Is there any difference in memory allocation using the new opeartor in the java shell class?

Line:

Integer r = 9;

actually becomes:

Integer r = Integer.valueOf(9);

due to autoboxing that retrieves a cached Integer object. If you check the JLS section 5.1.7 in Boxing Conversions, it states that Integer values ​​between -128 and 127 are cached. In practice, the first call Integer.valueOf()(which includes auto-boxing events) initializes a cache that can take into account different amounts of memory.

public class Sizer {

  public static void main(String [] args) throws Exception {
    Runtime r = Runtime.getRuntime();

    // Pre-instantiate variables
    long memoryBefore = 0;
    long memoryAfter = 0;
    int loops = 10;

    runGC(r, loops);
    memoryBefore = getMemoryUsage(r);

//     Long lo = new Long(1);
    TestClass in = new TestClass(); 

    runGC(r, loops);
    memoryAfter = getMemoryUsage(r);

    System.out.println("Diff in size is " + (memoryAfter - memoryBefore));
  }

  public static void runGC(Runtime r, int loops) throws Exception {
    for(int i=0; i<loops; i++) {
      r.gc();
      Thread.sleep(2000);
    }
  }

  public static long getMemoryUsage(Runtime r) throws Exception {
    long usedMemory = r.totalMemory() - r.freeMemory();
    System.out.println("Memory Usage: " + usedMemory);
    return usedMemory;
  }

}