Revert "Improve performance of expandIP, and readable"

This reverts commit 2baae144

acl/src/main/java/org/apache/rocketmq/acl/common/AclUtils.java

@@ -206,31 +206,61 @@ public class AclUtils {
     }
 
     public static String expandIP(String netaddress, int part) {
-        // expand netaddress
-        int separatorCount = StringUtils.countMatches(netaddress, ":");
-        int padCount = part - separatorCount;
-        if(padCount > 0){
-            StringBuilder padStr = new StringBuilder(":");
-            for(int i = 0; i < padCount; i++){
-                padStr.append(":");
+        boolean compress = false;
+        int compressIndex = -1;
+        String[] strArray = StringUtils.split(netaddress, ":");
+        ArrayList<Integer> indexes = new ArrayList<>();
+        for (int i = 0; i < netaddress.length(); i++) {
+            if (netaddress.charAt(i) == ':') {
+                if (indexes.size() > 0 && i - indexes.get(indexes.size() - 1) == 1) {
+                    compressIndex = i;
+                    compress = true;
+                }
+                indexes.add(i);
             }
-            netaddress = StringUtils.replace(netaddress, "::", padStr.toString());
         }
 
-        // pad netaddress
-        String[] strArray = StringUtils.splitPreserveAllTokens(netaddress, ":");
         for (int i = 0; i < strArray.length; i++) {
-            if(strArray[i].length() < 4){
-                strArray[i] = StringUtils.leftPad(strArray[i], 4, '0');
+            if (strArray[i].length() < 4) {
+                strArray[i] = "0000".substring(0, 4 - strArray[i].length()) + strArray[i];
             }
         }
 
-        // output
         StringBuilder sb = new StringBuilder();
-        for (int i = 0; i < strArray.length; i++) {
-            sb.append(strArray[i]);
-            if (i != strArray.length - 1) {
-                sb.append(":");
+        if (compress) {
+            int pos = indexes.indexOf(compressIndex);
+            int index = 0;
+            if (!netaddress.startsWith(":")) {
+                for (int i = 0; i < pos; i++) {
+                    sb.append(strArray[index]).append(":");
+                    index += 1;
+                }
+            }
+            int zeroNum = part - strArray.length;
+            if (netaddress.endsWith(":")) {
+                for (int i = 0; i < zeroNum; i++) {
+                    sb.append("0000");
+                    if (i != zeroNum - 1) {
+                        sb.append(":");
+                    }
+                }
+            } else {
+                for (int i = 0; i < zeroNum; i++) {
+                    sb.append("0000").append(":");
+                }
+                for (int i = index; i < strArray.length; i++) {
+                    sb.append(strArray[i]);
+                    if (i != strArray.length - 1) {
+                        sb.append(":");
+                    }
+                }
+            }
+        } else {
+            for (int i = 0; i < strArray.length; i++) {
+                sb.append(strArray[i]);
+                if (i != strArray.length - 1) {
+                    sb.append(":");
+                }
             }
         }
         return sb.toString().toUpperCase();