统计输入任意字符串中字符的个数

 1 import java.util.ArrayList;
 2 import java.util.HashSet;
 3 import java.util.Iterator;
 4 import java.util.List;
 5 import java.util.Set;
 6
 7 /**
 8  *
 9  * @author trfizeng
10  */
11 public class CountStr {
12
13     //统计任意字符串出现的次数
14     public static List<String> countStr(String str) {
15         //用于存放生成要检测的字符串的字典
16         Set<String> base = new HashSet<String>();
17         //用于存放输入的字符串的每个字符
18         List<String> totalStr = new ArrayList<String>();
19         //用于存放每个字符出现的次数
20         List<String> couList = new ArrayList<String>();
21         //把字符串转化为字符数组
22         char [] tempChar = str.toCharArray();
23
24         //初始化字典和要统计的字符
25         for (int i = 0; i < tempChar.length; i++) {
26             base.add(tempChar[i]+"");
27             totalStr.add(tempChar[i]+"");
28         }
29
30         Iterator<String> it = base.iterator();
31         //初始化每个字符出现的次数
32         while (it.hasNext()) {
33             String string = (String) it.next();
34             couList.add(string + ":" + 0);
35         }
36
37         //用于计数每个字符出现的次数
38         int c = 0;
39         //开始遍历
40         for (int i = 0; i < totalStr.size(); i++) {
41             String tC = totalStr.get(i);
42             Iterator<String> ite = base.iterator();
43             while (ite.hasNext()) {
44                 String obj = ite.next();
45                     //判断字符是否出现
46                     if (tC.equals(obj)) {
47                         for (int j = 0; j < couList.size(); j++) {
48                             String cL = couList.get(j);
49                             if (cL.startsWith(obj)) {
50                                 //把原来出现的次数拿出来+1
51                                 c = Integer.parseInt(cL.substring(cL.lastIndexOf(":")+1,cL.length()));
52                                 c++;
53                                 //从新设置出现的次数
54                                 couList.set(j, obj + ":" + (c));
55                             }
56                         }
57                     }
58             }
59         }
60         return couList;
61     }
62
63     public static void main(String[] args) {
64         String testStr = "dfe:RRxc.:./哈哈有:";
65         List<String> cList = countStr(testStr);
66         for (int i = 0; i < cList.size(); i++) {
67             System.out.print(cList.get(i) + "  ");
68         }
69          /*
70             *
71             char []c=testStr.toCharArray();
72             Map<String,Integer> m=new HashMap<String, Integer>();
73             for(int i=0;i<c.length;i++){
74                 String cstr=String.valueOf(c[i]);
75                 if(null!=m.get(cstr)){
76                     int count=m.get(cstr);
77                     m.put(cstr, count+1);
78                 }else{
79                     m.put(cstr,1);
80                 }
81             }
82
83             */
84     }
85 }

d:1  /:1  R:2  ::3  c:1  哈:2  f:1  .:2  x:1  有:1  e:1