Error:编译器 (1.8.0_31) 中出现异常错误。 如果在 Bug Parade 中没有找到该错误, 请在 Java Developer Connection (http://java.sun.com/webapps/bugreport) 中建立 Bug。请在报告中附上您的程序和以下诊断信息。谢谢。

com.sun.tools.javac.code.Symbol$CompletionFailure: 找不到rx.Observable的类文件

FAILURE: Build failed with an exception.

* What went wrong:

Execution failed for task ':app:compileDebugJavaWithJavac'.

> Compilation failed; see the compiler error output for details.

* Try:

Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.