I am having a lot of trouble adding the WEKA library to a project I am working on. I have followed several tutorials that explain how to do this including the Android Developers guide:
http://developer.android.com/guide/appendix/faq/commontasks.html#addexternallibrary
and several of the postings on SO.
I have created a folder in my project with the weka.jar file, created a new library (adding the weka.jar file to the library) and included this library in my build path. I have also added the library under the "Order and Export" tab in the project properties.
I have also tried importing the jar file so that the actual contents of the jar are extracted into a directory in my project.
The end result of all of this is that my project is able to build correctly and without error, but when it comes time to run my code on the emulator I get the following exception:
04-10 22:52:21.051: ERROR/dalvikvm(582): Could not find class 'weka.classifiers.trees.J48', referenced from method edu.usc.student.composure.classifier.GaitClassifierImpl.
with J48 being the class I reference in my code.
Does anyone have any additional suggestions that I may have overlooked?
Thanks!
I just finished my first revision of https://github.com/rjmarsan/Weka-for-Android
Hope it helps!
WEKA is not going to work on Android without changes. J48, for example, requires the java.lang.Cloneable interface, which is not available in Android.
What you need to do is check out the WEKA source code from Subversion, add it to your project (removing the JAR file), compile it, and fix all the compile errors. There may be quite a few of these.
Related
I just add external jar(android support.v4.jar) to my project using eclipse IDE.
But it show empty packages.Can anyone guide me how to solve this.?
External jar show empty packages:
I just add external jar(android support.v4.jar) to my project using eclipse IDE.
Not quite. You added support-v4-23.1.1-sources.jar. The key part of that filename, with respect to your problem, is sources. This JAR contains Java source code, not compiled Java classes.
Can anyone guide me how to solve this.?
Google is no longer supporting Eclipse. There is no official distribution of any of the support libraries as simple JARs, or even Eclipse-style library projects.
The simple solution is to move to Android Studio, or possibly IntelliJ IDEA, instead of using Eclipse.
I'm using the commonsguy cwac-camera library, as per the demo-layout example, documented in "Working directlly with cameraview".
All is fine referencing camera/ and camera-v9/ as Android library projects in source form (I need Android 2.3 compatibility, that's what camera-v9 is for).
When I switch to using the library via JARs:
- cwac-camera-v9-0.6.8.jar only includes CameraFragment and BuildConfig classes, so I need also cwac-camera-0.6.8.jar with the other classes.
- including both JARs causes the following self-explaining error when running the project (not at compile time) Conversion to Dalvik format failed: Unable to execute dex: Multiple dex files define Lcom/commonsware/cwac/camera/BuildConfig;
I could just use the source as library project, or use Gradle, but I want to know if this is a bug to open an issue on Github, or if I'm doing something wrong.
To replicate the error, just clone the demo-layout example add both .jar files to libs folder, and run the project.
No, this appears to be my fault. They must have changed something in the Gradle build process that I am using to create the JARs. I will try to fix this tomorrow. In the meantime, you could go into the cwac-camera-v9 JAR and try removing the classes in com.commonsware.cwac.camera, leaving only those classes incom.commonsware.cwac.camera.acl.
My apologies for this, and thanks for pointing it out!
I am going to use SkyEpub 3 library in my android application to read ebooks in epub format. To get familiar with the method of using SkyEpub I have downloaded its android demo project from here.
Its demo project is working properly, But when I use the skyepub.jar in my own project, it says some methods and classes from the jar file are undefined. Of course in the mean time I am using an unlicensed version of this library. I want to test it before buying the license if it was ok. I doubt that the errors are because of using the unlicensed version of the library in my project.
Can any one tell me please what is the problem exactly?
Thank you in advance.
Because there are a lot of classes ,which are not in jar, in example project. In the example, they create a lot of classes by extends another classes from jar. I used this jar before.
I found what was the problem. I increased priority of the jar file in eclipse. Now it works.
I have seen this question, and have some more doubts regarding creating a jar file which I can distribute and can be used in any android applications.
What my requirement is
As I said, I want to build and distribute a closed source library. I
don't want the source code to be visible.
In that library I don't want to use any assets, layouts, resources
etc. But I want to use some android specific codes, like getting
android device id.
The most popular answer in the above linked SO question tells to create a regular java project and import android.jar in it. I tried to do that, but I don't know how to add android.jar to any java project. I would like to get some clarification on that too.
Moreover I would like to know if there are any other methods using android sdk itself (without using java project) create a closed source library jar file.
I think what I want is possible, since google analytics for android native apps seems to have done it. I am sure in the .jar file they distribute they are using android specific codes, since there seems no other way for them to get the device information to display in the analytics viewer.
EDIT : CAN SOMEONE CLARIFY THIS??
I think I have made some progress. This is what I have done
Created a regular android project (not library project, the "is
Library" checkmark is unchecked)
In the project I have coded out my logic. It uses some android
specific classes like SharedPreference, UUID, PackageManager. But
nothing related with assets, layouts also no class extending
Activity. Just a java class extending java.lang.object
Exported the project using Project->rightclick->export->Java->JAR
file. In the next screen I unchecked the checkbox near
AndroidManifest.xml. Set a destination directory to export and
clicked next thrice with keeping the default settings. Then I clicked
Finish, and got a lovely libMyLibraryName.jar at my desktop.
Then I created another android project, added this libMyLibraryName.jar to new project using project->rightclick->properties->java build path -> libraries->add external jar.
And I tried to use my class in the library, in my new project
MyLibraryClass objClass = new MyLibraryClass(this);
And I was able to compile and run successfully. I even sent the library to one of my co worker who was able to use the library in his on machine (Just making sure library project in my workspace wont influence the project using it).
Now I have 2 questions.
1) My first question is , what they meant by the term "true library" in the below given documentation ? Is it any non android java project which can be exported to a JAR file?
However, a library project differs from an standard Android
application project in that you cannot compile it directly to its own
.apk and run it on an Android device. Similarly, you cannot export
the library project to a self-contained JAR file, as you would do
for a true library. Instead, you must compile the library indirectly,
by referencing the library in the dependent application and building
that application.
Well this portion is taken from documentation under title "Library Projects".
2) My second question is, anything wrong with the way I have created the JAR file? Any possible pitfalls which might bite me back later? I would like to make sure I am not doing something terribly wrong, before using it in my important projects.
I might add that I didn't try the method of creating a JAVA project and importing android.jar. I am ready to try that one, if what I have done currently is wrong.
The android.jar will be located where you installed your Android SDK. Under the platforms directory there should be a number of other directories named android-<version>. The android.jar will be there. Choose the one specific to the minimum android version you are targeting.
Once you have that, copy it into your project. If you're using eclipse I think you can just cut and paste jars straight into your project, right click and add it to build path. If you're not using eclipse or any other IDE, you just need to ensure that the android.jar is on the classpath when building your jar file.
After that your newly built android library can be dropped into any Android project.
In answer to your additional questions:
What they mean by a true library is a jar file as opposed to an Android library project.
I don't think there's anything wrong with the way you created the jar file. I would have made it using the android.jar as I mentioned above but your way should also work. To verify this I would examine the jar contents and make sure all you have in there is .class files.
I'm trying to use an ActionBar library project in my app but I keep getting errors when trying to add the library reference. I do it as described on the Android Developers website (here) but it only copies the classes across to a folder called "actionbar_src". The error then comes when it tries to find the library's resources within the classes, which it didn't copy across. What am I doing wrong?
Here's a screenshot:
Under 'Java Build Path -> Projects' did you also add the project there? I find I have to do both for the project to compile and run.