异常：引起：java.lang.NullPointerException：asset

Question

I am reading the .OBJ file which is in asset folder. But I am getting exception while reading the file. Even I debug the project on eclipse but I could find the reason for this.

Please help me

Thanks in advance.

/**
 * Load Object Asynchronous.
 * @author Ajay
 */
private class ObjLoaderAsync extends AsyncTask<Void, Void, Void> {

    private ProgressDialog progressDialog;

    @Override
    protected void onPreExecute() {
        try {
            progressDialog = new ProgressDialog(localContext);
            progressDialog.setTitle(localContext
                    .getString(R.string.app_name));
            progressDialog.setMessage(localContext
                    .getString(R.string.please_wait));
            progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
            progressDialog.setCancelable(true);
            progressDialog.show();
        } catch (Exception e) {
        }
    }

    @Override
    protected Void doInBackground(Void... arg0) {
        try {
            mr[getCurrentPosition()] = new ModelRenderer(localContext,
                    localContext.getAssets().open(RendererView.objName));
        } catch (java.io.IOException e) {
            Log.v("DemoRendererView", "loading model: " + e);
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void param) {
        try {
            progressDialog.cancel();
        } catch (Exception e) {

        }
    }
}

public ModelRenderer(Context paramContext, InputStream localFileInputStream) throws FileNotFoundException {
    ModelStaticClassTransfer.value = -777.0F;
    while (true) {
        try {
            i = localFileInputStream.read();
            if (i != -1)
                continue;
            localFileInputStream.close();
            if ((char) i == 'v') {
                i = localFileInputStream.read();
                if ((char) i != ' ')
                    continue;
                this.verticeCounter = (1 + this.verticeCounter);
                continue;
            }
            if ((char) i == 'f') {
                i = localFileInputStream.read();
                if ((char) i != ' ')
                    continue;
                this.indexCounter = (1 + this.indexCounter);
                continue;
            }
            int j = localFileInputStream.read();
            i = j;
        } catch (IOException localIOException) {
            localIOException.printStackTrace();
            return;
        }
    }
}

Error Trace

09-12 12:54:57.516: E/AndroidRuntime(29949): FATAL EXCEPTION: AsyncTask #2
09-12 12:54:57.516: E/AndroidRuntime(29949): java.lang.RuntimeException: An error occured while executing doInBackground()
09-12 12:54:57.516: E/AndroidRuntime(29949):    at android.os.AsyncTask$3.done(AsyncTask.java:278)
09-12 12:54:57.516: E/AndroidRuntime(29949):    at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
09-12 12:54:57.516: E/AndroidRuntime(29949):    at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
09-12 12:54:57.516: E/AndroidRuntime(29949):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
09-12 12:54:57.516: E/AndroidRuntime(29949):    at java.util.concurrent.FutureTask.run(FutureTask.java:137)
09-12 12:54:57.516: E/AndroidRuntime(29949):    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208)
09-12 12:54:57.516: E/AndroidRuntime(29949):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
09-12 12:54:57.516: E/AndroidRuntime(29949):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
09-12 12:54:57.516: E/AndroidRuntime(29949):    at java.lang.Thread.run(Thread.java:856)
09-12 12:54:57.516: E/AndroidRuntime(29949): Caused by: java.lang.NullPointerException: asset
09-12 12:54:57.516: E/AndroidRuntime(29949):    at android.content.res.AssetManager.readAssetChar(Native Method)
09-12 12:54:57.516: E/AndroidRuntime(29949):    at android.content.res.AssetManager.access$200(AssetManager.java:35)
09-12 12:54:57.516: E/AndroidRuntime(29949):    at android.content.res.AssetManager$AssetInputStream.read(AssetManager.java:548)
09-12 12:54:57.516: E/AndroidRuntime(29949):    at com.amplimesh.models.ModelRenderer.<init>(ModelRenderer.java:64)
09-12 12:54:57.516: E/AndroidRuntime(29949):    at com.amplimesh.models.ModelGLRenderer$ObjLoaderAsync.doInBackground(ModelGLRenderer.java:138)
09-12 12:54:57.516: E/AndroidRuntime(29949):    at com.amplimesh.models.ModelGLRenderer$ObjLoaderAsync.doInBackground(ModelGLRenderer.java:1)
09-12 12:54:57.516: E/AndroidRuntime(29949):    at android.os.AsyncTask$2.call(AsyncTask.java:264)
09-12 12:54:57.516: E/AndroidRuntime(29949):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
09-12 12:54:57.516: E/AndroidRuntime(29949):    ... 5 more

Answer 1

I think you are mistaken with the meaning of the continue keyword. This keyword means that the loop jumps immediately to the next iteration without executing the rest of the code in the loop block.

In your case, it means that this code

i = localFileInputStream.read();
if (i != -1)
    continue;
localFileInputStream.close();
if ((char) i == 'v') {
    i = localFileInputStream.read();

closes the inputStream, and then tries to read from it. You algorithm is not very clear because of all the continues, so I can't really tell you how to fix that.

Answer 2

 @Override
    protected void onPostExecute(Void param) {
        try {
            mr[getCurrentPosition()] = new ModelRenderer(localContext,
                    localContext.getAssets().open(RendererView.objName));
             dialog.cancle();
        } catch (java.io.IOException e) {
            Log.v("DemoRendererView", "loading model: " + e);
        }
    }

please check this...

Answer 3

you start with

try {
        i = localFileInputStream.read();
        if (i != -1)
            continue;
        localFileInputStream.close();

so, you are closing the stream and after that you are trying to read again from it. Also you are running this inside an infinite loop and exit from it only in a the catch section. Consider closing the stream after you are done reading it.