springmvc框架
第一步:发起请求到前端控制器(DispatcherServlet)
第二步:前端控制器请求HandlerMapping查找 Handler
可以根据xml配置、注解进行查找
第三步:处理器映射器HandlerMapping向前端控制器返回Handler
第四步:前端控制器调用处理器适配器去执行Handler
第五步:处理器适配器去执行Handler
第六步:Handler执行完成给适配器返回ModelAndView
第七步:处理器适配器向前端控制器返回ModelAndView
ModelAndView是springmvc框架的一个底层对象,包括 Model和view
第八步:前端控制器请求视图解析器去进行视图解析
根据逻辑视图名解析成真正的视图(jsp)
第九步:视图解析器向前端控制器返回View
第十步:前端控制器进行视图渲染
视图渲染将模型数据(在ModelAndView对象中)填充到request域
第十一步:前端控制器向用户响应结果
组件:
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…)
ItemList1.java
package cc.sjtu.controller;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;
import cc.sjtu.po.Items;
public class ItemList1 implements Controller {
@Override
public ModelAndView handleRequest(HttpServletRequest arg0,
HttpServletResponse arg1) throws Exception {
//商品列表
List<Items> itemsList = new ArrayList<Items>();
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);
//创建modelAndView准备填充数据、设置视图
ModelAndView modelAndView = new ModelAndView();
//填充数据
modelAndView.addObject("itemsList", itemsList);
//视图
modelAndView.setViewName("/WEB-INF/jsps/itemsList.jsp");
return modelAndView;
}
}
ItemList2.java
package cc.sjtu.controller;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.HttpRequestHandler;
import cc.sjtu.po.Items;
public class ItemList2 implements HttpRequestHandler {
@Override
public void handleRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// 商品列表
List<Items> itemsList = new ArrayList<Items>();
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("iphone5 苹果手机!");
itemsList.add(items_1);
itemsList.add(items_2);
// 填充数据
request.setAttribute("itemsList", itemsList);
// 视图
request.getRequestDispatcher("/WEB-INF/jsps/itemsList.jsp").forward(request, response);
}
}
Items.java
package cc.sjtu.po;
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();
}
}
springmvc.xml
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd ">
<!-- controller配置 -->
<bean name="/items1.action" id="itemList1" class="cc.sjtu.controller.ItemList1"/>
<bean name="/items2.action" id="itemList2" class="cc.sjtu.controller.ItemList2"/>
<!-- 处理器映射器 -->
<!-- 根据bean的name进行查找Handler 将action的url配置在bean的name中 -->
<bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping" />
<!-- 处理器适配器 implements Controller -->
<bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"/>
<!-- 视图解析器 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" />
<!-- /////////////// 可以换映射器,两个映射器可以共存 ////////////// -->
<!-- 简单url映射 -->
<bean class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
<property name="mappings">
<props>
<prop key="/items12.action">itemList1</prop>
<prop key="/items13.action">itemList1</prop>
</props>
</property>
</bean>
<!-- //////////////////////////////////////////////////////////////// -->
<!-- ////////////////// 可以换适配器,两个适配器可以共存/////////////////// -->
<bean class="org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter"/>
<!-- //////////////////////////////////////////////////////////////// -->
</beans>
itemsList.jsp
<%@ 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>
web.xml
<?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_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>springmvc</display-name>
<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:springmvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>*.action</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>