Develop Reference

Android studio when try to build apk Error: "Expecting a file or a directory"

So i get this Error when i try to build an Apk in Android Studio: "Expecting a file or a directory: D:\Android\game - Android Studio\core\Users\ManuGil\Documents\LibGDX\Juegos 15-20\360\game\libs\tween-engine-api.jar". So and when it has showed me expecting a file ore Directory i thought i am going to look for this file but in my explorer i just can find the files until "core" cause in the Folder core there's no folder "Users".
The picture shows the error in Android Studio

Please click File-->Project Structrue ... --> SDK Location -->JDK location
Then, type this in the box !!
C:\Program Files\Java\jdk1.8.0_152
'jdk1.8.0_152' could be different depending on the version of jdk.
i hope this works for someone who suffers from the error

Problems with facebook-android-sdk

I am following this tutorial: https://developers.facebook.com/docs/android/getting-started but after importing the samples I get many errors. I had to install other version of eclipse and two different version of the facebook-android-sdk since version 3.15.0 did not have the bin folder to install the Facebook app on the emulator. The errors I get are the following: (note that adt-bundle-windows-x86-20131030\sdk\ was the eclipse previous version, I had to install a new one since the old one was not working properly anymore).
Description Resource Path Location Type
The project cannot be built until build path errors are resolved SwitchUserSample Unknown Java Problem
The project cannot be built until build path errors are resolved GraphApiSample Unknown Java Problem
The container 'Android Dependencies' references non existing library 'C:\Users\USER\Desarrollo\adt-bundle-windows-x86-20131030\sdk\tools\support\annotations.jar' FacebookSDK Build path Build Path Problem
The container 'Android Dependencies' references non existing library 'C:\Users\USER\Dropbox\PruebaTandem\facebook-android-sdk- 3.14.1\facebook\bin\facebooksdk.jar' HelloFacebookSample Build path Build Path Problem
The project cannot be built until build path errors are resolved RPSSample Unknown Java Problem
The project cannot be built until build path errors are resolved Scrumptious Unknown Java Problem
The container 'Android Dependencies' references non existing library 'C:\Users\USER\Dropbox\PruebaTandem\facebook-android-sdk-3.14.1\facebook\bin\facebooksdk.jar' GraphApiSample Build path Build Path Problem
The container 'Android Dependencies' references non existing library 'C:\Users\USER\Dropbox\PruebaTandem\facebook-android-sdk-3.14.1\facebook\bin\facebooksdk.jar' Scrumptious Build path Build Path Problem
The project cannot be built until build path errors are resolved ProfilePictureSample Unknown Java Problem
The container 'Android Dependencies' references non existing library 'C:\Users\USER\Dropbox\PruebaTandem\facebook-android-sdk-3.14.1\facebook\bin\facebooksdk.jar' RPSSample Build path Build Path Problem
The project cannot be built until build path errors are resolved SessionLoginSample Unknown Java Problem
The project cannot be built until build path errors are resolved PlacePickerSample Unknown Java Problem
The project cannot be built until build path errors are resolved NativeAdSample Unknown Java Problem
The container 'Android Dependencies' references non existing library 'C:\Users\USER\Dropbox\PruebaTandem\facebook-android-sdk-3.14.1\facebook\bin\facebooksdk.jar' PlacePickerSample Build path Build Path Problem
The container 'Android Dependencies' references non existing library 'C:\Users\USER\Dropbox\PruebaTandem\facebook-android-sdk-3.14.1\facebook\bin\facebooksdk.jar' ProfilePictureSample Build path Build Path Problem
The project cannot be built until build path errors are resolved AdUnitsSample Unknown Java Problem
The project cannot be built until build path errors are resolved HelloFacebookSample Unknown Java Problem
The container 'Android Dependencies' references non existing library 'C:\Users\USER\Desarrollo\adt-bundle-windows-x86-20131030\sdk\tools\support\annotations.jar' NativeAdSample Build path Build Path Problem
The container 'Android Dependencies' references non existing library 'C:\Users\USER\Dropbox\PruebaTandem\facebook-android-sdk-3.14.1\facebook\bin\facebooksdk.jar' FriendPickerSample Build path Build Path Problem
The container 'Android Dependencies' references non existing library 'C:\Users\USER\Desarrollo\adt-bundle-windows-x86-20131030\sdk\tools\support\annotations.jar' AdUnitsSample Build path Build Path Problem
The container 'Android Dependencies' references non existing library 'C:\Users\USER\Dropbox\PruebaTandem\facebook-android-sdk-3.14.1\facebook\bin\facebooksdk.jar' SessionLoginSample Build path Build Path Problem
The container 'Android Dependencies' references non existing library 'C:\Users\USER\Dropbox\PruebaTandem\facebook-android-sdk-3.14.1\facebook\bin\facebooksdk.jar' SwitchUserSample Build path Build Path Problem
The project cannot be built until build path errors are resolved FacebookSDK Unknown Java Problem
The project cannot be built until build path errors are resolved FriendPickerSample Unknown Java Problem
Thanks!

I also had this problem and solved it as follows:
Go to android-sdk\extras\android\support\annotations and copy android-support-annotations.jar and paste it in android-sdk\tools\support.
Rename to annotations
Just close all sample projects that is referencing FacebookSDK, clean and build FacebookSDK, facebooksdk.jar will be created.

