package com.coderising.download.impl;
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;
class ConnectionImpl implements Connection{
static final int BUFFER_SIZE = 1024;
URL url;
ConnectionImpl(String theUrl) {
try {
url=new URL(theUrl);
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
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();
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 openConnection;
try {
openConnection = url.openConnection();
return openConnection.getContentLength();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return 0;
}
@Override
public void close() {
}
}