javaweb:jsp+servlet登錄（請(qǐng)求轉(zhuǎn)發(fā)RequestDispatcher+setAttribute請(qǐng)求對(duì)象存儲(chǔ)數(shù)據(jù)
來(lái)源：我的學(xué)習(xí)筆記
登錄JSP代碼自己寫就行了
代碼：
package servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
?* Servlet implementation class LoginServlet
?*/
@WebServlet(name = "LoginServlet", urlPatterns = { "/user-login" }) /* 要和JSP文件表單中的action路徑保持一致 */
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
? ? ? ?
? ? /**
? ? ?* @see HttpServlet#HttpServlet()
? ? ?*/
? ? public LoginServlet() {
? ? ? ? super();
? ? ? ? // TODO Auto-generated constructor stub
? ? }
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
String username = request.getParameter("username");/* 用來(lái)接受來(lái)自JSP文件中的表單數(shù)據(jù) */
String password=request.getParameter("password");
response.setContentType("text/html;charset=UTF-8");
PrintWriter out=response.getWriter();
out.println("<!DOCTYPE html>");
out.println("<html><body>");
if (username.equals("123456") && password.equals("123456")) {/* 設(shè)置用戶名，密碼都為123456 */
request.setAttribute("username", username);//指定名字name的對(duì)象obj作為屬性值儲(chǔ)存到請(qǐng)求對(duì)象中
RequestDispatcher rd=request.getRequestDispatcher("/welcome.jsp");
rd.forward(request, response);
}else {
RequestDispatcher rd=request.getRequestDispatcher("/false.jsp");
rd.forward(request, response);
}
out.println("</body></html>");
}
}
代碼：
<%@ page language="java" contentType="text/html; charset=UTF-8"
? ? pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>success</title>
</head>
<body>
<h1>登陸成功！歡迎您，${username}!</h1>
<!-- LoginServlet中的? request.setAttribute("username", username);?
（“XXXX”，“YYYY”）將YYYY傳到${XXXX}里面-->
</body>
</html>
代碼：
<%@ page language="java" contentType="text/html; charset=UTF-8"
? ? pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>false</title>
</head>
<body>
<h1>用戶名或密碼有誤，請(qǐng)進(jìn)行檢查</h1>
<form action="login.jsp" method="post">
<input type="submit" value="返回">
</form>
</body>
</html>
