Netbeans MySQL连接 - 与jbdc无关(Netbeans MySQL Connection - not to do with jbdc)

 我有一个登录应用程序，需要连接到服务器以检查用户名和密码。 我正在使用netbeans并安装了jbdc并在服务选项卡中工作（感谢堆栈溢出！）。 通过jbdc工作我的意思是我可以通过它执行SQL脚本。 
 
 我已经使用MS Server 16和MySQL进行了设置，所以我确信这是代码： 
 
 连接方式： 
 
package dbUtil;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class dbConnection {
    private static final String USERNAME = "root";
    private static final String PASSWORD = "mess";
    private static final String SQCONN = "jdbc:mysql://localhost:1434/MessyLogin?zeroDateTimeBehavior=convertToNull";


    public static Connection getConnection()throws SQLException{

        try {
            Class.forName("com.mysql.jdbc.Driver");
            return DriverManager.getConnection(SQCONN, USERNAME, PASSWORD);
        }catch (ClassNotFoundException e) {
        }
        return null;
    }
}
 
 loginmodel： 
 
package LogIn;


import dbUtil.dbConnection;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;



public class LogInModel {
    Connection connection;

    public LogInModel() {
        try{

            this.connection = dbConnection.getConnection();

        }catch(SQLException e){

        }

        if(this.connection == null){
            System.out.println("here");
            // System.exit(1);
        }
    }
    public boolean isDatabaseConnected(){
        return this.connection != null;
    }

    public boolean isLogin(String username, String password) throws Exception{
        PreparedStatement pr = null;
        ResultSet rs = null;

        String sql = "SELECT * FROM MessyLogin where username = ? and Password = ?";

        try{
            pr = this.connection.prepareStatement(sql);
            pr.setString(1, username);
            pr.setString(2, password);

            rs = pr.executeQuery();

            boolean bool1;

            if(rs.next()){
                return true;
            }
            return false;
        }
        catch(SQLException ex){        
            return false;
        }

        finally {
            {
                pr.close();
                rs.close();
            }
        }
    }  

}
 
 我相信问题是return null; 来自dbConnection文件。 if(this.connection==Null)返回true并且系统正在退出。 
 
 先谢谢你。 

I have a login app that needs to connect to a server to check the username and password. I am using netbeans and the jbdc is installed and working in the services tab(thanks stack overflow!). By the jbdc is work I mean that i can execute SQL script through it.
 
I have set this up with MS Server 16 and MySQL so I am convied it is the code:
 
Connection method:
 
package dbUtil;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class dbConnection {
    private static final String USERNAME = "root";
    private static final String PASSWORD = "mess";
    private static final String SQCONN = "jdbc:mysql://localhost:1434/MessyLogin?zeroDateTimeBehavior=convertToNull";


    public static Connection getConnection()throws SQLException{

        try {
            Class.forName("com.mysql.jdbc.Driver");
            return DriverManager.getConnection(SQCONN, USERNAME, PASSWORD);
        }catch (ClassNotFoundException e) {
        }
        return null;
    }
}
 
loginmodel:
 
package LogIn;


import dbUtil.dbConnection;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;



public class LogInModel {
    Connection connection;

    public LogInModel() {
        try{

            this.connection = dbConnection.getConnection();

        }catch(SQLException e){

        }

        if(this.connection == null){
            System.out.println("here");
            // System.exit(1);
        }
    }
    public boolean isDatabaseConnected(){
        return this.connection != null;
    }

    public boolean isLogin(String username, String password) throws Exception{
        PreparedStatement pr = null;
        ResultSet rs = null;

        String sql = "SELECT * FROM MessyLogin where username = ? and Password = ?";

        try{
            pr = this.connection.prepareStatement(sql);
            pr.setString(1, username);
            pr.setString(2, password);

            rs = pr.executeQuery();

            boolean bool1;

            if(rs.next()){
                return true;
            }
            return false;
        }
        catch(SQLException ex){        
            return false;
        }

        finally {
            {
                pr.close();
                rs.close();
            }
        }
    }  

}
 
I believe the issue is the return null; from the dbConnection file. The if(this.connection==Null) comes back true and the system is exiting. 
 
Thank you in advance.

原文：https://stackoverflow.com/questions/45916622