graph TD
A[Throwable] --> B[Exception] 
A --> C[Error]
B --> D[Checked Exception-编译时异常]
B --> E[Unchecked Exception-运行时异常]
C --> F(OutOfMemoryError 

 StackOverFlowError 
...)
D --> G(IOException 

 ClassNotFoundException 

 FileNotFoundException 

 ... )
E --> H(NullPointerException 

 IndexOutOfBoundsException 

 ClassCastException 

...)