Java Exception Handling 面试题与答案

问题 21. Explain the 'try-with-resources' syntax introduced in Java 7.

'try-with-resources' simplifies resource management by automatically closing resources that are declared in the try statement. Resources must implement the 'AutoCloseable' interface.

Example:

try (BufferedReader br = new BufferedReader(new FileReader("file.txt"))) { /* code using br */ }

问题 22. Can you rethrow an exception in Java?

Yes, you can rethrow an exception by using the 'throw' statement without an argument inside a catch block.

Example:

catch (Exception e) { /* handling code */ throw e; }

问题 23. What is the purpose of the 'Error' class in Java?

'Error' class represents serious errors that are not meant to be caught or handled by applications.

问题 24. Explain the difference between 'Error' and 'RuntimeException'.

'Error' is meant to indicate serious problems that should not be caught or handled, while 'RuntimeException' is a subclass of 'Exception' and represents exceptions that can be caught and handled.

问题 25. How do you handle custom exceptions in a try-catch block?

You can catch custom exceptions like any other exception by specifying the custom exception type in the catch block.

Example:

try { /* code */ } catch (CustomException ce) { /* handle custom exception */ }