package com.coderising.download.impl;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.Arrays;
import com.coderising.download.api.Connection;
public class ConnectionImpl implements Connection{
private static final Integer BUFFER_SIZE=1024;
private static URLConnection nc;
private static InputStream inputStream;
ConnectionImpl(URL url){
try {
nc=url.openConnection();
} catch (IOException e) {
e.printStackTrace();
}
}
@SuppressWarnings("resource")
@Override
public byte[] read(int startPos, int endPos) throws IOException {
inputStream=nc.getInputStream();
inputStream.skip(startPos);
byte[] readByte=new byte[BUFFER_SIZE];
int totalLen=endPos-startPos+1;
ByteArrayOutputStream baos = new ByteArrayOutputStream();
while(baos.size()<totalLen){
int len=inputStream.read(readByte);
if(len<0){
break;
}
baos.write(readByte,0, len);
}
if(baos.size() > totalLen){
byte[] data = baos.toByteArray();
return Arrays.copyOf(data, totalLen);
}
return baos.toByteArray();
}
@Override
public int getContentLength() {
return nc.getContentLength() ;
}
@Override
public void close() {
try {
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}