如何從給定的代碼中刪除I/O異常

Question

import java.io.*; 
import java.awt.*; 
import java.awt.event.*; 
import java.applet.Applet; 
import java.awt.Graphics; 
import java.awt.Color; 


    public class MyGraphic5 extends java.applet.Applet implements ActionListener 
    { 

     boolean go =false; 
      int x, oldx, y, oldy; 
      double angle; 

    Button drawButton =new Button("Draw"); 


     public void init() 
     { 
       add(drawButton); 
       drawButton.addActionListener(this); 
     } 
    public void paint(Graphics screen) 
     { 
      resize(500,500); 
      int x,y, oldx, oldy; 
      double i=0; 
      double a=0; 
      double b=0; 
      oldx=250; 
      oldy=250; 
      double ang=0; 
      //oldx=(int)(a*Math.cos(i)+250); 
      //oldy=(int)(b*Math.sin(i)+250); 
      double angle; 
      x=1; 
      if (go==true) 
      { 
      for (i=0; i<800; i=i+1) 
      { 
       //screen.drawOval(175-i,80,i*2+10,10+i); //(x1,y1,width,height) 
       a=a+.5; 
       b=b+.5; 
       ang=ang+.8; 
       x=(int)(a*Math.cos(ang)+250); 
       y=(int)(b*Math.sin(ang)+250); 
       screen.drawLine(x,y, oldx, oldy); 
       oldx=x; 
       oldy=y; 
       pause(1); 
      } 

      } 
     } 
     public void actionPerformed(ActionEvent event) 
     { 

       Object source = event.getSource(); 
       if (source.equals(drawButton)) 
       { 
        System.out.println("hi"); 
        go=true; 
        repaint(); 
       } 

      } 

     void pause(int time) 
     { 
       try { 
        Thread.sleep(time); 
       } catch (InterruptedException e) { } 
      } 

    } 

Answer 1

我複製了你的代碼，並且能夠在沒有I/O異常的情況下在appletviewer中編譯和運行它...所以我不知道在哪裏問題是...

Answer 2

該代碼甚至沒有包含任何可能會引起IOException的任何內容。