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.config;
  
  import com.alibaba.csp.sentinel.log.RecordLog;
  import com.alibaba.csp.sentinel.util.AppNameUtil;
  import com.alibaba.csp.sentinel.util.ConfigUtil;
  import com.alibaba.csp.sentinel.util.StringUtil;
  
  import java.io.File;
  import java.util.Map;
  import java.util.Properties;
  import java.util.concurrent.CopyOnWriteArraySet;
  
  import static com.alibaba.csp.sentinel.util.ConfigUtil.addSeparator;
  
  /**
   * <p>The loader that responsible for loading Sentinel common configurations.</p>
   *
   * @author lianglin
   * @since 1.7.0
   */
  public final class SentinelConfigLoader {
  
      public static final String SENTINEL_CONFIG_ENV_KEY = "CSP_SENTINEL_CONFIG_FILE";
      public static final String SENTINEL_CONFIG_PROPERTY_KEY = "csp.sentinel.config.file";
  
      private static final String DEFAULT_SENTINEL_CONFIG_FILE = "classpath:sentinel.properties";
  
      private static Properties properties = new Properties();
  
      static {
          try {
              load();
          } catch (Throwable t) {
              RecordLog.warn("[SentinelConfigLoader] Failed to initialize configuration items", t);
          }
      }
  
      private static void load() {
          // Order: system property -> system env -> default file (classpath:sentinel.properties) -> legacy path
          String fileName = System.getProperty(SENTINEL_CONFIG_PROPERTY_KEY);
          if (StringUtil.isBlank(fileName)) {
              fileName = System.getenv(SENTINEL_CONFIG_ENV_KEY);
              if (StringUtil.isBlank(fileName)) {
                  fileName = DEFAULT_SENTINEL_CONFIG_FILE;
              }
          }
  
          Properties p = ConfigUtil.loadProperties(fileName);
          if (p != null && !p.isEmpty()) {
              RecordLog.info("[SentinelConfigLoader] Loading Sentinel config from {}", fileName);
              properties.putAll(p);
          }
  
          for (Map.Entry<Object, Object> entry : new CopyOnWriteArraySet<>(System.getProperties().entrySet())) {
              String configKey = entry.getKey().toString();
              String newConfigValue = entry.getValue().toString();
              String oldConfigValue = properties.getProperty(configKey);
              properties.put(configKey, newConfigValue);
              if (oldConfigValue != null) {
                  RecordLog.info("[SentinelConfigLoader] JVM parameter overrides {}: {} -> {}",
                          configKey, oldConfigValue, newConfigValue);
              }
          }
      }
  
  
      public static Properties getProperties() {
          return properties;
      }
  
  }
  