Store Primitive Types in a Collection in Java

//  ww  w  . j  a va 2s .c om
import java.util.HashMap;
import java.util.Map;

public class Main {
  public static void main(String[] argv) throws Exception {
    Map map = new HashMap();

    // Create int wrapper object
    Integer refInt = new Integer(123);

    // Store int in map
    map.put("key", refInt);

    // Get int value from map
    refInt = (Integer) map.get("key");

    // Get the integer value from wrapper object
    int i = refInt.intValue();
  }
}