/**
    *    Copyright 2009-2015 the original author or authors.
    *
    *    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 org.apache.ibatis.parsing;
  
  import java.util.Properties;
  
  /**
   * @author Clinton Begin
   */
  public class PropertyParser {
  
    private PropertyParser() {
      // Prevent Instantiation
    }
  
    public static String parse(String string, Properties variables) {
      VariableTokenHandler handler = new VariableTokenHandler(variables);
      GenericTokenParser parser = new GenericTokenParser("${", "}", handler);
      return parser.parse(string);
    }
  
    private static class VariableTokenHandler implements TokenHandler {
      private Properties variables;
  
      public VariableTokenHandler(Properties variables) {
        this.variables = variables;
      }
  
      @Override
      public String handleToken(String content) {
        if (variables != null && variables.containsKey(content)) {
          return variables.getProperty(content);
        }
        return "${" + content + "}";
      }
    }
  }