Pre-compile regex in Rule.java

Author: sliceofapplepie

api/src/main/java/org/apache/cloudstack/acl/Rule.java

@@ -25,16 +25,18 @@
 
 public final class Rule {
     private final String rule;
+    private final Pattern compiledPattern;
     private final static Pattern ALLOWED_PATTERN = Pattern.compile("^[a-zA-Z0-9*]+$");
 
     public Rule(final String rule) {
         validate(rule);
         this.rule = rule;
+        this.compiledPattern = Pattern.compile(rule.toLowerCase().replace("*", "\\w*"));
     }
 
     public boolean matches(final String commandName) {
         return StringUtils.isNotEmpty(commandName)
-                && commandName.toLowerCase().matches(rule.toLowerCase().replace("*", "\\w*"));
+                && compiledPattern.matcher(commandName.toLowerCase()).matches();
     }
 
     public String getRuleString() {