方法收录:3、统计字符串里英文单词的个数并按字典序输出显示（JAVA）

统计字符串里某个字符的个数：

import java.util.HashMap;    
import java.util.StringTokenizer;  
  
public class wordCount {
    public static HashMap wordCount(String string) {
        //用HashMap存放<单词:词频>这样一个映射关系  
        HashMap hashMap=new HashMap();  
        //用正则表达式来过滤字符串中的所有标点符号  
        String regex = "[【】、.。,"!--;:?'\]";   
                string = string.replaceAll(regex, " ");  
                //使用StringTokenizer来分词(StringTokenizer详见JDK文档)  
                StringTokenizer tokenizer = new StringTokenizer(string);  
                while(tokenizer.hasMoreTokens()){  
                    String word=tokenizer.nextToken();  
                    if(!hashMap.containsKey(word)){    
                        hashMap.put(word, new Integer(1));    
                    }else{    
                        int k=hashMap.get(word).intValue()+1;    
                        hashMap.put(word, new Integer(k));    
                    }    
                }  
            //遍历HashMap,输出结果  
            
                return hashMap;
    }  
    public static void main(String[]args) {
        //转化成小写字符串
        String string = "要统计的文本内容".toLowerCase();
    	wordCount test = new wordCount();
    	HashMap hashMap = test.wordCount(string);
    	//将hashmap的内容按字典序列输出
    	Collection keyset= hashMap.keySet();
    	List list = new ArrayList(keyset);
    	Collections.sort(list);
    	for (int i = 0; i < list.size(); i++) {
			 System.out.println( list.get(i) + "：" + hashMap.get(list.get(i)) );
		 } 
    }
}