我想为我的android项目使用一个库。 当我使用外部库时，一切正常。 但是当我将.jar添加到我的文件夹＆＃34; libs＆＃34;时，会出现这样的错误：
04-08 10:39:47.879: E/AndroidRuntime(13453): java.lang.RuntimeException: Unable to start activity ComponentInfo{fr.allbrary/eu.janmuller.android.simplecropimage.CropImage}: java.lang.NullPointerException
04-08 10:39:47.879: E/AndroidRuntime(13453): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2245)
04-08 10:39:47.879: E/AndroidRuntime(13453): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2295)
04-08 10:39:47.879: E/AndroidRuntime(13453): at android.app.ActivityThread.access$700(ActivityThread.java:150)
04-08 10:39:47.879: E/AndroidRuntime(13453): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1280)
04-08 10:39:47.879: E/AndroidRuntime(13453): at android.os.Handler.dispatchMessage(Handler.java:99)
04-08 10:39:47.879: E/AndroidRuntime(13453): at android.os.Looper.loop(Looper.java:176)
04-08 10:39:47.879: E/AndroidRuntime(13453): at android.app.ActivityThread.main(ActivityThread.java:5279)
04-08 10:39:47.879: E/AndroidRuntime(13453): at java.lang.reflect.Method.invokeNative(Native Method)
04-08 10:39:47.879: E/AndroidRuntime(13453): at java.lang.reflect.Method.invoke(Method.java:511)
04-08 10:39:47.879: E/AndroidRuntime(13453): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
04-08 10:39:47.879: E/AndroidRuntime(13453): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
04-08 10:39:47.879: E/AndroidRuntime(13453): at dalvik.system.NativeStart.main(Native Method)
04-08 10:39:47.879: E/AndroidRuntime(13453): Caused by: java.lang.NullPointerException
04-08 10:39:47.879: E/AndroidRuntime(13453): at eu.janmuller.android.simplecropimage.CropImage.onCreate(CropImage.java:167)
04-08 10:39:47.879: E/AndroidRuntime(13453): at android.app.Activity.performCreate(Activity.java:5267)
04-08 10:39:47.879: E/AndroidRuntime(13453): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1097)
04-08 10:39:47.879: E/AndroidRuntime(13453): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2209)
04-08 10:39:47.879: E/AndroidRuntime(13453): ... 11 more
代码：
/**
* The activity can crop specific region of interest from an image.
*/
public class CropImage extends MonitoredActivity {
final int IMAGE_MAX_SIZE = 1024;
private static final String TAG = "CropImage";
public static final String IMAGE_PATH = "image-path";
public static final String SCALE = "scale";
public static final String ORIENTATION_IN_DEGREES = "orientation_in_degrees";
public static final String ASPECT_X = "aspectX";
public static final String ASPECT_Y = "aspectY";
public static final String OUTPUT_X = "outputX";
public static final String OUTPUT_Y = "outputY";
public static final String SCALE_UP_IF_NEEDED = "scaleUpIfNeeded";
public static final String CIRCLE_CROP = "circleCrop";
public static final String RETURN_DATA = "return-data";
public static final String RETURN_DATA_AS_BITMAP = "data";
public static final String ACTION_INLINE_DATA = "inline-data";
// These are various options can be specified in the intent.
private Bitmap.CompressFormat mOutputFormat = Bitmap.CompressFormat.JPEG;
private Uri mSaveUri = null;
private boolean mDoFaceDetection = true;
private boolean mCircleCrop = false;
private final Handler mHandler = new Handler();
private int mAspectX;
private int mAspectY;
private int mOutputX;
private int mOutputY;
private boolean mScale;
private CropImageView mImageView;
private ContentResolver mContentResolver;
private Bitmap mBitmap;
private String mImagePath;
boolean mWaitingToPick; // Whether we are wait the user to pick a face.
boolean mSaving; // Whether the "save" button is already clicked.
