content: /*
   * Copyright 1999-2017 Alibaba Group.
   *
   * 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.p3c.pmd.lang.java.util.namelist;
  
  import java.io.IOException;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Properties;
  
  import com.google.gson.Gson;
  import com.google.gson.reflect.TypeToken;
  
  /**
   * @author changle.lq
   * @date 2017/03/27
   */
  public class NameListServiceImpl implements NameListService {
  
      private static final String NAME_LIST_PROPERTY_FILE_NAME = "namelist.properties";
      private static final Properties PROPERTIES = initProperties();
      private static final String SEPARATOR = "_";
  
      private static Properties initProperties() {
          LinkedProperties props = new LinkedProperties();
          ClassLoader classLoader = NameListServiceImpl.class.getClassLoader();
          try {
              props.load(classLoader.getResourceAsStream(NAME_LIST_PROPERTY_FILE_NAME));
          } catch (IOException ex) {
              throw new IllegalStateException("Load namelist.properties fail", ex);
          }
          return props;
      }
  
      @Override
      public List<String> getNameList(String className, String name) {
          Gson gson = new Gson();
          return gson.fromJson((String)PROPERTIES.get(className + SEPARATOR + name),
              new TypeToken<List<String>>() {}.getType());
      }
  
      @Override
      public <K, V> Map<K, V> getNameMap(String className, String name, Class<K> kClass, Class<V> vClass) {
          Gson gson = new Gson();
          return gson.fromJson((String)PROPERTIES.get(className + SEPARATOR + name),
              new TypeToken<Map<K, V>>() {
              }.getType());
      }
  
      private static class LinkedProperties extends Properties {
          private LinkedHashSet<Object> linkedKeys = new LinkedHashSet<>();
  
          @Override
          public Object put(Object key, Object value) {
              linkedKeys.add(key);
              return super.put(key, value);
          }
  
          public int getSize() {
              return linkedKeys.size();
          }
      }
  }
  