session

 public static void main(String[] args) {
     new Test().doTest();
}
 public void doTest(){
    Integer M = new Integer(1024 * 1024 * 1); 
    byte[] bytes = new byte[1 * M]; 
    bytes = null;  
    System.gc();   
     System.out.println();
    bytes = new byte[1 * M];  
    bytes = new byte[1 * M];  
    System.gc();
    System.out.println();
}