How to force garbage collection in Java?

Question

Is it possible to force garbage collection in Java, even if it is tricky to do? I know about System.gc(); and Runtime.gc(); but they only suggest t

Answer 1

On OracleJDK 10 with G1 GC, a single call to System.gc() will cause GC to clean up the Old Collection. I am not sure if GC runs immediately. However, GC will not clean up the Young Collection even if System.gc() is called many times in a loop. To get GC to clean up the Young Collection, you must allocate in a loop (e.g. new byte[1024]) without calling System.gc(). Calling System.gc() for some reason prevents GC from cleaning up the Young Collection.