Java : Explicit garbage collection

Direct system garbage collector call (System.gc()) indicates problems with the application performance.

Garbage collector call is often used to deal with errors, whose cause is unknown. The most likely causes of errors in such cases is incorrect use of mechanisms of synchronization, buffering or race conditions.

According to the Java specification, even a System.gc() call does not guarantee the complete freeing of unused memory: JVM only “expend effort toward recycling unused objects”.