayList<Items>(); //向list中填充静态数据 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 = new Items(); items_2.setName("苹果手机"); items_2.setPrice(5000f); items_2.setDetail("iphone6苹果手机!"); itemsList.add(items_1); itemsList.add(items_2);request.setAttribute("itemsList", itemsList); request.getRequestDispatcher("/WEB-INF/view/display.jsp").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" /> <mvc:annotation-driven /> <mvc:default-servlet-handler />
新建一个类
@Controller public class MyClass2 { @RequestMapping("/show") public ModelAndView action() throws Exception { //调用service查找 数据库,查询商品列表,这里使用静态数据模拟 List<Items> itemsList = new ArrayList<Items>(); //向list中填充静态数据 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 = new Items(); items_2.setName("苹果手机"); items_2.setPrice(5000f); items_2.setDetail("iphone6苹果手机!"); itemsList.add(items_1); itemsList.add(items_2); //返回ModelAndView ModelAndView modelAndView = new ModelAndView(); //相当 于request的setAttribut,在jsp页面中通过itemsList取数据 modelAndView.addObject("itemsList", itemsList); //指定视图 modelAndView.setViewName("/WEB-INF/view/display.jsp"); //modelAndView.setViewName("items/itemsList"); System.out.println("hello"); return 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。