Jakarta ee 不正确的数据会将用户从Servlet登录页重定向到空白页
在我的项目中,用户通过提供他/她的Jakarta ee 不正确的数据会将用户从Servlet登录页重定向到空白页,jakarta-ee,servlets,login,Jakarta Ee,Servlets,Login,在我的项目中,用户通过提供他/她的emailid和密码登录。如果两者匹配,则可以成功登录。如果没有,他将被重定向到UserHome.jsp页面。这是我的密码: import getset.Getset; import java.io.IOException; import java.io.PrintWriter; import java.sql.ResultSet; import java.sql.SQLException; import javax.servlet.ServletExcep
emailid
和密码登录。如果两者匹配,则可以成功登录。如果没有,他将被重定向到UserHome.jsp
页面。这是我的密码:
import getset.Getset;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import accessdb.Dao;
public class LoginAuthentication extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// Authentication and Logging in The Registered User
Getset g=new Getset();
Dao dao=new Dao();
String userid="";
String fname="";
// PrintWriter pw=response.getWriter();
String loginemail=request.getParameter("loginemail");
String loginpassword=request.getParameter("loginpassword");
if (loginemail.equals("") ||
loginemail.equals(" ") ||
loginpassword.equals("") ||
loginpassword.equals(" "))
response.sendRedirect("WelcomePage.jsp");
g.setloginemail(loginemail);
g.setloginpassword(loginpassword);
try {
ResultSet rs=dao.loginauthentication(g);
while(rs.next())
{
String regemail=rs.getString("regemail");
String regpassword=rs.getString("regpassword");
if(loginemail.equals(regemail) &&
(loginpassword.equals(regpassword))==true)
{
ResultSet rs1=dao.getnameid(g);
while(rs1.next())
{
userid=rs1.getString("USERID");
fname=rs1.getString("FNAME");
}
HttpSession session = request.getSession(true);
session.setAttribute("USERID", userid);
session.setAttribute("FNAME", fname);
response.sendRedirect("UserHome.jsp");
break;
}
else if(loginemail.equals(regemail) && (loginpassword.equals(regpassword))==false)
{
response.sendRedirect("WelcomePage.jsp");
return;
}
}
}
catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
我已尝试涵盖登录期间可能出现的所有情况。如果出现以下情况,则用户无法访问
两个字段都保持为空
电子邮件
已填写(包含正确或不正确的数据),但密码
未填写
password
已填写(数据正确或不正确),但未填写emailid
我试图涵盖的领域是,如果任何字段填充了不正确的数据,则不允许用户访问。对于这一部分,我在代码中编写了:
if(loginemail.equals(regemail) && (loginpassword.equals(regpassword))==true)
//user accesses
else
if(loginemail.equals(regemail) && (loginpassword.equals(regpassword))==false)
//user cannot access
但我不知道为什么它没有显示预期的行为,当两个字段都填充了不正确的数据时,用户被重定向到一个空白页
添加:我也尝试了
if(loginemail.equals(regemail) && (loginpassword.equals(regpassword)))
//User accesses
else if(!loginemail.equals(regemail) || (!loginpassword.equals(regpassword)))
//User cannot access
但它也无能为力 使用简单的
else
而不是
else if(loginemail.equals(regemail) && (loginpassword.equals(regpassword))==false)
另外,请查收
例如,您有loginemail.equals(regemail)和&(loginpassword.equals(regpassword))==false
,这似乎被视为:false&&false==false
,它将返回false。您将得到一个空白页。这意味着代码中的if
条件都没有被执行以重定向到页面
我没有得到你想要达到的目标。理想情况下,您应该只有两个条件:
在电子邮件和密码正确的情况下重定向到UsersHome
如果其中一个页面不正确,请重定向到欢迎页面
代码段:
// Servlet instance variable
String redirectPage = "WelcomePage.jsp";
改变
if(loginemail.equals("")||loginemail.equals(" ")||loginpassword.equals("")||loginpassword.equals(" "))
response.sendRedirect("WelcomePage.jsp");
到
经过长时间的尝试,我终于得到了我的工作代码。这是:
import getset.Getset;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import accessdb.Dao;
