简单程序的Java错误停止编译过程,请提供帮助

2020年3月5日 20点热度 0条评论

我是这里的初学者,但是一段时间以来我一直在处理这个未知的问题。请查看我编写的这个简单程序,并解释为什么它不会为我编译。事情是,我从老师那里复制了这段代码,并且在他的机器上运行良好。然后,当我尝试在计算机上运行示例时,出现13个错误!

这是头等舱:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

class radio extends JFrame{

 private JTextField tf;
 private Font pf;
 private Font bf;
 private Font itf;
 private Font bif;
 private JRadioButton pb;
 private JRadioButton bb;
 private JRadioButton ib;
 private JRadioButton bib;
 private ButtonGroup group;

 public radio(){
  super("raido buttonseses");
  setLayout(new FlowLayout());

  tf = new JTextField("buggedy buggedy boo", 25);
  add(tf);

  pb = new JRadioButton("plain", true);
  bb = new JRadioButton("bold", false);
  ib = new JRadioButton("italic", false);
  bib = new JRadioButton("bold and italic", false);

  add(pb);
  add(bb);
  add(ib);
  add(bib);

  group = new ButtonGroup();
  group.add(pb);
  group.add(bb);
  group.add(ib);
  group.add(bib);


  pf = new Font("Serif", Font.PLAIN, 14);
  bf = new Font("Serif", Font.BOLD, 14);
  itf = new Font("Serif", Font.ITALIC, 14);
  bif = new Font("Serif", Font.BOLD + Font.ITALIC, 14);
  tf.setFont(pf);

  //wait for event to happen pass in font obj to constructor
  pb.addItemListener(new HandlerClass(pf));
  bb.addItemListener(new HandlerClass(bf));
  ib.addItemListener(new HandlerClass(itf));
  bib.addItemListener(new HandlerClass(bif));





 }


  private class HandlerClass implements ItemListener{

  private Font font;
  // font obj gets variable font
  public HandlerClass(Font f){
   font = f;


  }

  //sets font to font obj that was passed in
  public void itemStateChanged(ItemEvent event){
   tf.setFont(font);


}


 }

    }

这是我一直尝试运行的第二个主要类:

import javax.swing.JFrame;

public class radiobutton{
 public static void main(String[] args) {

  radio go = new radio();
  go.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  go.setSize(300,200);
  go.setVisible(true);

 }


}

我知道有人正在看这个,并认为答案是如此明显,但是对于像我这样的初学者来说,答案不是很清楚。这是我尝试编译时返回给我的错误:

javac radiobutton.java
./JFrame.java:1: JFrame is already defined in this compilation unit
import javax.swing.JFrame;
^
radiobutton.java:7: cannot find symbol
symbol  : method setDefaultCloseOperation(int)
location: class radio
            go.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
              ^
radiobutton.java:8: cannot find symbol
symbol  : method setSize(int,int)
location: class radio
            go.setSize(300,200);
              ^
radiobutton.java:9: cannot find symbol
symbol  : method setVisible(boolean)
location: class radio
            go.setVisible(true);
              ^
./JFrame.java:8: cannot find symbol
symbol  : variable EXIT_ON_CLOSE
location: class JFrame
            go.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                                              ^
./radio.java:19: cannot find symbol
symbol  : constructor JFrame(java.lang.String)
location: class JFrame
            super("raido buttonseses");
            ^
./radio.java:20: cannot find symbol
symbol  : method setLayout(java.awt.FlowLayout)
location: class radio
            setLayout(new FlowLayout());
            ^
./radio.java:22: cannot find symbol
symbol  : class JTExtField
location: class radio
            tf = new JTExtField("buggedy buggedy boo", 25);
                     ^
./radio.java:23: cannot find symbol
symbol  : method add(javax.swing.JTextField)
location: class radio
            add(tf);
            ^
./radio.java:30: cannot find symbol
symbol  : method add(javax.swing.JRadioButton)
location: class radio
            add(pb);
            ^
./radio.java:31: cannot find symbol
symbol  : method add(javax.swing.JRadioButton)
location: class radio
            add(bb);
            ^
./radio.java:32: cannot find symbol
symbol  : method add(javax.swing.JRadioButton)
location: class radio
            add(ib);
            ^
./radio.java:33: cannot find symbol
symbol  : method add(javax.swing.JRadioButton)
location: class radio
            add(bib);
            ^
13 errors

我的猜测是,这与java函数导入中的星号有关。我在正确的轨道上吗?感谢您查看这个愚蠢的问题,非常感谢您的帮助。

解决方案如下:

它对我来说编译就很好。

错误可能是这样的:您的源目录中还有另一个名为JFrame.java的文件。删除该文件! JFrame已在API中定义。

错误讯息...

./JFrame.java:1: JFrame is already defined in this compilation unit
import javax.swing.JFrame;

...显示
./JFrame.java
radiobutton在同一包中。

(作为旁注,我要提到的是,根据Java编码约定,您应始终以大写字母开头类名。)