content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package com.alibaba.csp.sentinel.util;
  
  import java.lang.reflect.Method;
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  
  /***
   * Util class for processing {@link Method}.
   *
   * @author youji.zj
   */
  public final class MethodUtil {
  
      private static final Map<Method, String> methodNameMap = new ConcurrentHashMap<Method, String>();
  
      private static final Object LOCK = new Object();
  
      /**
       * Parse and resolve the method name, then cache to the map.
       *
       * @param method method instance
       * @return resolved method name
       */
      public static String resolveMethodName(Method method) {
          if (method == null) {
              throw new IllegalArgumentException("Null method");
          }
          String methodName = methodNameMap.get(method);
          if (methodName == null) {
              synchronized (LOCK) {
                  methodName = methodNameMap.get(method);
                  if (methodName == null) {
                      StringBuilder sb = new StringBuilder();
  
                      String className = method.getDeclaringClass().getName();
                      String name = method.getName();
                      Class<?>[] params = method.getParameterTypes();
                      sb.append(className).append(":").append(name);
                      sb.append("(");
  
                      int paramPos = 0;
                      for (Class<?> clazz : params) {
                          sb.append(clazz.getCanonicalName());
                          if (++paramPos < params.length) {
                              sb.append(",");
                          }
                      }
                      sb.append(")");
                      methodName = sb.toString();
  
                      methodNameMap.put(method, methodName);
                  }
              }
          }
          return methodName;
      }
  
      /**
       * For test.
       */
      static void clearMethodMap() {
          methodNameMap.clear();
      }
  }
  