checked unchecked Exception

https://docs.oracle.com/javase/specs/jls/se8/html/jls-11.html

That is, the checked exception classes are Throwable and all its subclasses other than RuntimeException and its subclasses and Error and its subclasses.

两类：checked exceptions 和 unchecked exception 。

        "s".getBytes("utf-8");
        
        Integer.valueOf("s");

一个是编译期间（compile-time），必须处理，不然编译不通过。

一个是运行期间（run-time）

常见的运行时异常：

• ClassCastException
• IndexOutOfBoundsException
• NullPointerException
• IllegalArgumentException
• AuthenticationException
• AuthorizationException
• DuplicateKeyException