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 org.apache.hadoop.io.LongWritable;
  import org.apache.hadoop.io.Text;
  import org.apache.hadoop.io.Writable;
  import storm.trident.tuple.TridentTuple;
  
  /**
   * Basic <code>SequenceFormat</code> implementation that uses
   * <code>LongWritable</code> for keys and <code>Text</code> for values.
   *
   */
  public class DefaultSequenceFormat implements SequenceFormat {
      private transient LongWritable key;
      private transient Text value;
  
      private String keyField;
      private String valueField;
  
      public DefaultSequenceFormat(String keyField, String valueField){
          this.keyField = keyField;
          this.valueField = valueField;
      }
  
  
  
      @Override
      public Class keyClass() {
          return LongWritable.class;
      }
  
      @Override
      public Class valueClass() {
          return Text.class;
      }
  
      @Override
      public Writable key(TridentTuple tuple) {
          if(this.key == null){
              this.key  = new LongWritable();
          }
          this.key.set(tuple.getLongByField(this.keyField));
          return this.key;
      }
  
      @Override
      public Writable value(TridentTuple tuple) {
          if(this.value == null){
              this.value = new Text();
          }
          this.value.set(tuple.getStringByField(this.valueField));
          return this.value;
      }
  }
  