java - Java 语言在哪里定义 Throwable 是否被检查？

Question

Exception 和 RuntimeException 都继承自 Throwable，并且没有实现任何接口(interface)来判断它们是否被检查。

哪里指定检查Exception，不检查RuntimeException？它是在语言还是 JVM 中硬连线的吗？

Answer 1

它在 Java Language Specification section 11.1.1 中定义.

Throwable and all its subclasses are, collectively, the exception classes.

Exception is the superclass of all the exceptions from which ordinary programs may wish to recover.

Error is the superclass of all the exceptions from which ordinary programs are not ordinarily expected to recover.

Error and all its subclasses are, collectively, the error classes.

[...]

The class RuntimeException is a direct subclass of Exception. RuntimeException is the superclass of all the exceptions which may be thrown for many reasons during expression evaluation, but from which recovery may still be possible.

RuntimeException and all its subclasses are, collectively, the run-time exception classes.

The unchecked exception classes are the run-time exception classes and the error classes.

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