关于java：在前面的catch块中处理的rethrowing异常

rethrowing exception handled in preceding catch block

在iIC站点上写入(http://docs.oracle.com/javase/7/docs/technotes/guides/language/catch-multiple.html#rethrow)

In detail, in Java SE 7 and later, when you declare one or more
exception types in a catch clause, and rethrow the exception handled
by this catch block, the compiler verifies that the type of the rethrown exception meets the following conditions:

-The try block is able to throw it.

-There are no other preceding catch blocks that can handle it.

-It is a subtype or supertype of one of the catch clause's exception parameters.

请注意第二点(There are no other preceding catch blocks that can handle it)

研究以下代码：

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static private void foo() throws FileNotFoundException {
try {
throw new FileNotFoundException();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
throw e;
}
}

这段代码编译得很好。根据我的观点，在阅读了上述文章的引言后，我希望看到编译器会验证它，并且我会得到编译器错误。

第二点我理解错了吗？

这是非常好的，因为FileNotFoundException是从IOException衍生而来的，而且因为你从不太具体的到更具体的，所以不应该有任何问题。

编辑：

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static private void foo() throws FileNotFoundException {
try {
throw new FileNotFoundException();
} catch (IOException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
throw e;
}
}