检查HashMap中是否存在特定密钥

 //N o w  J a v a  .   c o m

import java.util.HashMap;

 

public class Main {

 

  public static void main(String[] args) {

    HashMap hMap = new HashMap();

    hMap.put("1","One");

    hMap.put("2","Two");

    hMap.put("3","Three");

   

    boolean blnExists = hMap.containsKey("3");

    System.out.println("3 exists in HashMap ? : " + blnExists);

  }

}