content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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.ververica.field.dynamicrules;
  
  import java.util.Iterator;
  import java.util.List;
  
  /** Utilities for dynamic keys extraction by field name. */
  public class KeysExtractor {
  
    /**
     * Extracts and concatenates field values by names.
     *
     * @param keyNames list of field names
     * @param object target for values extraction
     */
    public static String getKey(List<String> keyNames, Object object)
        throws NoSuchFieldException, IllegalAccessException {
      StringBuilder sb = new StringBuilder();
      sb.append("{");
      if (keyNames.size() > 0) {
        Iterator<String> it = keyNames.iterator();
        appendKeyValue(sb, object, it.next());
  
        while (it.hasNext()) {
          sb.append(";");
          appendKeyValue(sb, object, it.next());
        }
      }
      sb.append("}");
      return sb.toString();
    }
  
    private static void appendKeyValue(StringBuilder sb, Object object, String fieldName)
        throws IllegalAccessException, NoSuchFieldException {
      sb.append(fieldName);
      sb.append("=");
      sb.append(FieldsExtractor.getFieldAsString(object, fieldName));
    }
  }
  