android - 如何在Android中使用 Volley 下载视频文件？

我想使用 Volley 库下载视频。我将 Volley 库用于应用程序中的所有网络调用。

最佳答案

首先，我们需要创建一个扩展Volley Request类的自定义类。要下载文件数据，我们可以创建一个自定义字节数组请求。该字节数组可以转换为将数据写入SDCard的inputstream。以下InputStreamVolleyRequest.java文件显示了如何创建自定义字节数组请求和访问响应 header ，这些 header 稍后将用于创建文件名。

InputStreamVolleyRequest.java

import com.android.volley.AuthFailureError;
import com.android.volley.NetworkResponse;
import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.toolbox.HttpHeaderParser;
import java.util.HashMap;
import java.util.Map;

public class InputStreamVolleyRequest extends Request<byte[]> {
private final Response.Listener<byte[]> mListener;
private Map<String, String> mParams;
//create a static map for directly accessing headers
public Map<String, String> responseHeaders ;

public InputStreamVolleyRequest(int post, String mUrl,Response.Listener<byte[]> listener,
                                Response.ErrorListener errorListener, HashMap<String, String> params) {
    // TODO Auto-generated constructor stub

     super(post, mUrl, errorListener);
     // this request would never use cache.
     setShouldCache(false);
     mListener = listener;
     mParams=params;
}

@Override
protected Map<String, String> getParams()
        throws com.android.volley.AuthFailureError {
    return mParams;
};


@Override
protected void deliverResponse(byte[] response) {
    mListener.onResponse(response);
}

@Override
protected Response<byte[]> parseNetworkResponse(NetworkResponse response) {

    //Initialise local responseHeaders map with response headers received
    responseHeaders = response.headers;

    //Pass the response data here
    return Response.success(response.data, HttpHeaderParser.parseCacheHeaders(response));
}

}

您的 Activity 课.....

import android.os.Environment;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.Response.ErrorListener;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.HurlStack;
import com.android.volley.toolbox.Volley;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;


public class FileDownloadActivity extends ActionBarActivity implements Response.Listener<byte[]>, ErrorListener{
Button btn_download;
InputStreamVolleyRequest request;
int count;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_file_download);
    btn_download =(Button)findViewById(R.id.button);
    btn_download.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            //Change your url below
            String mUrl="http://yoururl.com";
            request = new InputStreamVolleyRequest(Request.Method.GET, mUrl, FileDownloadActivity.this, FileDownloadActivity.this, null);
            RequestQueue mRequestQueue = Volley.newRequestQueue(getApplicationContext(),
                    new HurlStack());
            mRequestQueue.add(request);
        }
    });
}

@Override
public void onResponse(byte[] response) {
    HashMap<String, Object> map = new HashMap<String, Object>();
    try {
        if (response!=null) {

            //Read file name from headers
            String content =request.responseHeaders.get("Content-Disposition")
                    .toString();
            StringTokenizer st = new StringTokenizer(content, "=");
            String[] arrTag = st.toArray();

            String filename = arrTag[1];
            filename = filename.replace(":", ".");
            Log.d("DEBUG::RESUME FILE NAME", filename);

            try{
                long lenghtOfFile = response.length;

                //covert reponse to input stream
                InputStream input = new ByteArrayInputStream(response);
                File path = Environment.getExternalStorageDirectory();
                File file = new File(path, filename);
                map.put("resume_path", file.toString());
                BufferedOutputStream output = new BufferedOutputStream(new FileOutputStream(file));
                byte data[] = new byte[1024];

                long total = 0;

                while ((count = input.read(data)) != -1) {
                    total += count;
                    output.write(data, 0, count);
                }

                output.flush();

                output.close();
                input.close();
            }catch(IOException e){
                e.printStackTrace();

            }
        }
    } catch (Exception e) {
        // TODO Auto-generated catch block
        Log.d("KEY_ERROR", "UNABLE TO DOWNLOAD FILE");
        e.printStackTrace();
    }
}

@Override
public void onErrorResponse(VolleyError error) {
    Log.d("KEY_ERROR", "UNABLE TO DOWNLOAD FILE. ERROR:: "+error.getMessage());
}
}

还有这个StringTokenizer类.....
StringTokenizer.java

关于android - 如何在Android中使用 Volley 下载视频文件？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/39051966/