HighlightView mCrop;
// These options specifiy the output image size and whether we should
// scale the output to fit it (or just crop it).
private boolean mScaleUp = true;
private final BitmapManager.ThreadSet mDecodingThreads =
new BitmapManager.ThreadSet();
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
mContentResolver = getContentResolver();
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.cropimage);
mImageView = (CropImageView) findViewById(R.id.image);
showStorageToast(this);
Intent intent = getIntent();
Bundle extras = intent.getExtras();
if (extras != null) {
if (extras.getString(CIRCLE_CROP) != null) {
if (Build.VERSION.SDK_INT > Build.VERSION_CODES.HONEYCOMB) {
mImageView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
}
mCircleCrop = true;
mAspectX = 1;
mAspectY = 1;
}
mImagePath = extras.getString(IMAGE_PATH);
mSaveUri = getImageUri(mImagePath);
mBitmap = getBitmap(mImagePath);
if (extras.containsKey(ASPECT_X) && extras.get(ASPECT_X) instanceof Integer) {
mAspectX = extras.getInt(ASPECT_X);
} else {
throw new IllegalArgumentException("aspect_x must be integer");
}
if (extras.containsKey(ASPECT_Y) && extras.get(ASPECT_Y) instanceof Integer) {
mAspectY = extras.getInt(ASPECT_Y);
} else {
throw new IllegalArgumentException("aspect_y must be integer");
}
mOutputX = extras.getInt(OUTPUT_X);
mOutputY = extras.getInt(OUTPUT_Y);
mScale = extras.getBoolean(SCALE, true);
mScaleUp = extras.getBoolean(SCALE_UP_IF_NEEDED, true);
}
if (mBitmap == null) {
Log.d(TAG, "finish!!!");
finish();
return;
}
// Make UI fullscreen.
getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
findViewById(R.id.discard).setOnClickListener(
new View.OnClickListener() {
public void onClick(View v) {
setResult(RESULT_CANCELED);
finish();
}
});
findViewById(R.id.save).setOnClickListener(
new View.OnClickListener() {
public void onClick(View v) {
try {
onSaveClicked();
} catch (Exception e) {
finish();
}
}
});
findViewById(R.id.rotateLeft).setOnClickListener(
new View.OnClickListener() {
public void onClick(View v) {
mBitmap = Util.rotateImage(mBitmap, -90);
RotateBitmap rotateBitmap = new RotateBitmap(mBitmap);
mImageView.setImageRotateBitmapResetBase(rotateBitmap, true);
mRunFaceDetection.run();
}
});
findViewById(R.id.rotateRight).setOnClickListener(
new View.OnClickListener() {
public void onClick(View v) {
mBitmap = Util.rotateImage(mBitmap, 90);
RotateBitmap rotateBitmap = new RotateBitmap(mBitmap);
mImageView.setImageRotateBitmapResetBase(rotateBitmap, true);
mRunFaceDetection.run();
}
});
startFaceDetection();
}
private Uri getImageUri(String path) {
return Uri.fromFile(new File(path));
}
private Bitmap getBitmap(String path) {
Uri uri = getImageUri(path);
InputStream in = null;
try {
in = mContentResolver.openInputStream(uri);
//Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeStream(in, null, o);
in.close();
int scale = 1;
if (o.outHeight > IMAGE_MAX_SIZE || o.outWidth > IMAGE_MAX_SIZE) {
scale = (int) Math.pow(2, (int) Math.round(Math.log(IMAGE_MAX_SIZE / (double) Math.max(o.outHeight, o.outWidth)) / Math.log(0.5)));
}
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
in = mContentResolver.openInputStream(uri);
Bitmap b = BitmapFactory.decodeStream(in, null, o2);
in.close();
return b;
} catch (FileNotFoundException e) {
Log.e(TAG, "file " + path + " not found");
} catch (IOException e) {
Log.e(TAG, "file " + path + " not found");
}
return null;
}
private void startFaceDetection() {
if (isFinishing()) {
return;
}
mImageView.setImageBitmapResetBase(mBitmap, true);
Util.startBackgroundJob(this, null,
"Please wait\u2026",
new Runnable() {
public void run() {
final CountDownLatch latch = new CountDownLatch(1);
final Bitmap b = mBitmap;
mHandler.post(new Runnable() {
public void run() {
if (b != mBitmap && b != null) {
mImageView.setImageBitmapResetBase(b, true);
mBitmap.recycle();
mBitmap = b;
}
if (mImageView.getScale() == 1F) {
mImageView.center(true, true);
}
latch.countDown();
}
});
try {
latch.await();
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
mRunFaceDetection.run();
}
}, mHandler);
}
private void onSaveClicked() throws Exception {
// TODO this code needs to change to use the decode/crop/encode single
// step api so that we don't require that the whole (possibly large)
// bitmap doesn't have to be read into memory
if (mSaving) return;
if (mCrop == null) {
return;
}
mSaving = true;
Rect r = mCrop.getCropRect();
int width = r.width();
int height = r.height();
// If we are circle cropping, we want alpha channel, which is the
// third param here.
