UnusedException
This catch block catches an exception and re-throws another, but swallows the caught exception rather than setting it as a cause. This can make debugging harder.

The problem

Catching an exception and throwing another is a common pattern. This is often used to supply additional information, or to turn a checked exception into an unchecked one.

  try {
    ioLogic();
  } catch (IOException e) {
    throw new IllegalStateException(); // BAD
  }

Throwing a new exception without supplying the caught one as a cause means the stack trace will terminate at the catch block, which will make debugging a possible fault in ioLogic() far harder than is necessary.

Prefer wrapping the original exception instead,

  try {
    ioLogic();
  } catch (IOException e) {
    throw new IllegalStateException(e); // GOOD
  }

Suppression

If the exception is deliberately unused, rename it unused to suppress this diagnostic.

static <T extends Enum<T>> T tryForName(Class<T> enumType, String name) {
  try {
    return Enum.valueOf(enumType, name);
  } catch (IllegalArgumentException unused) {
    return null;
  }
}

Otherwise, suppress false positives with @SuppressWarnings("UnusedException") on the ignored exception. Consider also adding a comment to explain why the exception should not be propagated.

  try {
    ...
  } catch (@SuppressWarnings("UnusedException") IOException e) {
    throw new IllegalStateException();
  }