系统登录界面代码实现--Java

最近在学习java语言，关于Swing编程在该例子实现的非常不错。整理完给大家参考。更加深入学习java。后面主机mainframe的实现会在另外一篇发表，还未完成。
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class login extends JPanel {
static final int WIDTH = 300;
static final int HEIGHT = 150;
JFrame loginframe;

public void add(Component c, GridBagConstraints constraints, int x, int y, int w, int h){    constraints.gridx = x;    constraints.gridy = y;    constraints.gridwidth = w;    constraints.gridheight = h;    add(c,constraints);}login(){    //创建界面框架    loginframe = new JFrame("信息管理系统");    //窗口关闭方法    loginframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);    //创建网格布局的对象    GridBagLayout lay = new GridBagLayout();    setLayout(lay);    //添加当前对象到登录界面    loginframe.add(this, BorderLayout.WEST);    loginframe.setSize(WIDTH, HEIGHT);    //实现居中显示的功能    Toolkit kit = Toolkit.getDefaultToolkit();    //获取屏幕的大小对象    Dimension screenSize = kit.getScreenSize();    int width = screenSize.width;    int height = screenSize.height;    int x = (width-WIDTH)/2;    int y = (height - HEIGHT)/2;    loginframe.setLocation(x, y);    JButton ok = new JButton("登录");    JButton cancel = new JButton("取消");    JLabel title = new JLabel("信息系统登录窗口");    JLabel name = new JLabel("用户名");    JLabel password = new JLabel("密码");    //创建用户名和密码的输入框    final JTextField nameinput = new JTextField(15);    final JTextField passwordinput = new JTextField(15);    GridBagConstraints constraints = new GridBagConstraints();    //设置对象constrains的相关属性    constraints.fill = GridBagConstraints.NONE;    constraints.anchor = GridBagConstraints.EAST;    constraints.weightx = 3;    constraints.weighty = 4;    //使用网络组布局设置各个控件位置    add(title, constraints, 0, 0, 4, 1);    add(name, constraints, 0, 1, 1, 1);    add(password, constraints, 0, 2, 1, 1);    add(nameinput ,constraints, 2, 1, 1, 1);    add(passwordinput, constraints, 2, 2, 1, 1);    add(ok, constraints, 0, 3, 1, 1);    add(cancel, constraints, 2, 3, 1, 1);    loginframe.setResizable(false);    loginframe.setVisible(true);    //为“OK”按钮注册事件    ok.addActionListener(new ActionListener(){        public void actionPerformed(ActionEvent Event) {            //获取用户名和密码的输入框内容            String nametext = nameinput.getText();            String passwordtext = passwordinput.getText();            //String str = new String(passwordtext);            boolean x = (nametext.equals("Jason"));            boolean y = (passwordtext.equals("123456"));            boolean z = (x && y);            //登录成功            if(z = true){            loginframe.dispose();            mainframe main = new mainframe();            }            //登录失败            else if (z == false){                nameinput.setText("");                passwordinput.setText("");            }        }    });//为“cancel”按钮注册事件cancel.addActionListener(new ActionListener(){    public void actionPerformed(ActionEvent Event){        loginframe.dispose();        }    });}

}
public class studentlog{
public static void main(String[] args){
login log = new login();
}
}