android - Java.lang.NoClassDefFoundError : Failed resolution of: Lorg/apache/http/entity/ContentType;

Question

您好，我使用 android studio，想要将图像上传到 RoR 服务器。但是，当我按下上传按钮时，我收到此错误:

FATAL EXCEPTION: AsyncTask #1
Process: com.example.myapplicationcamera, PID: 11616
java.lang.RuntimeException: An error occurred while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:309)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.lang.NoClassDefFoundError: Failed resolution of: Lorg/apache/http/entity/ContentType;
at org.apache.http.entity.mime.content.FileBody.<init>(FileBody.java:89)
at com.example.myapplicationcamera.UploadActivity$UploadFileToServer.uploadFile(UploadActivity.java:176)
at com.example.myapplicationcamera.UploadActivity$UploadFileToServer.doInBackground(UploadActivity.java:153)
at com.example.myapplicationcamera.UploadActivity$UploadFileToServer.doInBackground(UploadActivity.java:131)
at android.os.AsyncTask$2.call(AsyncTask.java:295)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.lang.ClassNotFoundException: Didn't find class "org.apache.http.entity.ContentType" on path: DexPathList[[dex file "/data/data/com.example.myapplicationcamera/files/instant-run/dex/slice-support-annotations-23.4.0_eb978a40b695cbacc3760b03a82ff4d263be66cd-classes.dex", dex file "/data/data/com.example.myapplicationcamera/files/instant-run/dex/slice-slice_9-classes.dex", dex file "/data/data/com.example.myapplicationcamera/files/instant-run/dex/slice-slice_8-classes.dex", dex file "/data/data/com.example.myapplicationcamera/files/instant-run/dex/slice-slice_7-classes.dex", dex file "/data/data/com.example.myapplicationcamera/files/instant-run/dex/slice-slice_6-classes.dex", dex file "/data/data/com.example.myapplicationcamera/files/instant-run/dex/slice-slice_5-classes.dex", dex file "/data/data/com.example.myapplicationcamera/files/instant-run/dex/slice-slice_4-classes.dex", dex file "/data/data/com.example.myapplicationcamera/files/instant-run/dex/slice-slice_3-classes.dex", dex file "/data/data/com.example.myapplicationcamera/files/instant-run/dex/slice-slice_2-classes.dex", dex file "/data/data/com.example.myapplicationcamera/files/instant-run/dex/slice-slice_1-classes.dex", dex file "/data/data/com.example.myapplicationcamera/files/instant-run/dex/slice-slice_0-classes.dex", dex file "/data/data/com.example.myapplicationcamera/files/instant-run/dex/slice-internal_impl-23.4.0_b87f1f72ec1c9dcbc144d1d0504d45070305661a-classes.dex", dex file "/data/data/com.example.myapplicationcamera/files/instant-run/dex/slice-httpmime-4.3.5_e1f92e9669775764ad0bd3fef73fa0c37469b115-classes.dex", dex file "/data/data/com.example.myapplicationcamera/files/instant-run/dex/slice-com.android.support-support-vector-drawable-23.4.0_6c8fdbed5ab41e288837ace225df060c2da9979a-classes.dex", dex file "/data/data/com.example.myapplicationcamera/files/instant-run/dex/slice-com.android.support-support-v4-23.4.0_31bc06bad02045a071c034877ff069663b43a147-classes.dex", dex file "/data/data/com.example.myapplicationcamera/files/instant-run/dex/slice-com.android.support-appcompat-v7-23.4.0_85f3ceda35b43aaa8f8d9ba7878a3e38fde53a74-classes.dex", dex file "/data/data/com.example.myapplicationcamera/files/instant-run/dex/slice-com.android.support-animated-vector-drawable-23.4.0_03c3e23d10520277fe339d24e7aea8b4848d806b-classes.dex"],nativeLibraryDirectories=[/data/app/com.example.myapplicationcamera-1/lib/arm64, /vendor/lib64, /system/lib64]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
at com.android.tools.fd.runtime.IncrementalClassLoader$DelegateClassLoader.findClass(IncrementalClassLoader.java:90)
at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
at java.lang.ClassLoader.

这是我的 Activity 代码

import android.Manifest;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.ActivityCompat;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.VideoView;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.entity.mime.content.StringBody;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;

import org.apache.http.entity.ContentType;

import java.io.File;
import java.io.IOException;

import com.example.myapplicationcamera.AndroidMultiPartEntity.ProgressListener;

public class UploadActivity extends Activity {
    // LogCat tag
    private static final String TAG = MainActivity.class.getSimpleName();

    private ProgressBar progressBar;
    private String filePath = null;
    private TextView txtPercentage;
    private ImageView imgPreview;
    private VideoView vidPreview;
    private Button btnUpload;
    long totalSize = 0;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_upload);
        txtPercentage = (TextView) findViewById(R.id.txtPercentage);
        btnUpload = (Button) findViewById(R.id.btnUpload);
        progressBar = (ProgressBar) findViewById(R.id.progressBar);
        imgPreview = (ImageView) findViewById(R.id.imgPreview);
        vidPreview = (VideoView) findViewById(R.id.videoPreview);

        // Changing action bar background color
     //   getActionBar().setBackgroundDrawable(
       //        new ColorDrawable(Color.parseColor(getResources().getString(
          //             R.string.ColorRed))));

