ConnectionImpl.java

package com.coderising.download.impl;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Arrays;

import com.coderising.download.api.Connection;

public class ConnectionImpl implements Connection{
	
	URL url;
	static final int BUFFER_SIZE = 1024;
	
	 ConnectionImpl(String _url) {
		try {
			url = new URL(_url);
		} catch (MalformedURLException e) {
			
			e.printStackTrace();
		}
		
	}
	
	
	
	
	
	@Override
	public byte[] read(int startPos, int endPos) throws IOException {
		HttpURLConnection httpConn = (HttpURLConnection)url.openConnection();
		httpConn.setRequestProperty("Range", "bytes=" + startPos + "-"+ endPos);
		InputStream  is = httpConn.getInputStream();
		
		byte[] buff = new byte[BUFFER_SIZE];
		int totalLen = endPos-startPos+1;
		
		ByteArrayOutputStream baos= new ByteArrayOutputStream();
		
		while(baos.size()<totalLen){
			int len = is.read(buff);
			if(len<0){
				break;
			}
			baos.write(buff,0,len);
			if(baos.size() > totalLen){
	        	byte[] data = baos.toByteArray();
	        	return Arrays.copyOf(data, totalLen);
			}
		}
	        
			return baos.toByteArray();
	
	}

	@Override
	public int getContentLength() {
		
		 URLConnection con;
			try {
				con = url.openConnection();
				
				return con.getContentLength(); 
				
			} catch (IOException e) {			
				e.printStackTrace();
			}  
	        
			return -1;
	}

	@Override
	public void close() {
		
		
	}

}