新增方法

panda-code/src/main/java/org/panda/code/uitl/StringUtil.java

@@ -1,6 +1,8 @@
 package org.panda.code.uitl;
 
 
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Random;
 import java.util.concurrent.ThreadLocalRandom;
 
@@ -138,12 +140,27 @@ public class StringUtil {
         return  null;
     }
 
-    public static void main(String[] args) {
 
-        String text = "你好[xxxxx]";
-        System.out.println(text.indexOf("["));
+    /**
+     * 统计字符在字符串出线次数
+     * @param str
+     * @param ch
+     * @return
+     */
+    public static int countChar(String str,char ch){
+        char[] chars = str.toCharArray();
+        Map<Character,Integer> countMap = new HashMap<>(chars.length);
+        for (char cha:chars){
+            if (countMap.containsKey(cha)){
+                int contNum = countMap.get(cha);
+                contNum++;
+                countMap.put(cha,contNum);
+            }else {
+                countMap.put(cha,new Integer(1));
+            }
+        }
 
+        return countMap.get(ch);
     }
 
-
 }