Why is this an issue?

java.util.concurrent.locks.Lock offers far more powerful and flexible locking operations than are available with synchronized blocks. So synchronizing on a Lock throws away the power of the object, and is just silly. Instead, such objects should be locked and unlocked using tryLock() and unlock().

Noncompliant code example

Lock lock = new MyLockImpl();
synchronized(lock) {  // Noncompliant
  //...
}

Compliant solution

Lock lock = new MyLockImpl();
lock.tryLock();
//...

Resources

• CERT, LCK03-J. - Do not synchronize on the intrinsic locks of high-level concurrency objects