Java Swing 绝对布局管理方法，null布局
首先把相关容器的布局方式设为 setLayout(null);
然后调用组件的 setBounds() 方法
设置button的位置为(100,100) 长宽分别为 60，25
jButton.setBounds(new Rectangle(100, 100, 60, 25));
import java.awt.Container;import java.awt.Dimension;import java.awt.Rectangle;import java.awt.Toolkit;import javax.swing.JButton;import javax.swing.JCheckBox;import javax.swing.JComboBox;import javax.swing.JFrame;import javax.swing.JPasswordField;import javax.swing.JTextField;public class Log extends JFrame {public static void main(String[] args) {Log log = new Log();}private JButton btLog;private JTextField tfUser;private JPasswordField tfPwd;private JCheckBox pwdKeep;private JComboBox adminType;public Log() {super("固定资产管理系统");super.setSize(380, 292);super.setVisible(true);super.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);centered(this);btLog = new JButton("登 录");btLog.setBounds(new Rectangle(93, 220, 180, 30));//参数分别是坐标x，y，宽，高this.setLayout(null);//设置布局管理器为空this.add(btLog);tfUser = new JTextField();tfUser.setBounds(new Rectangle(73, 115, 220, 25));this.add(tfUser);tfPwd = new JPasswordField();tfPwd.setBounds(new Rectangle(73, 150, 220, 25));this.add(tfPwd);pwdKeep = new JCheckBox("记住密码");pwdKeep.setBounds(new Rectangle(68, 185, 110, 25));this.add(pwdKeep);adminType = new JComboBox(new String[] { "普通职员", "管理员", "高级管理员" });adminType.setBounds(new Rectangle(183, 185, 100, 25));this.add(adminType);}//布局居中方法public void centered(Container container) {Toolkit toolkit = Toolkit.getDefaultToolkit();Dimension screenSize = toolkit.getScreenSize();int w = container.getWidth();int h = container.getHeight();container.setBounds((screenSize.width - w) / 2,(screenSize.height - h) / 2, w, h);}}