Bitmap croppedImage;
try {
croppedImage = Bitmap.createBitmap(width, height,
mCircleCrop ? Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565);
} catch (Exception e) {
throw e;
}
if (croppedImage == null) {
return;
}
{
Canvas canvas = new Canvas(croppedImage);
Rect dstRect = new Rect(0, 0, width, height);
canvas.drawBitmap(mBitmap, r, dstRect, null);
}
if (mCircleCrop) {
// OK, so what's all this about?
// Bitmaps are inherently rectangular but we want to return
// something that's basically a circle. So we fill in the
// area around the circle with alpha. Note the all important
// PortDuff.Mode.CLEAR.
Canvas c = new Canvas(croppedImage);
Path p = new Path();
p.addCircle(width / 2F, height / 2F, width / 2F,
Path.Direction.CW);
c.clipPath(p, Region.Op.DIFFERENCE);
c.drawColor(0x00000000, PorterDuff.Mode.CLEAR);
}
/* If the output is required to a specific size then scale or fill */
if (mOutputX != 0 && mOutputY != 0) {
if (mScale) {
/* Scale the image to the required dimensions */
Bitmap old = croppedImage;
croppedImage = Util.transform(new Matrix(),
croppedImage, mOutputX, mOutputY, mScaleUp);
if (old != croppedImage) {
old.recycle();
}
} else {
/* Don't scale the image crop it to the size requested.
* Create an new image with the cropped image in the center and
* the extra space filled.
*/
// Don't scale the image but instead fill it so it's the
// required dimension
Bitmap b = Bitmap.createBitmap(mOutputX, mOutputY,
Bitmap.Config.RGB_565);
Canvas canvas = new Canvas(b);
Rect srcRect = mCrop.getCropRect();
Rect dstRect = new Rect(0, 0, mOutputX, mOutputY);
int dx = (srcRect.width() - dstRect.width()) / 2;
int dy = (srcRect.height() - dstRect.height()) / 2;
/* If the srcRect is too big, use the center part of it. */
srcRect.inset(Math.max(0, dx), Math.max(0, dy));
/* If the dstRect is too big, use the center part of it. */
dstRect.inset(Math.max(0, -dx), Math.max(0, -dy));
/* Draw the cropped bitmap in the center */
canvas.drawBitmap(mBitmap, srcRect, dstRect, null);
/* Set the cropped bitmap as the new bitmap */
croppedImage.recycle();
croppedImage = b;
}
}
// Return the cropped image directly or save it to the specified URI.
Bundle myExtras = getIntent().getExtras();
if (myExtras != null && (myExtras.getParcelable("data") != null
|| myExtras.getBoolean(RETURN_DATA))) {
Bundle extras = new Bundle();
extras.putParcelable(RETURN_DATA_AS_BITMAP, croppedImage);
setResult(RESULT_OK,
(new Intent()).setAction(ACTION_INLINE_DATA).putExtras(extras));
finish();
} else {
final Bitmap b = croppedImage;
Util.startBackgroundJob(this, null, getString(R.string.saving_image),
new Runnable() {
public void run() {
saveOutput(b);
}
}, mHandler);
}
}
private void saveOutput(Bitmap croppedImage) {
if (mSaveUri != null) {
OutputStream outputStream = null;
try {
outputStream = mContentResolver.openOutputStream(mSaveUri);
if (outputStream != null) {
croppedImage.compress(mOutputFormat, 90, outputStream);
}
} catch (IOException ex) {
Log.e(TAG, "Cannot open file: " + mSaveUri, ex);
setResult(RESULT_CANCELED);
finish();
return;
} finally {
Util.closeSilently(outputStream);
}
Bundle extras = new Bundle();
Intent intent = new Intent(mSaveUri.toString());
intent.putExtras(extras);
intent.putExtra(IMAGE_PATH, mImagePath);
intent.putExtra(ORIENTATION_IN_DEGREES, Util.getOrientationInDegree(this));
setResult(RESULT_OK, intent);
} else {
Log.e(TAG, "not defined image url");
}
croppedImage.recycle();
finish();
}
@Override
protected void onPause() {
super.onPause();
BitmapManager.instance().cancelThreadDecoding(mDecodingThreads);
}
@Override
protected void onDestroy() {
super.onDestroy();
if (mBitmap != null) {
mBitmap.recycle();
}
}
Runnable mRunFaceDetection = new Runnable() {
@SuppressWarnings("hiding")
float mScale = 1F;
Matrix mImageMatrix;
FaceDetector.Face[] mFaces = new FaceDetector.Face[3];
int mNumFaces;
// For each face, we create a HightlightView for it.
private void handleFace(FaceDetector.Face f) {
PointF midPoint = new PointF();
int r = ((int) (f.eyesDistance() * mScale)) * 2;
f.getMidPoint(midPoint);
midPoint.x *= mScale;
midPoint.y *= mScale;
int midX = (int) midPoint.x;
int midY = (int) midPoint.y;
HighlightView hv = new HighlightView(mImageView);
int width = mBitmap.getWidth();
int height = mBitmap.getHeight();
Rect imageRect = new Rect(0, 0, width, height);
RectF faceRect = new RectF(midX, midY, midX, midY);
faceRect.inset(-r, -r);
if (faceRect.left < 0) {
faceRect.inset(-faceRect.left, -faceRect.left);
}
if (faceRect.top < 0) {
faceRect.inset(-faceRect.top, -faceRect.top);
}
if (faceRect.right > imageRect.right) {
faceRect.inset(faceRect.right - imageRect.right,
faceRect.right - imageRect.right);
}
if (faceRect.bottom > imageRect.bottom) {
faceRect.inset(faceRect.bottom - imageRect.bottom,
faceRect.bottom - imageRect.bottom);
}
hv.setup(mImageMatrix, imageRect, faceRect, mCircleCrop,
mAspectX != 0 && mAspectY != 0);
mImageView.add(hv);
}
// Create a default HightlightView if we found no face in the picture.
private void makeDefault() {
HighlightView hv = new HighlightView(mImageView);
int width = mBitmap.getWidth();
int height = mBitmap.getHeight();
Rect imageRect = new Rect(0, 0, width, height);
// make the default size about 4/5 of the width or height
int cropWidth = Math.min(width, height) * 4 / 5;
int cropHeight = cropWidth;
if (mAspectX != 0 && mAspectY != 0) {
if (mAspectX > mAspectY) {
cropHeight = cropWidth * mAspectY / mAspectX;
} else {
cropWidth = cropHeight * mAspectX / mAspectY;
}
}
int x = (width - cropWidth) / 2;
int y = (height - cropHeight) / 2;
RectF cropRect = new RectF(x, y, x + cropWidth, y + cropHeight);
hv.setup(mImageMatrix, imageRect, cropRect, mCircleCrop,
mAspectX != 0 && mAspectY != 0);
mImageView.mHighlightViews.clear(); // Thong added for rotate
mImageView.add(hv);
}
// Scale the image down for faster face detection.
private Bitmap prepareBitmap() {
if (mBitmap == null) {
return null;
}
// 256 pixels wide is enough.
if (mBitmap.getWidth() > 256) {
mScale = 256.0F / mBitmap.getWidth();
}
Matrix matrix = new Matrix();
matrix.setScale(mScale, mScale);
return Bitmap.createBitmap(mBitmap, 0, 0, mBitmap.getWidth(), mBitmap.getHeight(), matrix, true);
}
public void run() {
mImageMatrix = mImageView.getImageMatrix();
Bitmap faceBitmap = prepareBitmap();
mScale = 1.0F / mScale;
if (faceBitmap != null && mDoFaceDetection) {
FaceDetector detector = new FaceDetector(faceBitmap.getWidth(),
faceBitmap.getHeight(), mFaces.length);
mNumFaces = detector.findFaces(faceBitmap, mFaces);
}
if (faceBitmap != null && faceBitmap != mBitmap) {
faceBitmap.recycle();
}
mHandler.post(new Runnable() {
public void run() {
mWaitingToPick = mNumFaces > 1;
if (mNumFaces > 0) {
for (int i = 0; i < mNumFaces; i++) {
handleFace(mFaces[i]);
}
} else {
makeDefault();
}
mImageView.invalidate();
if (mImageView.mHighlightViews.size() == 1) {
mCrop = mImageView.mHighlightViews.get(0);
mCrop.setFocus(true);
}
if (mNumFaces > 1) {
Toast.makeText(CropImage.this,
"Multi face crop help",
Toast.LENGTH_SHORT).show();
}
}
});
}
};
public static final int NO_STORAGE_ERROR = -1;
public static final int CANNOT_STAT_ERROR = -2;
public static void showStorageToast(Activity activity) {
showStorageToast(activity, calculatePicturesRemaining(activity));
}
public static void showStorageToast(Activity activity, int remaining) {
String noStorageText = null;
if (remaining == NO_STORAGE_ERROR) {
String state = Environment.getExternalStorageState();
if (state.equals(Environment.MEDIA_CHECKING)) {
noStorageText = activity.getString(R.string.preparing_card);
} else {
noStorageText = activity.getString(R.string.no_storage_card);
}
} else if (remaining < 1) {
noStorageText = activity.getString(R.string.not_enough_space);
}
if (noStorageText != null) {
Toast.makeText(activity, noStorageText, 5000).show();
}
}
public static int calculatePicturesRemaining(Activity activity) {
try {
/*if (!ImageManager.hasStorage()) {
return NO_STORAGE_ERROR;
} else {*/
String storageDirectory = "";
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
storageDirectory = Environment.getExternalStorageDirectory().toString();
}
else {
storageDirectory = activity.getFilesDir().toString();
}
StatFs stat = new StatFs(storageDirectory);
float remaining = ((float) stat.getAvailableBlocks()
* (float) stat.getBlockSize()) / 400000F;
return (int) remaining;
//}
} catch (Exception ex) {
// if we can't stat the filesystem then we don't know how many
// pictures are remaining. it might be zero but just leave it
// blank since we really don't know.
return CANNOT_STAT_ERROR;
}
}
}
为什么？
答案 0 :(得分：1)
使用以下程序添加jar文件： -
右键单击项目---＆gt;构建路径---＆gt;配置构建路径...--->在左侧，您必须选择Java Build Path ---＆gt; Libraries --- ＆gt;添加外部JAR ---＆gt; ok ---＆gt; ok
希望这能解决问题
答案 1 :(得分：0)
这是构建路径问题。
确保您的bin文件夹未包含在构建路径中。
右键点击您的项目＆gt;去物业＆gt;构建路径。
确保Honeycomb库位于您的libs /文件夹中，而不是源文件夹中。
在构建路径中将libs /库中的库包含在内。
顺便说一下，您可能需要引入android-support-v4库以获得Ice Cream Sandwich支持而不是Honeycomb支持库答案 2 :(得分：-1)
你不能简单地在你的应用程序中添加jar文件..转到buildpath然后将外部jar添加到你的应用程序然后它将工作