Difference between system.gc() and runtime.gc()

From looking at the source code: System.gc() is implemented as

Runtime.getRuntime().gc();

So it's just a convenience method.

Both are same. System.gc() is effectively equivalent to Runtime.gc(). System.gc()internally calls Runtime.gc().

The only difference is System.gc() is a class method where as Runtime.gc() is an instance method. So, System.gc() is more convenient.

See the docs

System.gc() is equivalent to Runtime.getRuntime().gc()