我在片段中使用此方法压缩图片，如果我没有弄错，然后将其上传到google firebase服务器：
Bitmap thumb_bitmap = new Compressor(this.getActivity())
.setMaxWidth(200)
.setMaxHeight(200)
.setQuality(75)
.compressToBitmap(thumb_filePath);
我最终从Android Studio收到以下错误：
java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.graphics.Bitmap.compress(android.graphics.Bitmap$CompressFormat, int, java.io.OutputStream)' on a null object reference
这是该方法的其余代码：
private void uploadImage() {
if (filePath[0] != null && filePath[1] != null) {
final ProgressDialog progressDialog = new ProgressDialog(getActivity());
//progressDialog.setTitle("Uploading...");
//progressDialog.show();
for ( Uri path : filePath ) {
id_or_proof += 1;
File thumb_filePath = new File(path.getPath());
Log.d ( "THUMB FILE PATH", path.getPath() );
String current_user_id = mCurrentUser.getUid();
Bitmap thumb_bitmap = new Compressor(this.getActivity())
.setMaxWidth(200)
.setMaxHeight(200)
.setQuality(75)
.compressToBitmap(thumb_filePath);
Log.d ( "BITMAP", String.valueOf(thumb_bitmap));
ByteArrayOutputStream baos = new ByteArrayOutputStream();
thumb_bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
final byte[] thumb_byte = baos.toByteArray();
StorageReference filepath = mImageStorage.child("profile_images").child(current_user_id + ".jpg");
final StorageReference thumb_filepath = mImageStorage.child("profile_images").child("thumbs").child(current_user_id + ".jpg");
filepath.putFile(path).addOnCompleteListener(new OnCompleteListener<UploadTask.TaskSnapshot>() {
@Override
public void onComplete(@NonNull Task<UploadTask.TaskSnapshot> task) {
if(task.isSuccessful()){
final String download_url = task.getResult().getDownloadUrl().toString();
UploadTask uploadTask = thumb_filepath.putBytes(thumb_byte);
uploadTask.addOnCompleteListener(new OnCompleteListener<UploadTask.TaskSnapshot>() {
@Override
public void onComplete(@NonNull Task<UploadTask.TaskSnapshot> thumb_task) {
String thumb_downloadUrl = thumb_task.getResult().getDownloadUrl().toString();
if(thumb_task.isSuccessful()){
if ( id_or_proof == 1 ) {
Map update_hashMap = new HashMap();
update_hashMap.put("id_image", download_url);
update_hashMap.put("thumb_id_image", thumb_downloadUrl);
mUserDatabase.updateChildren(update_hashMap).addOnCompleteListener(new OnCompleteListener<Void>() {
@Override
public void onComplete(@NonNull Task<Void> task) {
if (task.isSuccessful()) {
mProgressDialog.dismiss();
Toast.makeText(getActivity(), "Success Uploading.", Toast.LENGTH_LONG).show();
}
}
});
}
if ( id_or_proof == 2 ) {
Map update_hashMap = new HashMap();
update_hashMap.put("proof_image", download_url);
update_hashMap.put("thumb_proof_image", thumb_downloadUrl);
mUserDatabase.updateChildren(update_hashMap).addOnCompleteListener(new OnCompleteListener<Void>() {
@Override
public void onComplete(@NonNull Task<Void> task) {
if (task.isSuccessful()) {
mProgressDialog.dismiss();
Toast.makeText(getActivity(), "Success Uploading.", Toast.LENGTH_LONG).show();
}
}
});
}
} else {
Toast.makeText(getActivity(), "Error in uploading thumbnail.", Toast.LENGTH_LONG).show();
mProgressDialog.dismiss();
}
}
});
} else {
Toast.makeText(getActivity(), "Error in uploading.", Toast.LENGTH_LONG).show();
mProgressDialog.dismiss();
}
}
});
}// end of for
}// end of if ()
} // end of uploadImage()
我需要帮助才能弄清楚为什么我会收到错误，以及我如何解决错误。
非常赞赏。
这里是logcat：
03-14 15:36:57.383 2780-2780/in.tvac.akshaye.lapitchat E/BitmapFactory: Unable to decode stream: java.io.FileNotFoundException: /document/60 (No such file or directory)
03-14 15:36:57.383 2780-2780/in.tvac.akshaye.lapitchat E/BitmapFactory: Unable to decode stream: java.io.FileNotFoundException: /document/60 (No such file or directory)
03-14 15:36:57.383 2780-2780/in.tvac.akshaye.lapitchat D/BITMAP: null
03-14 15:36:57.383 2780-2780/in.tvac.akshaye.lapitchat D/AndroidRuntime: Shutting down VM
03-14 15:36:57.384 2780-2780/in.tvac.akshaye.lapitchat E/AndroidRuntime: FATAL EXCEPTION: main
Process: in.tvac.akshaye.lapitchat, PID: 2780
java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.graphics.Bitmap.compress(android.graphics.Bitmap$CompressFormat, int, java.io.OutputStream)' on a null object reference
at in.tvac.akshaye.lapitchat.PersonalInforamtionFragment.uploadImage(PersonalInforamtionFragment.java:649)
at in.tvac.akshaye.lapitchat.PersonalInforamtionFragment.access$1900(PersonalInforamtionFragment.java:57)
at in.tvac.akshaye.lapitchat.PersonalInforamtionFragment$8.onComplete(PersonalInforamtionFragment.java:767)
at com.google.android.gms.tasks.zzc$1.run(Unknown Source:23)
at android.os.Handler.handleCallback(Handler.java:790)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6494)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
答案 0 :(得分：2)
您似乎将错误的Uri传递给新文件，因此找不到您的文件。
从外部存储中获取。
如果您尝试从外部存储中获取文件，则必须添加此权限：
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
然后创建如下路径：
String filePath = Environment.getExternalStorageDirectory() + "/document/60";
Uri path = Uri.parse(filePath);
从应用存储中获取
如果您尝试从App Storage获取文件，只需像这样构建您的Uri：
String filePath = getActivity().getFilesDir() + "/document/60";
Uri path = Uri.parse(filePath);
答案 1 :(得分：0)
使用正确的上下文
Bitmap thumb_bitmap = new Compressor(this.getActivity())
.setMaxWidth(200)
.setMaxHeight(200)
.setQuality(75)
.compressToBitmap(thumb_filePath);
将其替换为
Bitmap thumb_bitmap = new Compressor(getActivity())
.setMaxWidth(200)
.setMaxHeight(200)
.setQuality(75)
.compressToBitmap(thumb_filePath);
路径也应该正确