Question

**loginServlet.java**

package com.anil.apps;

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 LoginServlet extends HttpServlet {
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        PrintWriter out=response.getWriter();

        String uid=request.getParameter("userid");
        String password=request.getParameter("pwd");

        if(uid.equals("Anil")&&password.equals("missinlx")){
            //out.println("welcome "+uid);
            response.sendRedirect("welcomeUser?userid="+uid);
        }
        else{
            out.println("invalid username or password");
        }
    }

}






**WelcomeUserServlet.java**

package com.anil.apps;

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 WelcomeUserServlet extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        PrintWriter out=response.getWriter();

        out.println("<html><body><h1>Welcome " +uid+ "</h1></body></html>");
    }

}

我的代码出了什么问题？我想使用response.sendRedirect（）方法将页面重定向到welcomeUser.java页面。因为我是servlet的新手，请帮助我。请告诉我Servlet中页面重定向的完整格式。

Answer 1

GET参数不会自动转入变量。您需要将其添加到doGet：

中WelcomeUserServlet方法的顶部

String uid = request.getParameter("userId");

使该课程看起来像这样：

public class WelcomeUserServlet extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String uid = request.getParameter("userId");
        PrintWriter out=response.getWriter();

        out.println("<html><body><h1>Welcome " +uid+ "</h1></body></html>");
    }

}

Answer 2

您对sendRedirect方法使用了错误的参数

你应该使用像

这样的完整路径

response.sendRedirect("some/path/here/to/"+welcomeUser?userid="+uid)

或更好

response.sendRedirect(response.encodeURL(response.getContextPath()+"welcomeUser?userid="+uid))

或者使用知道项目结构且不需要完整路径的请求调度程序

request.getRequestDispatcher("welcomeUser?userid="+uid).forward(request,response)

如何使用response.sendRedirect（）方法重定向到Servlet中的另一个页面？

2 个答案: