How can you handle an exception thrown by an initializer/static block? | Java Interview Questions

How can you handle an exception thrown by an initializer block? | static block | Java Interview Questions

In Java, an initializer block, also known as a static initialization block, is a block of code that is run when the class is loaded by the JVM. This block of code is placed within braces {} and preceded by the static keyword.

If an initializer block throws a checked exception, the compiler will give an error because you can't declare it to be thrown and you can't surround the block with a try-catch either, as the initializer block is executed when the class is loaded.

However, if an initializer block throws an unchecked exception (like RuntimeException), the exception will propagate up and terminate the program, unless it is caught higher up in the call stack.

Here's an example:

public class Main {
static {
try {
// Code that might throw an exception
throw new RuntimeException("Exception in initializer block");
} catch (RuntimeException e) {
}
}

public static void main(String[] args) {
}
}

In this code, the initializer block throws a RuntimeException, which is caught and handled within the block itself. The main method is then executed as normal. If the catch block wasn't there, the exception would terminate the program.

Remember that while technically you can catch exceptions within the initializer block, it's usually better practice to avoid throwing exceptions in initializer blocks. If an exception is expected, it's a sign that the code should probably be in a method where it can be properly handled.

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