java读取网络上的xml

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

public class SourceViewer {
  public static void main (String[] args) {
    if  (args.length > 0) {
      try {
        //Open the URL for reading

        URL u = new URL(args[0]);

        InputStream in = u.openStream( );

        // buffer the input to increase performance 

        in = new BufferedInputStream(in);       

        // chain the InputStream to a Reader

        Reader r = new InputStreamReader(in);

        int c;

        while ((c = r.read( )) != -1) {

          System.out.print((char) c);

        } 

      }

      catch (MalformedURLException ex) {

        System.err.println(args[0] + " is not a parseable URL");

      }

      catch (IOException ex) {

        System.err.println(ex);

      }



    } //  end if



  } // end main


} // end SourceViewer



验证url是否存在

	//读取服务器xml数据
     URL u = new URL("http://www.baidu.com");
	
     URLConnection conn = null;
		try {
			conn = u.openConnection();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} 


  
  String   strs=conn.getHeaderField(0); 
  if   (strs.indexOf( "OK")> 0) 
  { 
          System.out.println("url正常! "); 
} else{
      
         System.out.println("url不存在! ")
}