Issues in Manual OpenCV4Android SDK setup

After the import step on this page: http://docs.opencv.org/doc/tutorials/introduction/android_binary_package/O4A_SDK.html#import-opencv-library-and-samples-to-the-eclipse
I keep getting the following errors like in a popup in Eclipse:
Building workspace: Errors occurred during the build. Errors running
builder 'Android Resource Manager' on project 'OpenCV Library -
#OPENCV_VERSION#'. java.lang.NullPointerException Errors running
builder 'Android Resource Manager' on project 'OpenCV Sample - 15
puzzle'. java.lang.NullPointerException Errors running builder
'Android Resource Manager' on project 'OpenCV Sample -
camera-calibration'. java.lang.NullPointerException
Cleaning all projects: Errors occurred during the build. Errors
running builder 'Android Package Builder' on project 'OpenCV Library -
#OPENCV_VERSION#'. Resource '/OpenCV Library - #OPENCV_VERSION#/bin'
does not exist. Resource '/OpenCV Library - #OPENCV_VERSION#/bin' does
not exist. I followed the warning and note given at the bottom as
well, but that did help.
My OpenCV4Android SDK version is 2.4.9.

I ran into the same problem -- I didn't wind up needing to switch to OpenCV4Android 2.4.8, but deleting my 2.4.9 directory and re-unzipping it and going through the steps from scratch seemed to fix everything. I'm sure I just corrupted some files, and re-extracting my SDK fixed it.
So long story short:
Make sure you follow EVERY step in the tutorial:
http://docs.opencv.org/doc/tutorials/introduction/android_binary_package/O4A_SDK.html
Make SURE that when you import the sample projects that you do it from the ROOT of the SDK directory -- not from the sample directory -- otherwise you miss the library.
Make SURE that you don't extract your OpenCV directory into a directory with spaces in the path (such as "My Documents").
And if you're wrestling it with a while and you can't seem to get it working, then don't hesitate to quit eclipse, delete your workspace, delete your OpenCV directory, and re-extract from the downloaded zip file and try again.

I had the same frustrating problem, I had to do two steps (different again!):
Open Properties for the Open CV library project (mine was OpenCV Library - 2.4.10), go to Android -> Project Build Target, and select a target name. (This is mentioned in the tutorial.)
Still in the Properties dialog, go to Java Build Path -> Source, at the bottom where it says Default output folder: mine said "OpenCV Library - 2.4.10/cls" - I changed this to "OpenCV Library - 2.4.10/bin"
And now it's building without errors.

I did both of the following together:
Set NDKROOT for all projects individually even though the environment variable existed in my bashrc.
Switched to OpenCV4Android SDK version 2.4.8

Build errors while trying to set up OpenCV4Android

I am trying to run an OpenCV4Android in my eclipse. I am working on Linux(CentOS 6).
I have done everything mentioned in this link but I am still getting build errors. I have also set the NDK path in preferences hat is not mentioned in the tutorial and tried a lot more things. When I try to build the library project the console gives:
"Cannot run program "/ndk-build": Unknown reason
Error: Program "/ndk-build" is not found in PATH"
All the projects also have build errors and the src and gen folders in openCV4 Library is not created and the build path shows:
"Unable to get system library for the project"
When i try to change the project properties I get an error saying the page contains invalid values and I cannot change the android api version. Plz help. Have been trying to set this up since 3 days now.
Thank you.

First Clean and Build you library Project alone and then try cleaning all your projects. In order to solve the "Cannot run program "/ndk-build": Unknown reason Error: Program "/ndk-build" is not found in PATH" error, Try the following steps:
Head to the project's properties. If you're using Windows, the shortcut is Alt + Enter; or simply right-click the project name to find its properties.
Go to the C/C++ Build section; under Builder Settings tab in Build command: text box you're likely to find something similar to that below, if it's empty then type in the similar text - namely: ${NDKROOT}/ndk-build.cmd where NDKROOT, as its name implies, refers to the path where your NDK root folder exists.
Now you must inform eclipse what NDKROOT equates to; as in, where is the NDK root path. You can do this by heading to (in your project's properties) C/C++ Build > Environment > press Add…
Now add your environment variable named NDKROOT (the Name) with the relevant path (Value). Note that you're to repeat this per NDK project. You would get a window similar to that below.
Press OK to the New variable input window and then OK again to the properties window.
Hopefully this will help!

Eclipse LogCat unreadable - OpenCV / Android NDK

I'm pretty new to Eclipse and Android dev and only recently installed NDK and OpenCV and ever since I've been battling. Win8/Eclipse Juno/NDK R8D/OpenCV 2.4.4
Project folder has this red exclamation mark but no files within are showing any errors.
CDT builds the app just fine!
Here's what LogCat gives me:
Any clue? Cheers
EDIT:
after I followed your advise I ended up with the following:
Description Resource Path Location Type
Project 'OpenCV Library - 2.4.4' is missing required library: 'C:\Program Files (x86)\Android\android-sdk\platforms\android-17\android.jar' OpenCV Library - 2.4.4 Build path Build Path Problem
The container 'Android Dependencies' references non existing library 'C:\Android\android-opencv-2-4-4\sdk\java\bin\opencv library - 2.4.4.jar' Test1 Build path Build Path Problem

If the project folder is showing a red exclamation mark, try going to window > show view > problems and there may be a better description there of any problems.
The log above looks like a general log from your device. If you want to log from a specific running application, run the app on a device from eclipse and type app:com.yourpackagename in the text field above the LogCat output.