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;
  
  import java.io.BufferedInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.URL;
  import java.net.URLConnection;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Enumeration;
  import java.util.List;
  import java.util.Locale;
  import java.util.MissingResourceException;
  import java.util.Properties;
  import java.util.ResourceBundle;
  import java.util.ResourceBundle.Control;
  
  /**
   * @author caikang
   * @date 2017/05/24
   */
  public class I18nResources {
      private static final String XML_LITERAL = "xml";
  
      private static String lang = System.getProperty("pmd.language", "zh");
  
      private static Locale currentLocale;
  
      private static ResourceBundle resourceBundle = changeLanguage(lang);
  
      public static ResourceBundle changeLanguage(String language) {
          Locale locale = Locale.CHINESE.getLanguage().equals(language) ? Locale.CHINESE : Locale.ENGLISH;
          return changeLanguage(locale);
      }
  
      public static ResourceBundle changeLanguage(Locale locale) {
          if (currentLocale != null && currentLocale.equals(locale)) {
              return resourceBundle;
          }
          currentLocale = locale;
          resourceBundle = ResourceBundle.getBundle("messages", locale, new XmlControl());
          return resourceBundle;
      }
  
      public static String getMessage(String key) {
          if (key == null) {
              // 暂时返回空字符串
              return "";
          }
          try {
              return resourceBundle.getString(key).trim();
          } catch (MissingResourceException e) {
              return key;
          }
      }
  
      public static String getMessage(String key, Object... params) {
          String value = getMessage(key);
          if (params == null || params.length == 0) {
              return value;
          }
          return String.format(value, params);
      }
  
      public static String getMessageWithExceptionHandled(String key) {
          if (key == null) {
              // 暂时返回空字符串
              return "";
          }
          try {
              return resourceBundle.getString(key).trim();
          } catch (MissingResourceException e) {
              return key;
          }
      }
  
      public static class XmlResourceBundle extends ResourceBundle {
          private Properties props;
  
          XmlResourceBundle(InputStream stream) throws IOException {
              props = new Properties();
              props.loadFromXML(stream);
          }
  
          @Override
          protected Object handleGetObject(String key) {
              return props.getProperty(key);
          }
  
          @Override
          public Enumeration<String> getKeys() {
              List<String> keys = new ArrayList<>();
              Enumeration<Object> enumeration = props.keys();
              while (enumeration.hasMoreElements()) {
                  keys.add((String)enumeration.nextElement());
              }
              return Collections.enumeration(keys);
          }
      }
  
      public static class XmlControl extends Control {
          @Override
          public List<String> getFormats(String baseName) {
              if (baseName == null) {
                  throw new NullPointerException();
              }
              return Collections.singletonList(XML_LITERAL);
          }
  
          @Override
          public Locale getFallbackLocale(String baseName, Locale locale) {
              return null;
          }
  
          @Override
          public ResourceBundle newBundle(String baseName,
              Locale locale,
              String format,
              ClassLoader loader,
              boolean reload)
              throws IllegalAccessException,
              InstantiationException,
              IOException {
              if (baseName == null || locale == null
                  || format == null || loader == null) {
                  throw new NullPointerException();
              }
              ResourceBundle bundle = null;
              if (XML_LITERAL.equals(format)) {
                  String bundleName = toBundleName(baseName, locale);
                  String resourceName = toResourceName(bundleName, format);
                  InputStream stream;
                  if (reload) {
                      stream = getInputStream(loader, resourceName);
                  } else {
                      stream = loader.getResourceAsStream(resourceName);
                  }
                  if (stream != null) {
                      BufferedInputStream bis = new BufferedInputStream(stream);
                      bundle = new XmlResourceBundle(bis);
                      bis.close();
                  }
              }
              return bundle;
          }
  
          private InputStream getInputStream(ClassLoader loader, String resourceName)
              throws IOException {
              URL url = loader.getResource(resourceName);
              if (url == null) {
                  return null;
              }
              URLConnection connection = url.openConnection();
              if (connection == null) {
                  return null;
              }
              // Disable caches to get fresh data for
              // reloading.
              connection.setUseCaches(false);
              return connection.getInputStream();
          }
      }
  }
  