如何在没有 HttpEntity 的情况下使用 Volley 发送多部分请求？

我正在遵循使用齐射发送多部分请求的解决方案如何使用 Android Volley 分割数据 https://stackoverflow.com/questions/18288864/how-to-multipart-data-using-android-volley。但是，从 SDK 22 开始，httpentity 已被弃用，并且在 SDK 23 上被完全删除。

解决方案是使用 openConnection，就像Android 上现在已弃用 HttpEntity，有什么替代方案吗？ https://stackoverflow.com/questions/29150184/httpentity-is-deprecated-on-android-now-whats-the-alternative，但我不知道如何将它用于多部分请求

我已经找到了解决方案（基于Android 中的多部分/表单数据请求：HttpURLConnection 与 OkHttp http://mysecondmemory.weebly.com/android/multipartform-data-requests-in-android-httpurlconnection-vs-okhttp)

这是我的工作示例代码（使用 ASP.Net WebAPI 测试）

多部分活动.java

package com.example.volleyapp;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.support.v4.content.ContextCompat;
import android.view.Menu;
import android.view.MenuItem;

import com.android.volley.AuthFailureError;
import com.android.volley.NetworkResponse;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.example.volleyapp.BaseVolleyRequest;
import com.example.volleyapp.VolleySingleton;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;

public class MultipartActivity extends Activity {

    final Context mContext = this;
    String mimeType;
    DataOutputStream dos = null;
    String lineEnd = "\r\n";
    String boundary = "apiclient-" + System.currentTimeMillis();
    String twoHyphens = "--";
    int bytesRead, bytesAvailable, bufferSize;
    byte[] buffer;
    int maxBufferSize = 1024 * 1024;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_multipart);             

        Drawable drawable = ContextCompat.getDrawable(mContext, R.drawable.ic_action_file_attachment_light);
        Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.PNG, 100, byteArrayOutputStream);
        final byte[] bitmapData = byteArrayOutputStream.toByteArray();
        String url = "http://192.168.1.100/api/postfile";

        mimeType = "multipart/form-data;boundary=" + boundary;

        BaseVolleyRequest baseVolleyRequest = new BaseVolleyRequest(1, url, new Response.Listener<NetworkResponse>() {
            @Override
            public void onResponse(NetworkResponse response) {

            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {

            }
        }) {
            @Override
            public String getBodyContentType() {
                return mimeType;
            }

            @Override
            public byte[] getBody() throws AuthFailureError {
                ByteArrayOutputStream bos = new ByteArrayOutputStream();
                dos = new DataOutputStream(bos);
                try {
                    dos.writeBytes(twoHyphens + boundary + lineEnd);
                    dos.writeBytes("Content-Disposition: form-data; name=\"uploaded_file\";filename=\""
                            + "ic_action_file_attachment_light.png" + "\"" + lineEnd);
                    dos.writeBytes(lineEnd);
                    ByteArrayInputStream fileInputStream = new ByteArrayInputStream(bitmapData);
                    bytesAvailable = fileInputStream.available();

                    bufferSize = Math.min(bytesAvailable, maxBufferSize);
                    buffer = new byte[bufferSize];

                    // read file and write it into form...
                    bytesRead = fileInputStream.read(buffer, 0, bufferSize);

                    while (bytesRead > 0) {
                        dos.write(buffer, 0, bufferSize);
                        bytesAvailable = fileInputStream.available();
                        bufferSize = Math.min(bytesAvailable, maxBufferSize);
                        bytesRead = fileInputStream.read(buffer, 0, bufferSize);
                    }

                    // send multipart form data necesssary after file data...
                    dos.writeBytes(lineEnd);
                    dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);

                    return bos.toByteArray();

                } catch (IOException e) {
                    e.printStackTrace();
                }
                return bitmapData;
            }
        };

        VolleySingleton.getInstance(mContext).addToRequestQueue(baseVolleyRequest);

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_multipart, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

BaseVolleyRequest.java：

package com.example.volleyapp;

import com.android.volley.NetworkResponse;
import com.android.volley.ParseError;
import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.HttpHeaderParser;
import com.google.gson.JsonSyntaxException;


public class BaseVolleyRequest extends Request<NetworkResponse> {

    private final Response.Listener<NetworkResponse> mListener;
    private final Response.ErrorListener mErrorListener;

    public BaseVolleyRequest(String url, Response.Listener<NetworkResponse> listener, Response.ErrorListener errorListener) {
        super(0, url, errorListener);
        this.mListener = listener;
        this.mErrorListener = errorListener;
    }

    public BaseVolleyRequest(int method, String url, Response.Listener<NetworkResponse> listener, Response.ErrorListener errorListener) {
        super(method, url, errorListener);
        this.mListener = listener;
        this.mErrorListener = errorListener;
    }

    @Override
    protected Response<NetworkResponse> parseNetworkResponse(NetworkResponse response) {
        try {
            return Response.success(
                    response,
                    HttpHeaderParser.parseCacheHeaders(response));
        } catch (JsonSyntaxException e) {
            return Response.error(new ParseError(e));
        } catch (Exception e) {
            return Response.error(new ParseError(e));
        }
    }

    @Override
    protected void deliverResponse(NetworkResponse response) {
        mListener.onResponse(response);
    }

    @Override
    protected VolleyError parseNetworkError(VolleyError volleyError) {
        return super.parseNetworkError(volleyError);
    }

    @Override
    public void deliverError(VolleyError error) {
        mErrorListener.onErrorResponse(error);
    }
}