方法调用的问题

Question

我加上stream.close()后我的程序不能停下来，一直在运行，这是为什么，上面的问题我好像知道了，不过还请高手指教

Answer 1

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;public class FileLister extends Frame {
TextArea text;
public FileLister(){
addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){ dispose();}
});text=new TextArea(" ",24,80);
text.setFont(new Font("MonoSpaced",Font.PLAIN,12));
text.setEditable(false);
this.add("Center",text);Panel p=new Panel();
p.setLayout(new FlowLayout(FlowLayout.RIGHT,10,5));
this.add(p,"South");this.pack();}public void getUrl(){
try{
URL url=new URL("http://www.sina.com.cn/");
String in;
DataInputStream stream=new DataInputStream(url.openStream());
while((in=stream.readLine())!=null){
text.append(in);
text.setCaretPosition(0);
}
}catch(MalformedURLException e){
System.out.println("MalformedURLException:"+e);
}catch(IOException e){
System.out.println("IOException:"+e);
}
}public static void main(String [] args){
FileLister f=new FileLister();
f.addWindowListener(new WindowAdapter(){
public void windowClosed(WindowEvent e){ System.exit(0);}
});f.show();
f.getUrl();
}}
此程序没问题给分吧

Answer 2

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;public class FileLister extends Frame {
TextArea text;
public FileLister(){
addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){ dispose();}
});text=new TextArea(" ",24,80);
text.setFont(new Font("MonoSpaced",Font.PLAIN,12));
text.setEditable(false);
this.add("Center",text);Panel p=new Panel();
p.setLayout(new FlowLayout(FlowLayout.RIGHT,10,5));
this.add(p,"South");this.pack();}public void getUrl(){
try{
URL url=new URL("http://www.sina.com.cn/");
String in;
DataInputStream stream=new DataInputStream(url.openStream());
while((in=stream.readLine())!=null){
text.append(in);
text.setCaretPosition(0);
}
}catch(MalformedURLException e){
System.out.println("MalformedURLException:"+e);
}catch(IOException e){
System.out.println("IOException:"+e);
}
}public static void main(String [] args){
FileLister f=new FileLister();
f.addWindowListener(new WindowAdapter(){
public void windowClosed(WindowEvent e){ System.exit(0);}
});f.show();
f.getUrl();
}}
此程序没问题给分吧

Answer 3

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;public class FileLister extends Frame {
TextArea text;
public FileLister(){
addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){ dispose();}
});text=new TextArea(" ",24,80);
text.setFont(new Font("MonoSpaced",Font.PLAIN,12));
text.setEditable(false);
this.add("Center",text);Panel p=new Panel();
p.setLayout(new FlowLayout(FlowLayout.RIGHT,10,5));
this.add(p,"South");this.pack();}public void getUrl(){
try{
URL url=new URL("http://www.sina.com.cn/");
String in;
DataInputStream stream=new DataInputStream(url.openStream());
while((in=stream.readLine())!=null){
text.append(in);
text.setCaretPosition(0);
}
}catch(MalformedURLException e){
System.out.println("MalformedURLException:"+e);
}catch(IOException e){
System.out.println("IOException:"+e);
}
}public static void main(String [] args){
FileLister f=new FileLister();
f.addWindowListener(new WindowAdapter(){
public void windowClosed(WindowEvent e){ System.exit(0);}
});f.show();
f.getUrl();
}}
此程序没问题给分吧