使用Apache發送Android Volley文件：NoClassDefFoundError：ContentType失敗解決方法

Question

我需要將文件從Android應用上傳到服務器。我使用Volley和創建的類，這有助於與multipart幫助發送數據：

public class MultipartRequest extends Request<String> { 

    MultipartEntityBuilder entity = MultipartEntityBuilder.create(); 
    HttpEntity httpentity; 
    private static final String FILE_PART_NAME = "image "; 

    private final Response.Listener<String> mListener; 
    private final File mFilePart; 
    private final Map<String, String> mStringPart; 

    public MultipartRequest(String url, Response.ErrorListener errorListener, 
          Response.Listener<String> listener, File file, 
          Map<String, String> mStringPart) { 
     super(Method.POST, url, errorListener); 
     mListener = listener; 
     mFilePart = file; 
     this.mStringPart = mStringPart; 
     entity.setMode(HttpMultipartMode.BROWSER_COMPATIBLE); 
     buildMultipartEntity(); 
    } 

    public void addStringBody(String param, String value) { 
     mStringPart.put(param, value); 
    } 

    private void buildMultipartEntity() { 
     entity.addPart(FILE_PART_NAME, new FileBody(mFilePart)); 
     for (Map.Entry<String, String> entry : mStringPart.entrySet()) { 
      entity.addTextBody(entry.getKey(), entry.getValue()); 
     } 
    } 

    @Override 
    public String getBodyContentType() { 
     return httpentity.getContentType().getValue(); 
    } 

    @Override 
    public byte[] getBody() throws AuthFailureError { 
     ByteArrayOutputStream bos = new ByteArrayOutputStream(); 
     try { 
      httpentity = (HttpEntity) entity.build(); 
      httpentity.writeTo(bos); 
     } catch (IOException e) { 
      VolleyLog.e("IOException writing to ByteArrayOutputStream"); 
     } 
     return bos.toByteArray(); 
    } 

    @Override 
    protected Response<String> parseNetworkResponse(NetworkResponse response) { 
     return Response.success("Uploaded", getCacheEntry()); 
    } 

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

我使用Gradle，所以我的依賴關係：

compile 'org.apache.httpcomponents:httpmime:4.5.1' 

試圖實現libs文件夾中的庫，但在項目構建期間遇到問題。 當我做出這樣的要求，我收到：

 java.lang.NoClassDefFoundError: Failed resolution of: Lorg/apache/http/entity/ContentType; 

    Caused by: java.lang.ClassNotFoundException: Didn't find class "org.apache.http.entity.ContentType" on path: DexPathList[[zip file "/data/app/android.demigos.comouts-1/base.apk"], 
nativeLibraryDirectories=[/system/lib, /vendor/lib, system/vendor/lib, system/vendor/lib/egl, system/lib/hw]] 

我的搖籃文件：

android { 
    compileSdkVersion 23 
    buildToolsVersion "23.0.2" 
    useLibrary 'org.apache.http.legacy' 
    defaultConfig { 
     applicationId "android.demigos.comouts" 
     minSdkVersion 15 
     targetSdkVersion 23 
     versionCode 1 
     versionName "1.0" 
     multiDexEnabled true 
    } 
    buildTypes { 
     release { 
      minifyEnabled false 
      proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' 
     } 
    } 
    compileOptions { 
     sourceCompatibility JavaVersion.VERSION_1_7 
     targetCompatibility JavaVersion.VERSION_1_7 
    } 
} 

dependencies { 
    compile fileTree(include: ['*.jar'], dir: 'libs') 
    testCompile 'junit:junit:4.12' 
    ...... 
    compile "org.apache.httpcomponents:httpcore:4.2.4" 
} 

Answer 1

添加到您的build.gradle：

android { 
    ... 
    useLibrary 'org.apache.http.legacy' 
    ... 
} 

，並刪除這條線：

compile 'org.apache.httpcomponents:httpmime:4.5.1'