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.aliyun.odps.mapred.bridge.type;
  
  import java.util.Comparator;
  
  import com.aliyun.odps.OdpsType;
  import com.aliyun.odps.io.BooleanWritable;
  import com.aliyun.odps.io.DatetimeWritable;
  import com.aliyun.odps.io.DoubleWritable;
  import com.aliyun.odps.io.LongWritable;
  import com.aliyun.odps.io.Text;
  
  /**
   * 自然顺序的比较器定义
   */
  public class ComparatorFactory {
  
    @SuppressWarnings("rawtypes")
    public static Comparator getComparator(OdpsType type) {
      switch (type) {
        case STRING:
          return new StringComparator();
        case DOUBLE:
          return new DoubleComparator();
        case BIGINT:
          return new BigintComparator();
        case BOOLEAN:
          return new BooleanComparator();
        case DATETIME:
          return new DatetimeComparator();
        default:
          throw new RuntimeException("Unsupported type in compare:" + type);
      }
    }
  
    /**
     * 比较双方为String类型的比较器
     */
    public static class StringComparator implements Comparator<Text> {
  
      @Override
      public int compare(Text o1, Text o2) {
        if (o1 == null) {
          if (o2 == null) {
            return 0;
          }
          return -1;
        }
        if (o2 == null) {
          return 1;
        }
        return o1.compareTo(o2);
      }
    }
  
    /**
     * 比较双方为Double类型的比较器
     */
    public static class DoubleComparator implements Comparator<DoubleWritable> {
  
      @Override
      public int compare(DoubleWritable o1, DoubleWritable o2) {
        if (o1 == null) {
          if (o2 == null) {
            return 0;
          }
          return -1;
        }
        if (o2 == null) {
          return 1;
        }
        return o1.compareTo(o2);
      }
    }
  
    /**
     * 比较双方为Long类型的比较器
     */
    public static class BigintComparator implements Comparator<LongWritable> {
  
      @Override
      public int compare(LongWritable o1, LongWritable o2) {
        if (o1 == null) {
          if (o2 == null) {
            return 0;
          }
          return -1;
        }
        if (o2 == null) {
          return 1;
        }
        return o1.compareTo(o2);
      }
    }
  
    /**
     * 比较双方为Boolean类型的比较器
     */
    public static class BooleanComparator implements Comparator<BooleanWritable> {
  
      @Override
      public int compare(BooleanWritable o1, BooleanWritable o2) {
        if (o1 == null) {
          if (o2 == null) {
            return 0;
          }
          return -1;
        }
        if (o2 == null) {
          return 1;
        }
        return o1.compareTo(o2);
      }
    }
  
    /**
     * 比较双方为Datetime类型的比较器
     */
    public static class DatetimeComparator implements Comparator<DatetimeWritable> {
  
      @Override
      public int compare(DatetimeWritable o1, DatetimeWritable o2) {
        if (o1 == null) {
          if (o2 == null) {
            return 0;
          }
          return -1;
        }
        if (o2 == null) {
          return 1;
        }
        return o1.compareTo(o2);
      }
    }
  
  }
  