AJAX连接后台数据库检验用户名是否已被使用------AJAX

淩亂°似流年 2024-02-18 10:13 14阅读 0赞

>     package com.bjpowernode.AJAX.servlet;
>     
>     import com.bjpowernode.oa.utils.DBUtil;
>     import jakarta.servlet.ServletException;
>     import jakarta.servlet.annotation.WebServlet;
>     import jakarta.servlet.http.HttpServlet;
>     import jakarta.servlet.http.HttpServletRequest;
>     import jakarta.servlet.http.HttpServletResponse;
>     
>     import java.io.IOException;
>     import java.io.PrintWriter;
>     import java.sql.Connection;
>     import java.sql.PreparedStatement;
>     import java.sql.ResultSet;
>     import java.sql.SQLException;
>     
>     @WebServlet("/ajaxRequestTest")
>     public class ajaxRequestTest extends HttpServlet
>     {
>         @Override
>         protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             request.setCharacterEncoding("UTF-8");
>             response.setContentType("text/html;charset=UTF-8");
>             response.setCharacterEncoding("UTF-8");
>             PrintWriter out = response.getWriter();
>             String username = request.getParameter("username");
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 String sql = "select * from t_user where username = ?";
>                 statement = connection.prepareStatement(sql);
>                 statement.setString(1,username);
>                 resultSet = statement.executeQuery();
>                 if(resultSet.next())
>                 {
>                     out.println("该用户名已被使用");
>                 }
>                 else
>                 {
>                     out.println("随便吧");
>                 }
>             }
>             catch (SQLException e)
>             {
>                 throw new RuntimeException(e);
>             }
>     
>         }
>     }
> 
>     package com.bjpowernode.AJAX.servlet;
>     
>     import com.bjpowernode.oa.utils.DBUtil;
>     import jakarta.servlet.ServletException;
>     import jakarta.servlet.annotation.WebServlet;
>     import jakarta.servlet.http.HttpServlet;
>     import jakarta.servlet.http.HttpServletRequest;
>     import jakarta.servlet.http.HttpServletResponse;
>     
>     import java.io.IOException;
>     import java.io.PrintWriter;
>     import java.sql.Connection;
>     import java.sql.PreparedStatement;
>     import java.sql.ResultSet;
>     import java.sql.SQLException;
>     
>     @WebServlet("/ajaxRequestTest")
>     public class ajaxRequestTest extends HttpServlet
>     {
>         @Override
>         protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             request.setCharacterEncoding("UTF-8");
>             response.setContentType("text/html;charset=UTF-8");
>             response.setCharacterEncoding("UTF-8");
>             PrintWriter out = response.getWriter();
>             String username = request.getParameter("username");
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 String sql = "select * from t_user where username = ?";
>                 statement = connection.prepareStatement(sql);
>                 statement.setString(1,username);
>                 resultSet = statement.executeQuery();
>                 if(resultSet.next())
>                 {
>                     out.println("该用户名已被使用");
>                 }
>                 else
>                 {
>                     out.println("随便吧");
>                 }
>             }
>             catch (SQLException e)
>             {
>                 throw new RuntimeException(e);
>             }
>     
>         }
>     }