要求如下
当点击登陆按钮的时候，就会自动跳转到聊天界面。
我问了很多人了。请你在修改之后再自己的电脑测试一下能否实现
当点击登陆按钮的时候，就会自动跳转到聊天界面。
package sql;
import java.awt.*;
import java.awt.event.*;
import java.sql.*;

import javax.swing.*;
class liaotian extends JFrame implements ActionListener{
JPanel jpanel1;
TextArea textArea1;
TextField textField3;
JButton jButton1;
liaotian(){
this.setTitle("对话");
this.setSize(600,600);

    jpanel1=new JPanel();
    textArea1=new TextArea(15,15);
    jButton1=new JButton("发送");
    textField3=new TextField(10);
    jpanel1.add(textArea1);
    jButton1.addActionListener(this);
    jpanel1.add(jButton1);jpanel1.add(textField3);
    this.add(jpanel1);
    this.setVisible(true);
}
public void actionPerformed(ActionEvent e) {
     if(e.getSource()==jButton1){
         textArea1.setText(textField3.getText());
         textField3.setText("");
     }}}

public class lianxi2 extends JFrame implements ActionListener{
JPanel jpanel;
Label label1;
TextField textField1;
Label label2;
TextField textField2;
JButton jButton;
static String col11,col12;
public lianxi2(){
super("登陆");
jpanel=new JPanel();
this.setVisible(true);
this.setSize(600,600);
label1=new Label("账号");
textField1=new TextField(15);
label2=new Label("密码");
textField2=new TextField(15);
jButton=new JButton("登陆");

jpanel.add(label1); jpanel.add(textField1);
jpanel.add(label2); jpanel.add(textField2);
jpanel.add(jButton);
this.add(jpanel);

        jButton.addActionListener(this); //给jbutton加上监听

        }

public static void main(String[] args) {
lianxi2 lt = new lianxi2();
lt.setVisible(true);
}

public void actionPerformed(ActionEvent e) {
if(e.getSource()==jButton){
try{
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");//加载数据库驱动
Connection conn=DriverManager.getConnection("jdbc:sqlserver://localhost:1433;Database=denglu","sa","123456");//链接数据库
Statement statement=conn.createStatement();

      ResultSet rs = statement.executeQuery("select * from denglu ");
      while(rs.next()){
              col11= rs.getString("zhanghao");
              col12 = rs.getString("mima");
              if(textField1.getText()==col11){
          if(textField2.getText()==col12){
              liaotian m=new liaotian();

          }
      }    
            }
      conn.close();
      }

catch(Exception ex){
ex.printStackTrace();
}

  }

}}