java统计字符串单词个数的方法解析

/** 
   * 统计各个单词出现的次数 
   * @param text 
   */ 
  public static void findEnglishNum(String text){ 
   //找出所有的单词 
   String[] array = {".", " ", "?", "!"}; 
   for (int i = 0; i < array.length; i++) { 
    text = text.replace(array[i],","); 
   } 
   String[] textArray = text.split(","); 
   //遍历 记录 
   Map<String, Integer> map = new HashMap<String, Integer>(); 
   for (int i = 0; i < textArray.length; i++) { 
    String key = textArray[i]; 
    //转为小写 
    String key_l = key.toLowerCase(); 
    if(!"".equals(key_l)){ 
     Integer num = map.get(key_l); 
     if(num == null || num == 0){ 
      map.put(key_l, 1); 
     }else if(num > 0){ 
      map.put(key_l, num+1); 
     } 
    } 
   } 
   //输出到控制台 
   System.out.println("各个单词出现的频率为："); 
   Iterator<String> iter = map.keySet().iterator(); 
   while(iter.hasNext()){ 
    String key = iter.next(); 
    Integer num = map.get(key); 
    System.out.println(key + "\n\t\t" + num + "次\n-------------------"); 
   } 
  }

public static void main(String[] args) { 
   String text = "Welcome welcome to ADempiere, a commons-based peer-production of Open Source ERP Applications. This Wiki is for the global community to contribute and share know-how and domain expertise. We hope you can find as much open information and participate in making it most usable for everyone. This project has a bazaar of Citizens with a Community Council Team which work in theFunctional Team and Technical Team along the Software Development Procedure supported and funded by the foundation ADempiere"; 
   findEnglishNum(text);   }