eclipse 编写JAVA程序 只想编写一个界面,输入账号和密码的,但是出错...答:jLabel1.setText("用户名");jLabel1.setBounds(45, 30, 75, 25);} { jLabel2 = new JLabel();jPanel1.add(jLabel2);jLabel2.setText("密码");jLabel2.setBounds(45, 75, 55, 15);} { username = new JTextField();jPanel1.add(username);username.setBounds(100, 30, 140, 25...