httpdownloader.java

来自「相册是J2me MIDLet 的一个demo程序」· Java 代码 · 共 94 行

/*
 *  
 *  Filename:  HttpDownloader.java 
 *  - contains definition of the class HttpDownloader, which has a static method for downloading byte data 
 *  from specified URL. The method is called from DownloadFromURLForm object. 
 *
 *  Application Name: Image Album Demo 
 *  Version: 2.0
 *  Release Date: 27th September, 2002
 *  Author:	Edmund Wong, Application Engineer, Metrowerks Hong Kong
 *
 *
 *  (c) Copyright. 2002. Metrowerks Corp. ALL RIGHTS RESERVED.
 *	This code is provided "AS IS" without warranty of any kind and subject to Metrowerks Sample Application
 *  End User License Agreement. NO EXTERNAL DISTRIBUTION OR COMMERCIALIZATION OF THE SOFTWARE IS PERMITTED 
 *  EXCEPT BY WRITTEN AGREEMENT OF METROWERKS."
 */


import javax.microedition.lcdui.*;
import javax.microedition.io.*;
import java.io.*;


/**
 * 	Class HttpDownloader for downloading byte data from specified URL
 */

public class HttpDownloader {

		
    /**
     * HttpDownloader Constructor
     */
    public HttpDownloader () {
          
        
    }


    /**
     *	Static method for downloading byte data from specified URL 
     */
    public static byte[] httpDownload (String url) throws IOException {
    
    	byte[] downloadedData = null;   // byte data buffer
            
        String responseMessage = null;	// storing repsonse message from server
                           
 		HttpConnection httpConnection = null;	
 		
 		DataInputStream dataInputStream = null;	
 		
 		
 		 		 		           
        try {
        	
        	httpConnection = (HttpConnection)Connector.open(url);
        	
        	//httpConnection.setRequestMethod(HttpConnection.GET);
        	
			// for testing
			responseMessage = httpConnection.getResponseMessage();
			
			System.out.println(httpConnection.getResponseCode());
			
			System.out.println(responseMessage);
			
			dataInputStream = new DataInputStream(httpConnection.openDataInputStream());
							
			downloadedData = new byte[(int)httpConnection.getLength()];
			
			dataInputStream.readFully(downloadedData);
												
        }                        
                    
        finally {	//close the dataInputStream and httpConnection 
        
        if (dataInputStream != null) dataInputStream.close();
        
        if (httpConnection != null) httpConnection.close();
        
        }
        
        return downloadedData;

						
       
    }

    
    

}