Android IllegalArgumentException: already added

Question

I have created an android application that uses android-support-v4.jar. Now when I add an android library to this project I get this error when building:

UNEXPECTED TOP-LEVEL EXCEPTION:
java.lang.IllegalArgumentException: already added: Landroid/support/v4/accessibilityservice/AccessibilityServiceInfoCompat$AccessibilityServiceInfoIcsImpl;
[2012-11-08 16:02:31 - ShoppingApp Android] Conversion to Dalvik format failed with error 1

The library I'm trying to add is Facebook SDK, which also happens to use android-support-v4.jar. Only solution for this error I found was removing library from one of build paths, but I can't do it - all options all disabled when I select this jar.

Here is full error trace:

UNEXPECTED TOP-LEVEL EXCEPTION:
java.lang.IllegalArgumentException: already added: Landroid/support/v4/accessibilityservice/AccessibilityServiceInfoCompat$AccessibilityServiceInfoIcsImpl;
    at com.android.dx.dex.file.ClassDefsSection.add(ClassDefsSection.java:123)
    at com.android.dx.dex.file.DexFile.add(DexFile.java:163)
    at com.android.dx.command.dexer.Main.processClass(Main.java:486)
    at com.android.dx.command.dexer.Main.processFileBytes(Main.java:455)
    at com.android.dx.command.dexer.Main.access$400(Main.java:67)
    at com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:394)
    at com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:245)
    at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:131)
    at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:109)
    at com.android.dx.command.dexer.Main.processOne(Main.java:418)
    at com.android.dx.command.dexer.Main.processAllFiles(Main.java:329)
    at com.android.dx.command.dexer.Main.run(Main.java:206)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.android.ide.eclipse.adt.internal.build.DexWrapper.run(DexWrapper.java:180)
    at com.android.ide.eclipse.adt.internal.build.BuildHelper.executeDx(BuildHelper.java:703)
    at com.android.ide.eclipse.adt.internal.build.builders.PostCompilerBuilder.build(PostCompilerBuilder.java:577)
    at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:728)
    at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
    at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:199)
    at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:321)
    at org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:396)
    at org.eclipse.core.internal.resources.Project$1.run(Project.java:618)
    at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2344)
    at org.eclipse.core.internal.resources.Project.internalBuild(Project.java:597)
    at org.eclipse.core.internal.resources.Project.build(Project.java:124)
    at com.android.ide.eclipse.adt.internal.project.ProjectHelper.doFullIncrementalDebugBuild(ProjectHelper.java:1000)
    at com.android.ide.eclipse.adt.internal.launch.LaunchConfigDelegate.launch(LaunchConfigDelegate.java:147)
    at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:855)
    at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:704)
    at org.eclipse.debug.internal.ui.DebugUIPlugin.buildAndLaunch(DebugUIPlugin.java:1047)
    at org.eclipse.debug.internal.ui.DebugUIPlugin$8.run(DebugUIPlugin.java:1251)
    at org.eclipse.core.internal.jobs.Worker.run(Worker.java:53)
[2012-11-08 16:02:31 - ShoppingApp Android] Dx 1 error; aborting
[2012-11-08 16:02:31 - ShoppingApp Android] Conversion to Dalvik format failed with error 1

Answer 1

The build process checks the checksum of every jar and raises this error if the jar is found twice and the jars have different checksums.

This means you have the same library twice but two different versions of the jar file, which doesn't make sense.

If you added a library project, you don't need the support library in your app, you can delete it as it is inherited from the project library.

You might want to update the jar of the support library into the library project.

Edit: you don't play with the build path anymore, your libraries folders should be "libs" and it will appear in the project as "Android dependencies". Then you remove the jar from your libs folder of your app, and maybe update the one from the library project.

Answer 2

This error means that you have some classes included more than once in your build. I've solved quite the same problem with mvn dependencies in eclipse by unchecking "Export maven decencies" in Project configuration/Java Build Path/Export.