Question

现在我在这里看到了一些问题，但我的问题有点不同。我创建了一个Create Account页面和Login页面。我在MYSQL中创建了一个数据库，其中存储了各种用户名和相应的密码。我使用创建帐户页面创建了一个帐户，然后通过“登录”页面进行了检查，发现它正在运行。但后来我尝试编写一个代码，在创建相应帐户后自动在MYSQL中创建表。但我得到了上述错误。我将向您显示我的登录和创建帐户页面。

LOGIN： -

import java.awt.*;

import java.awt.event.*;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.Statement;

import javax.swing.*;

public class Login extends Frame implements ActionListener, WindowListener

{

    Label l1,l2,l3;

    JTextField t1;

    JPasswordField p1;

    JButton b0,b1;

    String url = "jdbc:mysql://localhost:3306/database1";

    String user = "root";

    String password = "Newyear2016!";

    char[] s2;

    String s1,s3;

    Login()

    {

        addWindowListener(this);

        setTitle("Login");

        setSize(500,500);

        setLayout(null);

        setVisible(true);

        l3 = new Label("Login");

        l3.setBounds(120,50,300,50);

        add(l3);

        Font myFont1 = new Font("Helvetica",Font.ITALIC,30);

        l3.setFont(myFont1);

        l1 = new Label("User Name: ");

        l1.setBounds(50,150,100,50);

        add(l1);

        l2 = new Label("Password: ");

        l2.setBounds(50,250,100,50);

        add(l2);

        t1 = new JTextField();

        p1 = new JPasswordField();

        t1.setBounds(170,150,250,50);

        p1.setBounds(170,250,250,50);

        add(t1);

        add(p1);

        t1.addActionListener(this);

        p1.addActionListener(this);

        b0 = new JButton("Login");

        b0.setBounds(170,350,100,50);

        add(b0);

        b0.addActionListener(this);

        b1 = new JButton("Go Back");

        b1.setBounds(300,350,100,50);

        add(b1);

        b1.addActionListener(this);

    }

    public void actionPerformed(ActionEvent e) 

    {

        s1 = t1.getText();

        s2 = p1.getPassword();

        s3 = new String(s2);        

        Object o = e.getSource();

        if(o == b1)

        {

            dispose();

            Home h = new Home();

        }

        mainLoop:

        if(o == b0)

        {

            try

            {

                Connection myConn = 

DriverManager.getConnection(url,user,password);

                Statement myStmt = myConn.createStatement();

                ResultSet myRs = myStmt.executeQuery("select * from login");

                while(myRs.next())

                {


if(s1.equals(myRs.getString("usname"))&&s3.equals(myRs.getString("pwd")))

                    {

                        System.out.println("Username Found");

                        System.out.println("Password Found");

                        JOptionPane.showMessageDialog(null,"Login Successful: 

"+s1 );

                        break mainLoop;

                    }



                }

                JOptionPane.showMessageDialog(null,"Wrong Username/Password");



            }   

catch(Exception exc)

{

    exc.printStackTrace();

}
        }

    }


    public void windowClosing(WindowEvent e) 

{  

        dispose();  

    }

    public void windowActivated(WindowEvent e) {}

    public void windowClosed(WindowEvent e) {}

    public void windowDeactivated(WindowEvent e) {}

    public void windowDeiconified(WindowEvent e) {}

    public void windowIconified(WindowEvent e) {}

    public void windowOpened(WindowEvent e) {}

}

请告诉我我做错了什么。我已经检查过我提供了正确的密码。所以这不是问题。

创建帐户： -

import java.awt。*;

import java.awt.event。*;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.Statement;

导入javax.swing。*;

public class Login extends Frame实现了ActionListener，WindowListener

{

Label l1,l2,l3;

JTextField t1;

JPasswordField p1;

JButton b0,b1;

String url = "jdbc:mysql://localhost:3306/database1";

String user = "root";

String password = "Newyear2016!";

char[] s2;

String s1,s3;

Login()

{

    addWindowListener(this);

    setTitle("Login");

    setSize(500,500);

    setLayout(null);

    setVisible(true);

    l3 = new Label("Login");

    l3.setBounds(120,50,300,50);

    add(l3);

    Font myFont1 = new Font("Helvetica",Font.ITALIC,30);

    l3.setFont(myFont1);

    l1 = new Label("User Name: ");

    l1.setBounds(50,150,100,50);

    add(l1);

    l2 = new Label("Password: ");

    l2.setBounds(50,250,100,50);

    add(l2);

    t1 = new JTextField();

    p1 = new JPasswordField();

    t1.setBounds(170,150,250,50);

    p1.setBounds(170,250,250,50);

    add(t1);

    add(p1);

    t1.addActionListener(this);

    p1.addActionListener(this);

    b0 = new JButton("Login");

    b0.setBounds(170,350,100,50);

    add(b0);

    b0.addActionListener(this);

    b1 = new JButton("Go Back");

    b1.setBounds(300,350,100,50);

    add(b1);

    b1.addActionListener(this);

}

public void actionPerformed(ActionEvent e) 

{

    s1 = t1.getText();

    s2 = p1.getPassword();

    s3 = new String(s2);        

    Object o = e.getSource();

    if(o == b1)

    {

        dispose();

        Home h = new Home();

    }

    mainLoop:

    if(o == b0)

    {

        try

        {

            Connection myConn =

的DriverManager.getConnection（URL，用户名，密码）;

            Statement myStmt = myConn.createStatement();

            ResultSet myRs = myStmt.executeQuery("select * from login");

            while(myRs.next())

            {

如果（s1.equals（myRs.getString（＆＃34; usname＆＃34））及;＆安培; s3.equals（myRs.getString（＆＃34; PWD＆＃34;）））

                {

                    System.out.println("Username Found");

                    System.out.println("Password Found");

                    JOptionPane.showMessageDialog(null,"Login Successful:

＆＃34; + s1）;

                    break mainLoop;

                }


            }
            JOptionPane.showMessageDialog(null,"Wrong Username/Password");



        }   

        catch(Exception exc)

        {
            exc.printStackTrace();

        }

    }

}



public void windowClosing(WindowEvent e) 

{  

    dispose();  

}

public void windowActivated(WindowEvent e) {}

public void windowClosed(WindowEvent e) {}

public void windowDeactivated(WindowEvent e) {}

public void windowDeiconified(WindowEvent e) {}

public void windowIconified(WindowEvent e) {}

public void windowOpened(WindowEvent e) {}

} #Edit： - 对不起，我忘了提供创建帐户页面，这就是问题所在。能不能请你通过它？

Answer 1

你的一些代码不在代码块中，所以很难读，但你加载了驱动程序类吗？

String url="jdbc:mysql://localhost:3306/database1";
String userName="root";
String password="Newyear2016!";
try {

    Class.forName("com.mysql.jdbc.Driver").newInstance();
    Connection con=DriverManager.getConnection(url,username,password);

用户访问被拒绝＆＃39; root＆＃39; localhost＆＃39; （在JAVA中使用密码：YES）

1 个答案: