一、intellij 出现“Usage of API documented as @since 1.6+”的解决办法

Usage of API documented as @since 1.6+ This inspection finds all usages of methods that have @since tag in their documentation. This may be useful when development is performed under newer SDK version as the target platform for production

解决办法：

File ->Project Structure->Project Settings -> Modules -> 你的Module名字 -> Sources -> Language Level->选个默认的就行。

二、IDEA Error:java: Compilation failed: internal java compiler error

解决办法：

File-->Setting...-->Build,Execution,Deployment-->Compiler-->Java Compiler 设置相应Module的target bytecode version的合适版本（跟你jkd版本一致），这里我改成1.8版本的。