        // Receiving the data from previous activity
        Intent i = getIntent();

        // image or video path that is captured in previous activity
        filePath = i.getStringExtra("filePath");

        // boolean flag to identify the media type, image or video
        boolean isImage = i.getBooleanExtra("isImage", true);

        if (filePath != null) {
            // Displaying the image or video on the screen
            previewMedia(isImage);
        } else {
            Toast.makeText(getApplicationContext(),
                    "Sorry, file path is missing!", Toast.LENGTH_LONG).show();
        }

        btnUpload.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // uploading the file to server
                new UploadFileToServer().execute();
            }
        });

    }

    /**
     * Displaying captured image/video on the screen
     * */
    private void previewMedia(boolean isImage) {
        // Checking whether captured media is image or video
        if (isImage) {
            imgPreview.setVisibility(View.VISIBLE);
            vidPreview.setVisibility(View.GONE);
            // bimatp factory
            BitmapFactory.Options options = new BitmapFactory.Options();

            // down sizing image as it throws OutOfMemory Exception for larger
            // images
            options.inSampleSize = 8;


            final Bitmap bitmap = BitmapFactory.decodeFile(filePath, options);

            imgPreview.setImageBitmap(bitmap);
        } else {
            imgPreview.setVisibility(View.GONE);
            vidPreview.setVisibility(View.VISIBLE);
            vidPreview.setVideoPath(filePath);
            // start playing
            vidPreview.start();
        }
    }

    /**
     * Uploading the file to server
     * */
    private class UploadFileToServer extends AsyncTask<Void, Integer, String> {
        @Override
        protected void onPreExecute() {
            // setting progress bar to zero
            progressBar.setProgress(0);
            super.onPreExecute();
        }

        @Override
        protected void onProgressUpdate(Integer... progress) {
            // Making progress bar visible
            progressBar.setVisibility(View.VISIBLE);

            // updating progress bar value
            progressBar.setProgress(progress[0]);

            // updating percentage value
            txtPercentage.setText(String.valueOf(progress[0]) + "%");
        }

        @Override
        protected String doInBackground(Void... params) {
            return uploadFile();
        }

        @SuppressWarnings("deprecation")
        private String uploadFile() {
            String responseString = null;

            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httppost = new HttpPost(Config.FILE_UPLOAD_URL);

            try {
                AndroidMultiPartEntity entity = new AndroidMultiPartEntity(
                        new ProgressListener() {

                            @Override
                            public void transferred(long num) {
                                publishProgress((int) ((num / (float) totalSize) * 100));
                            }
                        });

                File sourceFile = new File(filePath);

                // Adding file data to http body
                entity.addPart("image", new FileBody(sourceFile));

                // Extra parameters if you want to pass to server
                entity.addPart("website",
                        new StringBody("www.androidhive.info"));
                entity.addPart("email", new StringBody("abc@gmail.com"));

                totalSize = entity.getContentLength();
                httppost.setEntity(entity);

                // Making server call
                HttpResponse response = httpclient.execute(httppost);
                HttpEntity r_entity = response.getEntity();

                int statusCode = response.getStatusLine().getStatusCode();
                if (statusCode == 200) {
                    // Server response
                    responseString = EntityUtils.toString(r_entity);
                } else {
                    responseString = "Error occurred! Http Status Code: "
                            + statusCode;
                }

            } catch (ClientProtocolException e) {
                responseString = e.toString();
            } catch (IOException e) {
                responseString = e.toString();
            }

            return responseString;

        }

        @Override
        protected void onPostExecute(String result) {
            Log.e(TAG, "Response from server: " + result);

            // showing the server response in an alert dialog
            showAlert(result);

            super.onPostExecute(result);
        }

    }

    /**
     * Method to show alert dialog
     * */
    private void showAlert(String message) {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setMessage(message).setTitle("Response from Servers")
                .setCancelable(false)
                .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        // do nothing
                    }
                });
        AlertDialog alert = builder.create();
        alert.show();
    }


}

这是我的 gradle 导入:

android {
    compileSdkVersion 23
    buildToolsVersion "24.0.2"
    useLibrary  'org.apache.http.legacy'


    packagingOptions {
        exclude 'META-INF/DEPENDENCIES'
    }

    defaultConfig {
        applicationId "com.example.myapplicationcamera"
        minSdkVersion 22
        targetSdkVersion 23
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:23.4.0'
    // compile('org.apache.httpcomponents:httpcore:4.3')
    compile files('libs/commons-io-2.4.jar')
    compile files('libs/fluent-hc-4.3.1.jar')
    compile files('libs/httpcore-4.3.jar')
    compile files('libs/httpmime-4.3.1.jar')
    compile files('libs/picasso-2.1.1.jar')
}

我在这个问题上坐了几个小时，但互联网上没有解决方案。有人有想法吗？

Answer 1

这确实正如异常所说，类加载器找不到该类。我可以建议几件事:

1. 关闭项目，关闭工作室，打开并重试。

2. 看看你的 Android 安装中是否确实有 org/apache 等。如果您有 jar 文件，则可以使用 jar tvfwhatever.jar 列出内容。将是一个很长的列表，所以 jar tvfwhatever.jar | grep apache