Add non-Android library project to Android app in Eclipse

Question

I have three projects in the Eclipse workspace:

• A maven-based library project that generates a .jar file. This project contains our main code.
• Java desktop application based on maven. This application is library dependent.
• The Android application that we just started to create. This is not yet stunned.

I want the Android application to use the library project as a dependency.

I read several answers to similar questions about adding a library file dependency to an Android application, and I tried to execute them:

Method # 1:

Project-> Properties-> Java Build Path-> Projects → Add and Add Library Project.

Now I can use the classes from the library project. The compiler does not generate any warnings. However, when I run the application on the emulator, I get an error not defined by the class.

Method No. 2:

Copy the generated .jar file to the "libs" directory of the Android application.

It works. Class exception thrown. However, I cannot connect the source and therefore cannot go through the library code. In addition, every time the source changes, I will have to manually copy the .jar file.

Method 3:

Go to the Library Project Properties section. In the left pane you will see "Android". Select it and check the "IsLibrary" box.

In my case, however, there is no “Android” property in the left pane. I assume that this property is displayed only if it is a real Android library project.

I am stuck. I would appreciate it if someone could tell me how best to deal with this situation.

Here is a summary of what I want to achieve:

• The same library project that will be used in the desktop application as an Android application.
• In an Android app, source code debugging should work.
• If there are any changes to the source code in the library application, the Android application should automatically receive new changes (instead, I try to drag the new .jar file into the libs folder every time).

Answer 1

Method # 1 seems still available, but you need to study why you get this ClassNotFoundException - unzip the APK (since this is an archive), delete it and see why the library classes are not included.

From experience, if you work with Eclipse, I believe that you get this exception because you did not check the library as exported when you add it to an Android project - after you added it for assembly, follow these steps: Project Props → Build path → Order and export, here make sure that the library project is selected. There is a known issue / disappointment regarding this ClassNotFoundException, and the workaround is selecting the export tab. I believe that this article contains more or this topic.

When it comes to debugging jar code, you need to include a properties file in the libs folder that has the same name as your jar file (for example, if the jar file is mylib.jar library, you need to have a mylib.jar.properties ) This file should have an src entry pointing to the path in which the source code lives (either as a jar file or file system). Eclipse is a little dumb when you add this file to restart it. It may contain a doc entry that also indicates where javadoc lives. Here is my example:

 src=../docs/spring-android-rest-template-1.0.1.RELEASE-sources.jar doc=../docs/spring-android-rest-template-1.0.1.RELEASE-javadoc.jar