我遇到了错误，因为导入的jar使用的是其他 FluentIterable 来自番石榴 jar的类。我认为类的来源是相同的，因为当我切换回构建路径时，我没有执行 Project-> Clean 并且eclipse仍指向错误的类位置

I was getting the error because the imported jar was using a different FluentIterable class from a guava jar. I thought the class origin is the same because when I switched back the build path, I did not execute a Project->Clean and eclipse was still pointing to the bad class location.