public class LoginAuthentication extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// Authentication and Logging in The Registered User
Getset g=new Getset();
Dao dao=new Dao();
String userid="";
String fname="";
// PrintWriter pw=response.getWriter();
String loginemail=request.getParameter("loginemail");
String loginpassword=request.getParameter("loginpassword");
if(loginemail.equals("")||loginemail.equals(" ")||loginpassword.equals("")||loginpassword.equals(" "))
{
response.sendRedirect("WelcomePage.jsp");
}
else{
g.setloginemail(loginemail);
g.setloginpassword(loginpassword);
try {
ResultSet rs=dao.loginauthentication(g);
while(rs.next()) //Fetching all emails and passwords from user table
{
String regemail=rs.getString("regemail");
String regpassword=rs.getString("regpassword");
System.out.println(""+regemail);
if(loginemail.equals(regemail) && (loginpassword.equals(regpassword)))
{
System.out.println("55555");
ResultSet rs1=dao.getnameid(g);
while(rs1.next()) //GET USERID and name FROM NEWUSER TO USE AS PRIMARY KEY
{
userid=rs1.getString("USERID");
fname=rs1.getString("FNAME");
System.out.println(""+userid);
}
HttpSession session = request.getSession(true);
session.setAttribute("USERID", userid);
session.setAttribute("FNAME", fname);
response.sendRedirect("UserHome.jsp");
break;
}
}
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
谢谢所有试图帮助我的人 您提到:“如果两个字段都填写了不正确的数据,请不要让用户访问”。理想情况下,如果电子邮件或密码不可用,则不应允许登录incorrect@Hardik米什拉:你说得对。我将相应地更改代码。这是真的。我还想实现,如果任何字段为空,用户将被重定向到欢迎页面。@SubirAdhikari:检查编辑的答案。Dpn不复制粘贴所有内容。它的代码片段,在代码中进行调整。好的。尝试一下。只是想知道创建redirectMyPage
extra的功能是什么?@SubirAdhikari:尝试调试代码。我只是想了个主意。我没有试过。也许有一些逻辑上的缺陷应该被引入。你确定它适用于不正确的电子邮件和密码吗?如果是我surprised@HardikMishra对它完全起作用了。但你为什么感到惊讶?有什么问题吗?
import getset.Getset;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import accessdb.Dao;
public class LoginAuthentication extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// Authentication and Logging in The Registered User
Getset g=new Getset();
Dao dao=new Dao();
String userid="";
String fname="";
// PrintWriter pw=response.getWriter();
String loginemail=request.getParameter("loginemail");
String loginpassword=request.getParameter("loginpassword");
if(loginemail.equals("")||loginemail.equals(" ")||loginpassword.equals("")||loginpassword.equals(" "))
{
response.sendRedirect("WelcomePage.jsp");
}
else{
g.setloginemail(loginemail);
g.setloginpassword(loginpassword);
try {
ResultSet rs=dao.loginauthentication(g);
while(rs.next()) //Fetching all emails and passwords from user table
{
String regemail=rs.getString("regemail");
String regpassword=rs.getString("regpassword");
System.out.println(""+regemail);
if(loginemail.equals(regemail) && (loginpassword.equals(regpassword)))
{
System.out.println("55555");
ResultSet rs1=dao.getnameid(g);
while(rs1.next()) //GET USERID and name FROM NEWUSER TO USE AS PRIMARY KEY
{
userid=rs1.getString("USERID");
fname=rs1.getString("FNAME");
System.out.println(""+userid);
}
HttpSession session = request.getSession(true);
session.setAttribute("USERID", userid);
session.setAttribute("FNAME", fname);
response.sendRedirect("UserHome.jsp");
break;
}
}
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}