Apache HttpClient 添加字节范围标头？

有谁知道如何在 HTTP 请求中请求字节范围？我希望通过请求下载停止位置的字节范围并从 getContent() 读取其 InputStream 来促进应用程序中下载的恢复。

我尝试迭代标题，但它们为空。来源如下。

import java.io.IOException;
import java.io.InputStream;

import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.util.Log;

/**
 * @author Kevin Kowalewski
 *
 */
public class DownloadClient {
DefaultHttpClient httpClient;
HttpGet httpGet;
HttpResponse httpResponse;
HttpEntity httpEntity;
InputStream httpInputStream;

private static String LOG_TAG = DownloadClient.class.getName();

public DownloadClient(){
    httpClient = new DefaultHttpClient();
    httpGet = new HttpGet("http://cachefly.cachefly.net/100mb.test");
    for (Header header : httpGet.getAllHeaders()){
        Log.d(LOG_TAG, "--> Header: " + header);
    }

    Log.d(LOG_TAG, "--> Header size is: " + httpGet.getAllHeaders().length);
    try {
        httpResponse = httpClient.execute(httpGet);
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    httpEntity = httpResponse.getEntity();
    try {
        httpInputStream = httpEntity.getContent();
    } catch (IllegalStateException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    Log.d(LOG_TAG, "--> StatusLine: " + httpResponse.getStatusLine());
}

public void read(){
    byte[] readBuffer = new byte[32];
    try {
        while (httpInputStream.read(readBuffer) != -1){
            try{Thread.sleep(100);}catch(Exception e){}
            //Log.d(LOG_TAG,"--> Read Bytes: " + new String(readBuffer));
        };
    } catch (IOException e) {
        e.printStackTrace();
    }

}

public void shutdown(){
    httpGet.abort();
    httpClient.getConnectionManager().shutdown();
}

}

Kevin

我可以通过添加以下行来使其工作：

httpGet.addHeader("Range", "bytes=0-0");