When the return value of a function call contain the operation status code, this value should be tested to make sure the operation completed successfully.
This rule raises an issue when the return values of the following are ignored:
java.io.File
operations that return a status code (except mkdirs
) Iterator.hasNext()
Enumeration.hasMoreElements()
Lock.tryLock()
Condition.await*
methods CountDownLatch.await(long, TimeUnit)
Semaphore.tryAcquire
BlockingQueue
: offer
, remove
public void doSomething(File file, Lock lock) { file.delete(); // Noncompliant // ... lock.tryLock(); // Noncompliant }
public void doSomething(File file, Lock lock) { if (!lock.tryLock()) { // lock failed; take appropriate action } if (!file.delete()) { // file delete failed; take appropriate action } }