java中求出数组中每个元素出现的次…

String [] array  =  new String {aa,bb,cc,dd}

 

 Map<String, Integer> map = new HashMap<String, Integer>();  
            
          for (String str : array)  
          {  
              Integer num = map.get(str);  
              num = null == num ? 1 : num + 1;  
              map.put(str, num);  
          }  
          Set set = map.entrySet();  
          Iterator  it = set.iterator();  
          while (it.hasNext())  
          {  
              java.util.Map.Entry <String, Integer> entry = (Entry<String, Integer>)it.next();  
              System.out.println("单词 " + entry.getKey() + " 出现次数 " + entry.getValue());  
          }