master

分支 (2)

管理

管理

master

test

in
/
MVC模型 servlet实例.txt

（1）JSP索引页面index.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<!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>Insert title here</title>
</head>
<body>
	<form action="servlet/addUser.action" method="post">
		姓名：<input type="text" name="username">
		      <input type="submit" value="提交">
	</form>
</body>
</html>

（2）业务逻辑代码UserManager
package edu.eurasia;

import java.util.ArrayList;
import java.util.List;

public class UserManager {
	public void addUser(String username) {
		System.out.println("UserManager.addUser()--->username:" + username);
	}

	public void delUser(String username) {
		System.out.println("UserManager.delUser()--->username:" + username);
	}

	public void modifyUser(String username) {
		System.out.println("UserManager.modifyUser()--->username" + username);
	}

	public List queryUser(String username) {
		System.out.println("UserManager.queryUser()--->username" + username);
		List userList = new ArrayList();
		userList.add("a");
		userList.add("b");
		userList.add("c");
		return userList;
	}
}

（3）Servlet控制代码
package edu.eurasia;

import java.io.IOException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

//@WebServlet(urlPatterns={"*.action"})
@WebServlet("/servlet/addUser.action")
public class TestServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
	public TestServlet() {
		super();
		// TODO Auto-generated constructor stub
	}

	protected void doGet(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {

request.setCharacterEncoding("UTF-8");

String requestURI = request.getRequestURI();//获取该页面的相对路径
		System.out.println("requestURI=" + requestURI);

		String path = requestURI.substring(requestURI.indexOf("/", 1),
				requestURI.indexOf("."));
		System.out.println("path=" + path);

		String username = request.getParameter("username");
		UserManager userManager = new UserManager();

		String forward = "";
		if ("/servlet/delUser".equals(path)) {
			userManager.delUser(username);
			forward = "/del_success.jsp";
		} else if ("/servlet/addUser".equals(path)) {
			userManager.addUser(username);
			forward = "/add_success.jsp";
		} else if ("/servlet/modifyUser".equals(path)) {
			userManager.modifyUser(username);
			forward = "/modify_success.jsp";
		} else if ("/servlet/queryUser".equals(path)) {
			List userList = userManager.queryUser(username);
			request.setAttribute("userList", userList);
			forward = "/query_success.jsp";
		} else {
			throw new RuntimeException("请求失败");
		}
request.setAttribute("u", username);
		request.getRequestDispatcher(forward).forward(request, response);

	}

	protected void doPost(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}
}
注解@WebServlet用于在Web应用程序中标记一个继承了HttpServlet的类为Servlet。其属性urlPatterns的值即是web.xml中的url-pattern。
request.getRequestDispatcher()是请求转发，前后页面共享一个request.
response.sendRedirect()是重新定向 前后页面不是一个request.
控制台输出：
/Day02_01/servlet/addUser.action
path=/servlet/addUser
UserManager.addUser()--->username:张三疯

（4）add_success.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<!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>Insert title here</title>
</head>
<body>
	<h1>addUser
	 <%=request.getAttribute("u") %>
	<%--  <%=request.getParameter("username") %> --%>
${requestScope.u}
	success!</h1>
</body>
</html>
这个servlet代码主要实现的功能判断是那个页面请求服务器做那些操作，之后调用业务逻辑实现相应业务操作。

（5）配置Servlet
<?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>strut2_1</display-name>
  <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>
  <servlet>
    <description></description>
    <display-name>TestServlet</display-name>
    <servlet-name>TestServlet</servlet-name>
    <servlet-class>edu.eurasia.TestServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>TestServlet</servlet-name>
    <url-pattern>*.action</url-pattern>
  </servlet-mapping>
</web-app>