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.alibaba.jstorm.hdfs.trident.format;
  
  
  import backtype.storm.tuple.Fields;
  import storm.trident.tuple.TridentTuple;
  
  /**
   * RecordFormat implementation that uses field and record delimiters.
   * By default uses a comma (",") as the field delimiter and a
   * newline ("\n") as the record delimiter.
   *
   *
   */
  public class DelimitedRecordFormat implements RecordFormat {
      public static final String DEFAULT_FIELD_DELIMITER = ",";
      public static final String DEFAULT_RECORD_DELIMITER = "\n";
      private String fieldDelimiter = DEFAULT_FIELD_DELIMITER;
      private String recordDelimiter = DEFAULT_RECORD_DELIMITER;
      private Fields fields = null;
  
      /**
       * Only output the specified fields.
       *
       * @param fields
       * @return
       */
      public DelimitedRecordFormat withFields(Fields fields){
          this.fields = fields;
          return this;
      }
  
      /**
       * Overrides the default field delimiter.
       *
       * @param delimiter
       * @return
       */
      public DelimitedRecordFormat withFieldDelimiter(String delimiter){
          this.fieldDelimiter = delimiter;
          return this;
      }
  
      /**
       * Overrides the default record delimiter.
       *
       * @param delimiter
       * @return
       */
      public DelimitedRecordFormat withRecordDelimiter(String delimiter){
          this.recordDelimiter = delimiter;
          return this;
      }
  
      @Override
      public byte[] format(TridentTuple tuple) {
          StringBuilder sb = new StringBuilder();
          int size = this.fields.size();
          for(int i = 0; i < size; i++){
              sb.append(tuple.getValueByField(fields.get(i)));
              if(i != size - 1){
                  sb.append(this.fieldDelimiter);
              }
          }
          sb.append(this.recordDelimiter);
          return sb.toString().getBytes();
      }
  }
  