content: /*
   * Copyright 1999-2022 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.nacos.common.utils;
  
  /**
   * A convenient tool to get property or env value.
   *
   * @author Pixy Yuan on 2022/3/24
   */
  public class PropertyUtils {
  
      private PropertyUtils() {
      }
      
      private static final String PROCESSORS_ENV_NAME = "NACOS_COMMON_PROCESSORS";
      
      private static final String PROCESSORS_PROP_NAME = "nacos.common.processors";
      
      /**
       * Get system env or property value.
       *
       * <p>If {@link System#getenv()} has no value for {@code envName},
       * return {@link System#getProperty(String)}.
       */
      public static String getProperty(String propertyName, String envName) {
          return System.getenv().getOrDefault(envName, System.getProperty(propertyName));
      }
      
      /**
       * Get system env or property value.
       *
       * <p>If {@link System#getenv()} has no value for {@code envName},
       * return {@link System#getProperty(String, String)} or {@code defaultValue}.
       */
      public static String getProperty(String propertyName, String envName, String defaultValue) {
          return System.getenv().getOrDefault(envName, System.getProperty(propertyName, defaultValue));
      }
      
      /**
       * Get processors count maybe preset by env or property.
       */
      public static int getProcessorsCount() {
          int processorsCount = 0;
          String processorsCountPreSet = getProperty(PROCESSORS_PROP_NAME, PROCESSORS_ENV_NAME);
          if (processorsCountPreSet != null) {
              try {
                  processorsCount = Integer.parseInt(processorsCountPreSet);
              } catch (NumberFormatException ignored) {
              }
          }
          if (processorsCount <= 0) {
              processorsCount = Runtime.getRuntime().availableProcessors();
          }
          return processorsCount;
      }
  }
  