I have a similar issue as in the SO question below, but with scala as my language of choice:
Android project referencing "normal" java project in eclipse since sdk tools update 17
Basically, if I setup a regular android project using java,
a regular java library project and a 'glue' android library project as described in the link above, everything works fine and I can use code from my referenced regular java project.
However, if I try to repeat the same procedure using scala projects I get a noclassdeffound exception when launching. (If I move the code form the regular referenced project into the main android project the error disappears and everything works.)
Any hints on what to look for? Anyone doing the same with success?
Related
I'm trying to create a library that reuses some of my existing (plain Java) code. The library was working fine on its own but when I moved it into the bigger project I ran into some issues:
Android studio now "opens" the super-project instead of the Android one
Android studio no longer recognizes Android files properly, they just get tagged as "Java Classes" with the circle-C icon
My demo application is no longer executable either
How can this be set up so that android studio doesn't really show the super project?
I suggest you can upload your library to github and add it as dependency of your bigger project like :
dependencies {
implementation 'com.github.yourSampleLib:yourVersion'
}
I have some projects in my workspace :
AndroidMonitoring # an android application
MonitoringModel # an android library project
DataServlet # servlet project
AndroidMonitoring (which depends on MonitoringModel,
)
compiles and runs just fine but I need the MonitoringModel classes to be available also in the DataServlet project. I added the Model as a dependency in the Java Build path of the DataServlet project but I get :
java.lang.NoClassDefFoundError: gr/uoa/di/monitoring/model/Battery
gr.uoa.di.monitoring.server.servlets.DataCollectionServlet.doGet(DataCollectionServlet.java:20)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
I need the Model to be an Android library project as it contains android classes - but also contains the methods to parse the files in the servlet - is it possible ? How should I set this up ?
EDIT : MonitoringModel is here
Solved !
remove the dependency from DataServlet's java build path
go to the MonitoringModel project and remove the library attribute, run it as an Android app remake it into a library (from here) Clean the MonitoringModel project
grab the monitoringmodel.jar from bin/ and drop it into the DataServlet/WEB-INF/lib
refresh and run on server
done !
Will try and improve on this hack (linking to an external jar did not seem to work btw) - any better ideas will be accepted as an answer - however closing this for now.
EDIT : apparently step 3. can be substituted by creating a hard link from DataServlet/WEB-INF/lib/monitoringmodel.jar to monitoringmodel.jar - still testing this as some action sequences break the link methinks. Symbolic links do not seem to work though - reported this as a bug
EDIT2 : the steps below seem to work too - but I leave the manual procedure as it definitely works
remove the dependency from DataServlet's java build path
Hard link the monitoringmodel.jar from bin/ and to the DataServlet/WEB-INF/lib. I used shell link extension but this :
mklink /H c:\path\to\WebContent\WEB-INF\lib\monitoringmodel.jar c:\path\to\bin\monitoringmodel.jar
should also work
Now everytime you make a change in monitoring model the jar is updated. You only have to refresh the servlet project (will be redeployed on server on its own by default)
Clarification : of course the servlet project is not meant to use android.* classes - this was not my issue - my issue was to have the model code in one place and this place had to be an android library
First of all - I believe Java Web Project will not work with any of Android specific classes due to many reasons.
If your MonitoringModel contains some Java code that you want to share between Android and Web application you can extract it to separate Java project and use a Link Source option in Properties->Build Path to link it to both projects.
I've been playing with a Java's Magento connector called magja (https://github.com/magja/magja) in a 'normal' Java project. And everything were working fine till this point.
After that, I started a simple Android application that would use the magja code to consume such information from Magento.
The question is: how should I configure the my Android project to deal with a 'normal' Java project (not a library)? This another project uses several xml files to configuration and Maven to deal with dependencies. How this impacts my Android App?
Thanks a lot!
EDITED
Actualy, I've already tried this approach (Android project unable to reference other project in eclipse), but always when the app tries to run the 'project B' (magja) code, it causes a
java.lang.NoClassDefFoundError: org.apache.commons.httpclient.params.HttpConnectionManagerParams
I believe it's related to some .jar files that magja uses. It looks like that I would solve the problem if I could share such library between the projects.
I'm just getting started in Android development, and use Netbeans with NBAndroid and SDK 17.
I'd like to use the same Java source code in my Java and Android app.
http://developer.android.com/guide/developing/projects/projects-eclipse.html says how to do it in Eclipse (although it is sketchy on the .JAR connection thing), but I can't seem to make it work in NB.
Based on that link, My understanding is that the correct setup for the Android app is an Android Application project which references an Android Library project which in turn references a .JAR library produced by a Java Library project. I could then also have a Java Application project referring to the same Java Library project.
