Question

我需要将我正在开发的应用程序中的图像上传到服务器，并且我想知道如何使用Google Volley开发Multipart Request来加载图像。

由于

Answer 1

我有一个按Google Volley上传图片的示例。看看：

package net.colaborativa.exampleapp.api;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.nio.charset.Charset;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.apache.http.entity.ContentType;
import org.apache.http.entity.mime.HttpMultipartMode;
import org.apache.http.entity.mime.MultipartEntityBuilder;

import com.android.volley.AuthFailureError;
import com.android.volley.NetworkResponse;
import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.Response.ErrorListener;
import com.android.volley.Response.Listener;
import com.android.volley.VolleyLog;
import com.android.volley.toolbox.HttpHeaderParser;

public class PhotoMultipartRequest<T> extends Request<T> {


private static final String FILE_PART_NAME = "file";

private MultipartEntityBuilder mBuilder = MultipartEntityBuilder.create();
private final Response.Listener<T> mListener;
private final File mImageFile;
protected Map<String, String> headers;

public PhotoMultipartRequest(String url, ErrorListener errorListener, Listener<T> listener, File imageFile){
    super(Method.POST, url, errorListener);

    mListener = listener;
    mImageFile = imageFile;

    buildMultipartEntity();
}

@Override
public Map<String, String> getHeaders() throws AuthFailureError {
    Map<String, String> headers = super.getHeaders();

    if (headers == null
            || headers.equals(Collections.emptyMap())) {
        headers = new HashMap<String, String>();
    }

    headers.put("Accept", "application/json");

    return headers;
}

private void buildMultipartEntity(){
    mBuilder.addBinaryBody(FILE_PART_NAME, mImageFile, ContentType.create("image/jpeg"), mImageFile.getName());
    mBuilder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
    mBuilder.setLaxMode().setBoundary("xx").setCharset(Charset.forName("UTF-8"));
}

@Override
public String getBodyContentType(){
    String contentTypeHeader = mBuilder.build().getContentType().getValue();
    return contentTypeHeader;
}

@Override
public byte[] getBody() throws AuthFailureError{
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    try {
        mBuilder.build().writeTo(bos);
    } catch (IOException e) {
        VolleyLog.e("IOException writing to ByteArrayOutputStream bos, building the multipart request.");
    }

    return bos.toByteArray();
}

@Override
protected Response<T> parseNetworkResponse(NetworkResponse response) {
    T result = null;
    return Response.success(result, HttpHeaderParser.parseCacheHeaders(response));
}

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

你可以像这样使用它：

RequestQueue mQueue = Volley.newRequestQueue(context);
PhotoMultipartRequest imageUploadReq = new PhotoMultipartRequest(url, ErrorListener, Listener, imageFile);
mQueue.add(imageUploadReq);

我希望这些代码会激励你。

Answer 2

@silverknight的答案有效，但是，我还必须在build.gradle中添加以下内容来解决httpcomponents依赖项：

android {

    ...

    // have to exclude these otherwise you'll get:
    // Error:Gradle: Execution failed for task: ... com.android.builder.packaging.DuplicateFileException: ...
    packagingOptions {
        exclude 'META-INF/NOTICE'
        exclude 'META-INF/LICENSE'
        exclude 'META-INF/DEPENDENCIES'
    }
}    

dependencies {

    ...

    compile 'com.android.volley:volley:1.0.0'
    compile('org.apache.httpcomponents:httpmime:4.3.6') {
        exclude module: 'httpclient'
    }
    compile 'org.apache.httpcomponents:httpclient-android:4.3.5.1'
}

注意：请勿使用org.apache.httpcomponents：httpclient

您应该避免使用标准版'org.apache.httpcomponents:httpclient:4.5.2'

如果您尝试：

android {

    ...

}

dependencies {

    ...

    compile 'com.android.volley:volley:1.0.0'
    compile 'org.apache.httpcomponents:httpcore:4.4.4'
    compile 'org.apache.httpcomponents:httpmime:4.5.2'
    compile('org.apache.httpcomponents:httpclient:4.5.2'
}

你会得到：

java.lang.NoSuchFieldError: No static field INSTANCE of type Lorg/apache/http/message/BasicHeaderValueFormatter; in class Lorg/apache/http/message/BasicHeaderValueFormatter; or its superclasses (declaration of 'org.apache.http.message.BasicHeaderValueFormatter' appears in /system/framework/ext.jar)

或类似于现有评论的内容[1] [2] [3]。

根据this SO answer

，您应该使用httpclient的Android端口

注意：使用org.apache.httpcomponents：httpmime：4.3.6

您使用org.apache.httpcomponents:httpmime:4.3.6，您无法超越版本4.3.x。例如，您可能想要使用最新版本的httpmime，在撰写本文时4.5.2：

android {

    ...

}

dependencies {

    ...

    compile('org.apache.httpcomponents:httpmime:4.5.2') {
        exclude module: 'httpclient'
    }
    compile 'org.apache.httpcomponents:httpclient-android:4.3.5.1'

使用此配置，您将在调用PhotoMultipartRequest时获得以下内容：

java.lang.NoSuchMethodError: No static method create(Ljava/lang/String;[Lorg/apache/http/NameValuePair;)Lorg/apache/http/entity/ContentType; in class Lorg/apache/http/entity/ContentType; or its super classes (declaration of 'org.apache.http.entity.ContentType' appears in /xxx/base.apk)

使用Google Volley上传图片

2 个答案: