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What is the difference between checked and unchecked exceptions under Java coding standards?
Checked exceptionUnchecked exception
Extends Exception (not RuntimeException); the compiler forces callers to catch or declare it.Extends RuntimeException; the compiler does not require handling.
Used for recoverable, expected failures the caller can reasonably act on.Used for programming errors or conditions the caller cannot meaningfully recover from.
Example: IOException from a file read.Example: IllegalArgumentException from a bad method call.

The coding standard for choosing between them is based on recoverability, not severity: if the immediate caller has a genuine, sensible recovery path - retrying, falling back to a default, prompting the user again - a checked exception documents that possibility explicitly in the method signature.

If the failure signals a bug or an unrecoverable state, standards favor an unchecked exception, because forcing every caller up a long stack to catch or declare something they cannot actually act on just adds boilerplate without adding safety.

A checked exception is distinguished from an unchecked one by:
Standards favor an unchecked exception when the failure:

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