Java I/O - 如何打开从URL的流并输出其内容

        

import java.net.*;
import java.io.*;

public class MainClass {

  public static void main(String[] args) throws IOException {

    InputStream in = null;
    try {
      URL u = new URL("http://www.w3cschool.cn");
      in = u.openStream();
      for (int c = in.read(); c != -1; c = in.read()) {
        System.out.write(c);
      }
      in.close();
    } 
    catch (MalformedURLException ex) {
      System.err.println("not a URL Java understands.");
    }
    finally {
      if (in != null) in.close();
    }
  }
}