package com.m0312.download.impl;
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 com.m0312.download.api.Connection;
public class ConnectionImpl implements Connection{
URLConnection urlCon;
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 {
//只能写出第一部分
byte[] buffer=new byte[endPos-startPos+1];
HttpURLConnection urlCon2 = (HttpURLConnection)url.openConnection();
urlCon2.setRequestProperty("Range", "bytes=" + startPos + "-"
+ endPos);
InputStream is=urlCon2.getInputStream();
//is.skip(startPos);
is.read(buffer, 0, endPos-startPos+1);//因为没有+1,一直是只有三分之一部分
is.close();
return buffer;
/*HttpURLConnection httpConn = (HttpURLConnection)url.openConnection();
httpConn.setRequestProperty("Range", "bytes=" + startPos + "-"
+ endPos);
InputStream is = httpConn.getInputStream();
//is.skip(startPos);
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);
System.out.println("is read length: "+len);
System.out.println("baos.size: "+baos.size());
}
if(baos.size() > totalLen){
byte[] data = baos.toByteArray();
return Arrays.copyOf(data, totalLen);
}
return baos.toByteArray();
*/
/**
* 开始读[0,1603]
开始读[1604,3207]
is read length: 1024
is read length: 1024
baos.size: 1024
baos.size: 1024
开始读[3208,4811]
is read length: 580
baos.size: 1604 ///size会累积,等于度过的所有buffer size
is read length: 1024
baos.size: 1024
is read length: 580
baos.size: 1604
is read length: 580
baos.size: 1604
*/
}
@Override
public int getContentLength() {
return urlCon.getContentLength();
}
@Override
public void close() {
if(urlCon!=null){
//???
}
}
@Override
public URLConnection getUrlCon() {
return urlCon;
}
@Override
public void setUrlCon(URLConnection urlCon) {
this.urlCon = urlCon;
}
}