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📜  Servlet中的登录表单

📅  最后修改于: 2021-01-09 13:40:23             🧑  作者: Mango

Servlet教程中的登录表单示例

在这里，我们将创建一个简单的示例，以使用servlet创建登录表单。我们已经使用oracle10g作为数据库。此应用程序需要5个文件。

  • index.html
  • FirstServlet.java
  • LoginDao.java
  • SecondServlet.java
  • web.xml

您必须创建带有名称和传递字段的表userreg。而且，它必须包含一些数据。该表应为：

create table userreg(name varchar2(40),pass varchar2(40));


Name:


Password:






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 FirstServlet extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {

    response.setContentType("text/html");
    PrintWriter out = response.getWriter();
        
    String n=request.getParameter("username");
    String p=request.getParameter("userpass");
        
    if(LoginDao.validate(n, p)){
        RequestDispatcher rd=request.getRequestDispatcher("servlet2");
        rd.forward(request,response);
    }
    else{
        out.print("Sorry username or password error");
        RequestDispatcher rd=request.getRequestDispatcher("index.html");
        rd.include(request,response);
    }
        
    out.close();
    }
}

import java.sql.*;

public class LoginDao {
public static boolean validate(String name,String pass){
boolean status=false;
try{
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con=DriverManager.getConnection(
"jdbc:oracle:thin:@localhost:1521:xe","system","oracle");
    
PreparedStatement ps=con.prepareStatement(
"select * from userreg where name=? and pass=?");
ps.setString(1,name);
ps.setString(2,pass);
    
ResultSet rs=ps.executeQuery();
status=rs.next();
        
}catch(Exception e){System.out.println(e);}
return status;
}
}

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 WelcomeServlet extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {

    response.setContentType("text/html");
    PrintWriter out = response.getWriter();
        
    String n=request.getParameter("username");
    out.print("Welcome "+n);
        
    out.close();
    }

}