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Bitmapfun sample example gives a NullPointerException

Example source: http://developer.android.com/training/displaying-bitmaps/index.html

I don’t know why I can’t start the project at all.

Log code

09-06 13:14:13.664: E/AndroidRuntime(591): FATAL EXCEPTION: main
09-06 13:14:13.664: E/AndroidRuntime(591): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.android.bitmapfun/com.example.android.bitmapfun.ui.ImageGridActivity}: java.lang.NullPointerException
09-06 13:14:13.664: E/AndroidRuntime(591):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1955)
09-06 13:14:13.664: E/AndroidRuntime(591):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1980)
09-06 13:14:13.664: E/AndroidRuntime(591):  at android.app.ActivityThread.access$600(ActivityThread.java:122)
09-06 13:14:13.664: E/AndroidRuntime(591):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1146)
09-06 13:14:13.664: E/AndroidRuntime(591):  at android.os.Handler.dispatchMessage(Handler.java:99)
09-06 13:14:13.664: E/AndroidRuntime(591):  at android.os.Looper.loop(Looper.java:137)
09-06 13:14:13.664: E/AndroidRuntime(591):  at android.app.ActivityThread.main(ActivityThread.java:4340)
09-06 13:14:13.664: E/AndroidRuntime(591):  at java.lang.reflect.Method.invokeNative(Native Method)
09-06 13:14:13.664: E/AndroidRuntime(591):  at java.lang.reflect.Method.invoke(Method.java:511)
09-06 13:14:13.664: E/AndroidRuntime(591):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
09-06 13:14:13.664: E/AndroidRuntime(591):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
09-06 13:14:13.664: E/AndroidRuntime(591):  at dalvik.system.NativeStart.main(Native Method)
09-06 13:14:13.664: E/AndroidRuntime(591): Caused by: java.lang.NullPointerException
09-06 13:14:13.664: E/AndroidRuntime(591):  at com.example.android.bitmapfun.util.DiskLruCache.getDiskCacheDir(DiskLruCache.java:268)
09-06 13:14:13.664: E/AndroidRuntime(591):  at com.example.android.bitmapfun.util.ImageCache.init(ImageCache.java:121)
09-06 13:14:13.664: E/AndroidRuntime(591):  at com.example.android.bitmapfun.util.ImageCache.<init>(ImageCache.java:61)
09-06 13:14:13.664: E/AndroidRuntime(591):  at com.example.android.bitmapfun.util.ImageCache.findOrCreateCache(ImageCache.java:107)
09-06 13:14:13.664: E/AndroidRuntime(591):  at com.example.android.bitmapfun.ui.ImageGridFragment.onCreate(ImageGridFragment.java:96)
09-06 13:14:13.664: E/AndroidRuntime(591):  at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:834)
09-06 13:14:13.664: E/AndroidRuntime(591):  at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1080)
09-06 13:14:13.664: E/AndroidRuntime(591):  at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:622)
09-06 13:14:13.664: E/AndroidRuntime(591):  at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1416)
09-06 13:14:13.664: E/AndroidRuntime(591):  at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:505)
09-06 13:14:13.664: E/AndroidRuntime(591):  at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1133)
09-06 13:14:13.664: E/AndroidRuntime(591):  at android.app.Activity.performStart(Activity.java:4475)
09-06 13:14:13.664: E/AndroidRuntime(591):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1928)
09-06 13:14:13.664: E/AndroidRuntime(591):  ... 11 more
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2 answers

Have you tried running this in an emulator?

My problem was that I had an AVD configuration with Galaxy Nexus and Nexus S, but no SD storage was installed for them. You see that these devices do not have SD cards that you can remove, they only have internal memory, but this memory is divided into an “internal” section for applications and an “external” section that you can install on your computer.

Bitmapfun ImageCahcer Environment.isExternalStorageRemovable(), false , , SD-.

, SD- , .

+1

, null . :

public static String hashKeyForDisk(String key) {
    String cacheKey;
    try {
        final MessageDigest mDigest = MessageDigest.getInstance("MD5");
        if (key == null) {
            Log.e("TEST","key = null");
            throw new IllegalArgumentException(" key == null");
        }

        if (mDigest == null) {
            Log.e("TEST","mDigest = null");

            return String.valueOf(key.hashCode());
        }
        byte[] bytes = key.getBytes();
        mDigest.update(bytes);
        cacheKey = bytesToHexString(mDigest.digest());
    } catch (NoSuchAlgorithmException e) {
        cacheKey = String.valueOf(key.hashCode());
    }
    return cacheKey;
}
+1

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