这种提示的意思是说,引用的文件重复了.在引用json解析库中,clean工程的时候,报错说:
Unable to execute dex: Multiple dex files define Lorg/apache/commons/collections/Buffer;
Conversion to Dalvik format failed: Unable to execute dex: Multiple dex files define Lorg/apache/commons/collections/Buffer;
后来仔细一看,原来commons-beanutils-1.7.0.jar和commons-collections-3.2.jar中都有org.apache.commons.collections.Buffer.class.
Android - Unable to execute dex: Multiple dex files define
原文：http://www.cnblogs.com/listened/p/4263428.html