NoSuchMethodError using commonc codec in Android application-Collection of common programming errors

I think it has something to do with the name conflicts inside Android libraries.

I copied the java source code of Base64 to my project into the the namespace of org.apache.commons.codec.binary. The project compiled without any problem. However, at the runtime in Android simulator, I had the same error, java.lang.NoSuchMethodError: org.apache.commons.codec.binary.Base64.encodeBase64String.

However, after I changed the namespace to com.apache.commons.codec.binary instead of org, the app runs like magic. I guess inside Android implementation, org.apache.commons.codec.binary is used and it doesn’t allow you to use it in your code again.