Servlet中include方法和forward方法的區別
/*login.jsp*/
<%@ page contentType="text/html;charset=GBK" language="java" pageEncoding="GBK"%>
<html>
<head>
<%
request.setCharacterEncoding("GBK");
%>
<meta http-equiv="Content-Type" content="text/html; charset=GBK" />
<title></title>
</head>
<body>
<form action="login.do" name="LoginForm" method="get">
使用者名稱：<input type="text" name="uname"><br>
密 碼：<input type="password" name="upwd"><br>
<input type="hidden" name="uid" value="432022199008081888">
<input type="submit" value="登陸">
<input type="reset" value="重置">
</form>
</body>
</html>
/*LoginServlet*/
package com.session;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LoginServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html; charset=GBK");
request.setCharacterEncoding("GBK");
response.setCharacterEncoding("GBK");
String uname = request.getParameter("uname");
String upwd = request.getParameter("upwd");
String uid = request.getParameter("uid");
RequestDispatcher rd = request.getRequestDispatcher("forward.do");
if ("".equals(uname) || "".equals(upwd)) {
response.sendRedirect("bad.html");
} else {
rd.forward(request, response);
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
/*ForwardServlet*/
package com.session;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ForwardServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
request.setCharacterEncoding("GBK");
String uname = request.getParameter("uname");
String upwd = request.getParameter("upwd");
String uid = request.getParameter("uid");
out.println("<!DOCTYPE HTML PUBLIC /"-//W3C//DTD HTML 4.01 Transitional//EN/">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.println("uname: " + uname + "<br>");
out.println("upwd: " + upwd + "<br>");
out.println("uid: " + uid + "<br>");
RequestDispatcher rd = request.getRequestDispatcher("include.do");
rd.include(request, response);
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
/*IncludeServlet*/
package com.session;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class IncludeServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<!DOCTYPE HTML PUBLIC /"-//W3C//DTD HTML 4.01 Transitional//EN/">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.print(" This is a forward servlet");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
/*
其實Servlet的forward方法就是將請求繼續往下傳，因此在這個過程中，傳遞的引數一直都是可以訪問到的
include的方法其實是將另一個servlet中的輸出內容包含進來
*/