com.aliyun.odps.mapred.local.utils

Class LocalColumnBasedRecordComparator

java.lang.Object

com.aliyun.odps.mapred.bridge.type.NaturalRecordComparator

com.aliyun.odps.mapred.local.utils.LocalColumnBasedRecordComparator

All Implemented Interfaces:

Comparator<Object[]>

public class LocalColumnBasedRecordComparator
extends NaturalRecordComparator

可以指定排序列的RecordComparator。排序策略是自然序。

Constructor Summary

Constructors

Constructor and Description
LocalColumnBasedRecordComparator(int[] selIdxs, Column[] schema, JobConf.SortOrder[] sortOrders) ColumnBasedRecordComparator的构造方法，指定排序列的下标索引。例如指定排序列的下标索引为0，3，则比较时先用第0列比较， 第0列相同时使用第3列比较。
LocalColumnBasedRecordComparator(String[] selCols, Column[] schema, JobConf.SortOrder[] sortOrders) ColumnBasedRecordComparator的构造方法，指定排序列的列名。例如指定排序列的下标索引为“word”，“count”， 则比较时先用word列比较， word列相同时使用count列比较。

Method Summary

Modifier and Type	Method and Description
int	compare(Object[] l, Object[] r)

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Comparator

comparing, comparing, comparingDouble, comparingInt, comparingLong, equals, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Constructor Detail

LocalColumnBasedRecordComparator

public LocalColumnBasedRecordComparator(int[] selIdxs,
                                        Column[] schema,
                                        JobConf.SortOrder[] sortOrders)

ColumnBasedRecordComparator的构造方法，指定排序列的下标索引。例如指定排序列的下标索引为0，3，则比较时先用第0列比较， 第0列相同时使用第3列比较。

Parameters:

selIdxs - 排序列的下标索引

schema - 整个Record的行属性

LocalColumnBasedRecordComparator

public LocalColumnBasedRecordComparator(String[] selCols,
                                        Column[] schema,
                                        JobConf.SortOrder[] sortOrders)

ColumnBasedRecordComparator的构造方法，指定排序列的列名。例如指定排序列的下标索引为“word”，“count”， 则比较时先用word列比较， word列相同时使用count列比较。

Parameters:

selCols -

schema -

Method Detail

compare

public int compare(Object[] l,
                   Object[] r)

Specified by:

compare in interface Comparator<Object[]>

Overrides:

compare in class NaturalRecordComparator