我正在尝试上传我正在使用AsyncTask的文件，应用程序正常运行，直到我点击上传按钮（在UploadActivity.java中定义）应用程序停止。这是logcat。
**注意：**我已经提到了logcat给出的异常行号。
FATAL EXCEPTION: AsyncTask #1
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:299)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
at java.util.concurrent.FutureTask.run(FutureTask.java:239)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
at java.lang.Thread.run(Thread.java:841)
Caused by: java.lang.NoClassDefFoundError: org.apache.commons.io.output.ByteArrayOutputStream
at org.apache.http.entity.mime.HttpMultipart.getTotalLength(HttpMultipart.java:219)
at org.apache.http.entity.mime.MultipartEntity.getContentLength(MultipartEntity.java:150)
at com.example.imtiaz.recognizer.UploadActivity$UploadFileToServer.UploadFile(UploadActivity.java:129)
at com.example.imtiaz.recognizer.UploadActivity$UploadFileToServer.doInBackground(UploadActivity.java:108)
at com.example.imtiaz.recognizer.UploadActivity$UploadFileToServer.doInBackground(UploadActivity.java:90)
at android.os.AsyncTask$2.call(AsyncTask.java:287)
at java.util.concurrent.FutureTask.run(FutureTask.java:234)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
at java.lang.Thread.run(Thread.java:841)
这是UploadActivity.java代码。
public class UploadActivity extends AppCompatActivity {
private static final String TAG = MainActivity.class.getSimpleName();
private ProgressBar progressBar;
private String filePath = null;
private ImageView imgPreview;
private Button btnUpload;
long totalSize = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_upload);
btnUpload = (Button) findViewById(R.id.btnUpload);
progressBar = (ProgressBar) findViewById(R.id.progressBar);
imgPreview = (ImageView) findViewById(R.id.imageView);
// Receiving the data from previous activity
Intent i = getIntent();
filePath = i.getStringExtra("filePath");
// boolean flag to identify the media type,
boolean isImage = i.getBooleanExtra("isImage", true);
if (filePath != null) {
// Displaying the image on the screen
previewMedia(isImage);
} else {
Toast.makeText(getApplicationContext(),
filePath + "Sorry, file path is missing!", Toast.LENGTH_LONG).show();
}
//Creating EventListener.
btnUpload.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// uploading the file to server
new UploadFileToServer().execute();
}
});
}
private void previewMedia(boolean isImage) {
//Checking mediaType is image or not
if (isImage) {
imgPreview.setVisibility(View.VISIBLE);
//Reducing image size.
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 8;
//Bitmaping image .
final Bitmap bitmap = BitmapFactory.decodeFile(filePath, options);
imgPreview.setImageBitmap(bitmap);
}
}
//else give message media type is not image.
private class UploadFileToServer extends AsyncTask<Void, Integer, String>//Line 90
{
@Override
protected void onPreExecute() {
progressBar.setProgress(0);
super.onPreExecute();
}
@Override
protected void onProgressUpdate(Integer... progress) {
//set view to true.
progressBar.setVisibility(View.VISIBLE);
//ProgressBar value.
progressBar.setProgress(progress[0]);
}
@Override
protected String doInBackground(Void... Params) {
//do background task (UploadFile).
return UploadFile();//Line 108
}
@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));
totalSize = entity.getContentLength();//Line 129
httppost.setEntity(entity);
//Making Server calls.
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 Status: " + 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 Response.
showAlert(result);
super.onPostExecute(result);
}
}
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();
}
}
dependencies {
compile fileTree(include: ['*.jar'], dir: 'libs')
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:24.2.0'
compile files('libs/httpclient-4.0.jar')
compile files('libs/httpcore-4.0-alpha5.jar')
compile files('libs/apache-mime4j-0.3.jar')
compile files('libs/commons-io-2.5.jar')}
答案 0 :(得分：0)
您错过了依赖关系：
compile group: 'commons-io', name: 'commons-io', version: '2.5'
答案 1 :(得分：0)
您需要使用common-io jar来解决此问题从Here
下载下载后通过lib文件夹中的jar进入项目，右键单击它（commons-io.jar）并选择Add as Library，这应该可以解决问题。