Question

报错：Exception in thread "main" java.lang.Error: Unresolved compilation problem: 求指导啊。

import java.awt.*;import javax.swing.*;
public class BorderJButton extends JFrame{
public BorderJButto{ //Syntax error on token "public",
// class expected after this token

add(new Button("North"),BorderLayout.NORTH);
add(new Button("South"),BorderLayout.SOUTH);
add(new Button("East"),BorderLayout.EAST);
add(new Button("West"),BorderLayout.WEST);
add(new Button("Center"),BorderLayout.CENTER);
}

public static void main(String[] args){
BorderJButton frame=new BorderJButton();
frame.setTitle("测试BorderLayout");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(300, 150);
frame.setVisible(true);
}
}

Answer 1

首先，第三行的public BorderJButto{当中应该少了个字母还有一个括号，应该是
public BorderJButtom(){
另外，最大的问题是构造方法中，添加按钮时是new JButton();
你的构造方法中少了一个J

Answer 2

你这个构造方法连括号都没有 编译肯定会有问题 发出来的方法名也不对

public BorderJButton()
{
}

Answer 3

改成这样：
import java.awt.*;
import javax.swing.*;
public class BorderJButton extends JFrame {
public BorderJButton() {
// Syntax error on token "public",
// class expected after this token
add(new Button("North"), BorderLayout.NORTH);
add(new Button("South"), BorderLayout.SOUTH);
add(new Button("East"), BorderLayout.EAST);
add(new Button("West"), BorderLayout.WEST);
add(new Button("Center"), BorderLayout.CENTER);
}
public static void main(String[] args) {
BorderJButton frame = new BorderJButton();
frame.setTitle("测试BorderLayout");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(300, 150);
frame.setVisible(true);
}
}

Answer 4

构造方法没括号，名字末尾也差个n