Question

我试图在隐写术上做一个项目，其中在将信息隐藏在图像中之后，我想将图像发送到PC中的wamp服务器。以下是我用来向wamp服务器发送图像的AsyncTask，其中我获得了致命异常：

private class UploadImage extends AsyncTask<Void, Void, Void> {

Bitmap image;
String name;
ArrayList<NameValuePair> dataToSend = new ArrayList();

public UploadImage(String name){

    String path = Environment.getExternalStorageDirectory().toString();
    path = path+"/stegimg1.png";
    Bitmap SendImg1 = BitmapFactory.decodeFile(path);

    this.image = SendImg1;
    this.name = name;

    //Toast.makeText(getApplicationContext(), "Constructor - UpImg",Toast.LENGTH_SHORT).show();
}

@Override
protected Void doInBackground(Void... arg0) {


    HttpParams httpRequestParams = getHttpRequestParams();
    HttpClient client = new DefaultHttpClient(httpRequestParams);
    HttpPost post = new HttpPost(SERVERADDRESS + "/SavePicture.php");

    try{
        post.setEntity(new UrlEncodedFormEntity(dataToSend));
        client.execute(post);
    }catch(Exception e)
    {
        e.printStackTrace();
    }
    return null; 
}

@Override
protected void onPostExecute(Void result) {
    // TODO Auto-generated method stub

    Toast.makeText(getApplicationContext(), "Image sent to the server",Toast.LENGTH_SHORT).show();
    super.onPostExecute(result);
    //Toast.makeText(getApplicationContext(), "Image Uploaded" , Toast.LENGTH_SHORT).show();
}

@Override
protected void onPreExecute() {

    Toast.makeText(getApplicationContext(), "Inside OnPreEXEC" , Toast.LENGTH_SHORT).show();

    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    image.compress(Bitmap.CompressFormat.PNG, 100, baos);
    String encodedImage = Base64.encodeToString(baos.toByteArray(), Base64.DEFAULT);



    dataToSend.add(new BasicNameValuePair("image", encodedImage));
    dataToSend.add(new BasicNameValuePair("name", name));
    super.onPreExecute();

}

}

我得到的Logcat输出是

05-17 16:45:39.077: E/AndroidRuntime(1860): FATAL EXCEPTION: AsyncTask #1
05-17 16:45:39.077: E/AndroidRuntime(1860): java.lang.RuntimeException: An error occured while executing doInBackground()
05-17 16:45:39.077: E/AndroidRuntime(1860):     at android.os.AsyncTask$3.done(AsyncTask.java:299)
05-17 16:45:39.077: E/AndroidRuntime(1860):     at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
05-17 16:45:39.077: E/AndroidRuntime(1860):     at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
05-17 16:45:39.077: E/AndroidRuntime(1860):     at java.util.concurrent.FutureTask.run(FutureTask.java:239)
05-17 16:45:39.077: E/AndroidRuntime(1860):     at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
05-17 16:45:39.077: E/AndroidRuntime(1860):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
05-17 16:45:39.077: E/AndroidRuntime(1860):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
05-17 16:45:39.077: E/AndroidRuntime(1860):     at java.lang.Thread.run(Thread.java:856)
05-17 16:45:39.077: E/AndroidRuntime(1860): Caused by: java.lang.OutOfMemoryError
05-17 16:45:39.077: E/AndroidRuntime(1860):     at java.lang.String.<init>(String.java:365)
05-17 16:45:39.077: E/AndroidRuntime(1860):     at java.lang.String.<init>(String.java:228)
05-17 16:45:39.077: E/AndroidRuntime(1860):     at android.util.Base64.encodeToString(Base64.java:456)
05-17 16:45:39.077: E/AndroidRuntime(1860):     at com.msrohit.imageselect.MainActivity$UploadImage.doInBackground(MainActivity.java:209)

这里出了什么问题？

Answer 1

Android为每个应用的堆大小设置了硬限制。最正确堆大小限制因设备而异，具体取决于RAM的大小设备总体可用。如果您的应用已到达堆容量和尝试分配更多的内存，它会收到一个的OutOfMemoryError。

您应增加堆大小并缩小图像大小。希望这会有所帮助。

Asynctask

1 个答案: