ConnectionImpl.java

package impl;

import api.Connection;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class ConnectionImpl implements Connection {

    URL url;

    public ConnectionImpl(String urlString) {
        try {
            url = new URL(urlString);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
    }

    @Override
    public byte[] read(int startPos, int endPos) throws IOException {
        ByteArrayOutputStream baos = null;
        try {
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestProperty("Range", "bytes=" + startPos + "-" + endPos);
            InputStream in = conn.getInputStream();
            baos = new ByteArrayOutputStream();
            int len = 0;
            byte[] buffer = new byte[1024];
            while ((len = in.read(buffer)) != -1) {
                baos.write(buffer, 0, len);
            }
            in.close();
            baos.close();

        } catch (IOException e) {
            e.printStackTrace();
        }
        return baos.toByteArray();
    }

    @Override
    public int getContentLength() {
        HttpURLConnection conn = null;
        try {
            conn = (HttpURLConnection) url.openConnection();
            return conn.getContentLength();
        } catch (IOException e) {
            return -1;
        } finally {
            conn.disconnect();
        }
    }

    @Override
    public void close() {

    }

}