So, I've set up this project structure... I have an AndroidApp project which is a basic HelloAndroid Activity in a com.ex package. This project includes an AndroidLib library project in the Libraries folder. I also have a LibClass.java file which defines a simple LibClass class which has one function getText() that just returns a String to be displayed. The MainActivity in the AndroidApp calls this to get the String to output.
When I put LibClass.java directly into the AndroidLib project, everything is fine.
But what I want to do is to share the source code with Java.
So I want to move the LibClass.java into the JavaLib library, whose .JAR file is included in the AndroidLib project. However, when I tried that, I get an error in the MainActivity class, complaining it can't find LibClass. Looking at the Projects window, I can see LibClass.class inside the com.ex package in the JavaLib.jar in the Libraries folder of the AndroidLib project. And AndroidLib is visible in the Libraries folder of the AndroidApp project, but it doesn't show any packages or other contents there.
So I feel like I'm just one step away from making this work. Do I need to do something with one or other of the AndroidManifest files perhaps? Or do something with the build.xml files? Or am I on the wrong track altogether?
I'd be really grateful if someone could post a how-to for this.
I'm trying something similar; I've got Java EE projects, built using Eclipse, and I'm trying to utilize some of that code from my Android projects. This should give me a shared codebase rather than a bunch of confusing SVN externals which I've had to endure before.
Rather than creating JAR files I've found that working with the source and building for the platform works best (well, it has been working but I've got a problem with it at the moment). So, what I'm doing is:
c:\MySvnFolderStructure\MyJavaProjectFolder\src\ (and then all the source under that)
c:\MySvnFolderStructure\MyJavaProjectFolder\android\ (and all the Eclipse Android project gubbins)
c:\MySvnFolderStructure\MyJavaProjectFolder\jee\ (and all the Eclipse JEE project gubbins)
The Android and Java EE projects do not have their own src folders, they both link to the src folder in their parent folder. What this means is that each of the Java implementations is building its own byte code version from the source, and using its own external libraries (like the Apache HTTP ones, for example).
Naturally they can't share stuff like awt (as mentioned in another post), but there's plenty of stuff that does cross-over especially if it's core Java classes that are being used.
Also, it's proving a bit tricky writing JUnit tests as there needs to be some duplication of the test code at the moment because the Android ones need extra instrumentation, but I'm working on it.
Also, see this post about relative paths in Eclipse, which means the folders can be checked-out to different places on different machines (like we all do with our version control check-outs) and still be shared.
if I understand your situation correct, you are trying to use a custom java library for both your android and java applications.
For this scenario, you can build the java library first. Instead of adding the java library jar as android library, you can drop the jar directly inside the libs folder of android project and add it to android project's build path.
If you are using ANT scripts for building the java library jar , you can consider adding the source files also as part of jar. This will help you get code assistance when you develop the android part. But this part is purely optional.
The problem is that the Java platform in Android is different from the JDK platform.
In particular, the .JAR library CANNOT refer to anything that is not icluded in the Android platform. An example of things you can't refer to is java.awt.* (except you can have java.awt.fonts).
There is also a difference between JDK String and Android String -- Android does not implement the isEmpty() method.
According to this SDK guide, unit-testing a Library project can be achieved by creating a standard application project, reference the Library project and then instrument the application for unit testing.
However, when I do this and launch the test application I get the message
No tests found with test runner 'JUnit 3'.
I'm using Eclipse and the Android ADT plugin, all latest versions.
Note: the projects compile just fine. The test project also installs fine to the emulator. But in the console I can see that it looks for <library>.apk, which of course doesn't exist since I'm compiling this as a library into the test project.
Anyone got this to work? And if so, what is the trickery here?
Update: after discovering and fixing a problem, which was actually including the test classes (!), the test runner now can find all tests. But, all the tests fail with the following exceptions:
java.lang.NoClassDefFoundError: <nameOfClassInLibraryProject>
nameOfClassInLibraryProject are classes defined in the library project. These classes should be compiled into the test project, and indeed, everything compiles just fine. But when running the test project, the runtime doesn't seem to find the library classes.
After much fiddling and wasted time in Eclipse I have managed to get Android Library projects to work.
According to the Working with Library Projects article:
Instead, you must compile the library indirectly, by referencing the library from a dependent application's build path, then building that application.
The problem was that I interpreted this to mean that the library project should be added to the Projects tab in Java Build Path. Doing this makes the test project compile since the library code is obviously available to the compiler. But since the library is not compiled into a .jar or .apk in itself, the library classes are never deployed to the device.
The solution is to not add the library project to Projects, rather on the Source tab, add the library /src folder using the Link Source... button. And yes, it is the library src folder, not the library project root, that must be linked into the test project.