how to use pointers in java code example

Example 1: ARE THERE POINTER IN JAVA

Java does not have pointers.

Example 2: java pointer

There are no pointers in Java. However, there is a Pointer class in JNA, which is very likely NOT what are you looking for.
The only way to get and use pointers is through using Unsafe. The mechanisms are implementation-dependent between JDKs and the Unsafe class may be available at sun.misc.Unsafe or at jdk.internal.misc.Unsafe.