“Conversion to Dalvik format failed with error 1” on external JAR

第一个答案屡试不爽, 推荐! 1.remove except the "Android X.Y" 2.clean 3.打包

Go to Project » Properties » Java Build Path » Libraries and remove all except the "Android X.Y" (in my case Android 1.5). click OK. Go to Project » Clean » Clean projects selected below » select your project and click OK. That should work.

It is also possible that you have a JAR file located somewhere in your project folders (I had copied the Admob JAR file into my src folder) and THEN added it as a Java Path Library. It does not show up under the Package Explorer, so you don't notice it, but it does get counted twice, causing the dreaded Dalvik error 1.

Another possible reason could be package name conflicts. Suppose you have a packagecom.abc.xyz and a class named A.java inside this package, and another library project (which is added to the dependency of this project) which contains the same com.abc.xyz.A.java, then you will be getting the exact same error. This means, you have multiple references to the same file A.java and can't properly build it.

I solved the problem.

It seems that I have two JAR files on my buildpath that include the same package and classes.

smack.jar and android_maps_lib-1.0.2

Deleting this package from one of the JAR files solved the p