How is the exception handling system organized in Java and how is it structured in terms of nesting levels?

In Java, exception handling is organized using the try-catch-finally construct. Code that might throw an exception is placed inside the try block. Exceptions are caught in catch blocks, where specific types of exceptions can be handled. The finally block is executed always, regardless of whether an exception occurred, and is usually used for resource cleanup.

The hierarchy of exceptions in Java is built from the Throwable class, which has two main subclasses:

• Error — errors that are usually not handled (e.g., OutOfMemoryError).
• Exception — exceptions that can and should be handled.

Exception is divided into:

• Checked exceptions — require mandatory handling or declaration in the method (throws).
• Unchecked exceptions — descendants of RuntimeException, which do not require handling.

Nested try-catch levels can be arbitrary, allowing exception handling to be localized at different levels of the program.