well 我有一個帶登錄表單的jsp頁面,我使用的是servlet,如果用戶名和密碼正確,那麼servlet會將用戶重定向到其他頁面,否則它會重定向他到登錄頁面,再次如何從servlet重定向到jsp頁面
當我登錄使用正確的用戶名和密碼,我正在重定向完美的reservation.jsp但是當我把形式錯誤的用戶名或密碼,當我點擊提交按鈕的頁面成爲空白
這裏是servlet
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.*;
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;
import javax.servlet.http.HttpSession;
import com.mysql.jdbc.PreparedStatement;
/**
* Servlet implementation class LogServlet
*/
@WebServlet("/LogServlet")
public class LogServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public LogServlet() {
super();
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.setContentType("text/html");
String name=request.getParameter("name");
String password=request.getParameter("password");
PreparedStatement ps = null;
ResultSet rs = null;
try {
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/log",
"root","");
ps = (PreparedStatement) conn.prepareStatement("select nom_client,username,password from client where username = ? and password = ?");
ps.setString(1, name);
ps.setString(2, password);
rs=ps.executeQuery();
try {
while(rs.next()){
if(password.equals(rs.getString("password")) && name.equals(rs.getString("username"))){
HttpSession session=request.getSession();
session.setAttribute("name",name);
PrintWriter out=response.getWriter();
request.getRequestDispatcher("reservation.jsp").include(request, response);
}
else{
response.sendRedirect("/login.jsp");
}}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.close();
}
catch(Exception e){e.printStackTrace();}
}
}
檢查這一點,如果這可能對你有幫助 http://stackoverflow.com/questions/18576159/automatically-redirect-from-one-jsp-page-to-another –
此外,你不應該巢嘗試catch塊 –