详解Java编程中统一资源定位符URL的相关使用

  URL(String s)

URL myURL;
try {
  myURL = new URL(“http://www.weixueyuan.net:80/”);
}catch(MalformedURLException e){
  System.out.println(“有错的URL:”+url+e);
}

  URL mu = new URL(“http://www.sun.com/”);//先要创建一个URL对象
  URLConnection muC = mu.openConnection();//获得URLConnection对象

  dis.close();

import java.net.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.javax.swing.*;
public class Example10_2{
  public static void main(String args[]){
    new downNetFile();
  }
}
class DownNetFile extends JFrame implements ActionListener{
  JTextFileld infield = new JTextField(30);
  JTextarea showArea = new JTextArea();
  JButton b = new JButton(“download”);JPanel p = new JPanel();
  DownNetFile(){
    super(“read network text file application”);
    Container con = this.getContentPane();
    p.add(infield);p.add(b);
    JScrollPane jsp = new JScrollPane(showArea);
    b.addActionListener(this);
    con.add(p,”North”);con.add(jsp,”Center”);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(500,400);setVisible(true);
  }
  public void actionPerformed(ActionEvent e){
    readByURL(infield.getText());
  }
  public void readByURL(String urlName){
    try{
      URL url = new URL(urlName);//由网址创建URL对象
      URLConnection tc = url.openConnectin();//获得URLConnection对象
      tc.connect();//设置网络连接
      InptStreamReader in = new InputStreamReader(tc.getInputStream());
      BufferedReader dis = new BufferedReader(in);//采用缓冲式输入
      String inline;
      while((inline = dis.readLine())!=null){
        showArea.append(inline +”\n”);
      }
      dis.close();//网上资源使用结束后，数据流及时关闭
    }catch(MalformedURLException e){
      e.printStackTrace();
    }
    catch(IOException e){e.printStacktrace();}
    /*访问网上资源可能产生MalformedURLException和IOException异常*/
  }
}