在 Java 中捕获并声明异常？

Question

In Java, if I declare and caught an exception, can I handle the exception in a caller anyway? Or it needs not to be caught to handle it by caller?

class A {
  void first() throws Exception { 
    try {
      throw new Exception("my exception")
    } catch (Exception e) {
      log.message("Error in first()", e.getCouse)
      throw e
    }
  }
}

class B {
  Result second(A a) {
    try {
      a.first()
    } catch (Exception e) {
      log.message("Caught in B class", e.message)
      return new Result(result: null, error: e.message)
    }
  }

  second(A a)
}

Answer 1

You can simply rethrow the exception you've caught (obviously the surrounding method has to permit this via its signature etc.). The exception will maintain the original stack trace.

catch (WhateverException e) {
    throw e;
}

You can also wrap the exception in another one AND keep the original stack trace by passing in the Exception as a Throwable as the cause parameter:

try
{
   ...
}
catch (Exception e)
{
     throw new YourOwnException(e);
}