Android Camera App:java.lang.RuntimeException:无法恢复活动

时间:2015-03-17 13:51:54

标签: android nullpointerexception runtimeexception

我正在开发一个应用程序,使用户可以按下按钮并录制视频,每当他按下停止时,视频都会保存,然后视频的缩略图会显示在ImageView中。这是源代码:

public class Home extends ActionBarActivity {
    private static final int CAPTURE_VIDEO_ACTIVITY_REQUEST_CODE = 200;
    private Uri fileUri;
    public static final int MEDIA_TYPE_VIDEO = 2;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_home);

        Button openCam = (Button) findViewById(R.id.button);


        openCam.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //send request to capture video
                Intent myVideo = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
                //video save file
                fileUri = getOutputMediaFileUri(MEDIA_TYPE_VIDEO);

                myVideo.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
                //set high quality
                myVideo.putExtra(MediaStore.EXTRA_VIDEO_QUALITY, 1);
                //set camera roll to 25sec length
                myVideo.putExtra(MediaStore.EXTRA_DURATION_LIMIT,25);
                //execute intent, camera opens for the user to capture vid
                startActivityForResult(myVideo, CAPTURE_VIDEO_ACTIVITY_REQUEST_CODE);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == CAPTURE_VIDEO_ACTIVITY_REQUEST_CODE) {
            if (resultCode == RESULT_OK) {

            ImageView imgView = (ImageView) findViewById(R.id.imageView);
            TextView tv = (TextView) findViewById(R.id.textView);
            TextView tv2 = (TextView) findViewById(R.id.textView2);

            String path = fileUri.getPath().toString(); <-- line 76

            Bitmap thumb = ThumbnailUtils.createVideoThumbnail(path,
                    MediaStore.Images.Thumbnails.MINI_KIND);
            imgView.setImageBitmap(thumb);
            tv.setVisibility(View.VISIBLE);
            tv2.setVisibility(View.VISIBLE);

            } else if (resultCode == RESULT_CANCELED) {
            // User cancelled the video capture
            } else {
             //Video capture failed, advise user
            }
        }


    }
    private static Uri getOutputMediaFileUri(int type){
        return Uri.fromFile(getOutputMediaFile(type));
    }

    //create file to store video
    private static File getOutputMediaFile(int type){

        File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
                Environment.DIRECTORY_MOVIES), "MyCameraApp");
        // Create the storage directory if it does not exist
        if (! mediaStorageDir.exists()) {
            if (!mediaStorageDir.mkdirs()) {
                Log.d("MyCameraApp", "failed to create directory");
                return null;
            }
        }

        // Create a media file name
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        File mediaFile;
        if (type == MEDIA_TYPE_VIDEO) {
            mediaFile = new File(mediaStorageDir.getPath() + File.separator +
                    "VID_"+ timeStamp + ".mp4");
        } else {
            return null;
        }

        return mediaFile;
    }

当我在我的模拟器(Genymotion)上启动我的应用程序时,一切都按预期的方式工作,但是当我在真正的Android设备上运行时,应用程序强制关闭用户停止录制的那一分钟。

这是我从Logat获得的输出:

03-17 15:23:06.379  20159-20159/com.example.manolis.mrw E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.example.manolis.mrw, PID: 20159
    java.lang.RuntimeException: Unable to resume activity {com.example.manolis.mrw/com.example.manolis.mrw.Home}: java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=200, result=-1, data=Intent { dat=file:///storage/emulated/0/Movies/MyCameraApp/VID_20150317_152258.mp4 }} to activity {com.example.manolis.mrw/com.example.manolis.mrw.Home}: java.lang.NullPointerException
            at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2880)
            at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2909)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2306)
            at android.app.ActivityThread.access$800(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1246)
            at android.os.Handler.dispatchMessage(Handler.java:106)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5196)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:602)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=200, result=-1, data=Intent { dat=file:///storage/emulated/0/Movies/MyCameraApp/VID_20150317_152258.mp4 }} to activity {com.example.manolis.mrw/com.example.manolis.mrw.Home}: java.lang.NullPointerException
            at android.app.ActivityThread.deliverResults(ActivityThread.java:3499)
            at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2867)
            at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2909)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2306)
            at android.app.ActivityThread.access$800(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1246)
            at android.os.Handler.dispatchMessage(Handler.java:106)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5196)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:602)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.NullPointerException
            at com.example.manolis.mrw.Home.onActivityResult(Home.java:76)
            at android.app.Activity.dispatchActivityResult(Activity.java:5432)
            at android.app.ActivityThread.deliverResults(ActivityThread.java:3495)
            at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2867)
            at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2909)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2306)
            at android.app.ActivityThread.access$800(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1246)
            at android.os.Handler.dispatchMessage(Handler.java:106)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5196)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:602)
            at dalvik.system.NativeStart.main(Native Method)

你知道为什么会这样吗?我错过了什么吗?

1 个答案:

答案 0 :(得分:1)

似乎您的Activity因某种原因被销毁,因此此时fileUri将为null。 我会在onActivityResult

中做过类似的事情
fileUri = getOutputMediaFileUri(MEDIA_TYPE_VIDEO);
String path = fileUri.getPath().toString();

此外,在某些情况下,您将在方法上返回null,因此无论如何都需要进行空检查。