org.apache.flink.api.java.functions

类 SelectByMaxFunction<T extends org.apache.flink.api.java.tuple.Tuple>

java.lang.Object

org.apache.flink.api.java.functions.SelectByMaxFunction<T>

类型参数:

T -

所有已实现的接口:

Serializable, org.apache.flink.api.common.functions.Function, org.apache.flink.api.common.functions.ReduceFunction<T>

@Internal
public class SelectByMaxFunction<T extends org.apache.flink.api.java.tuple.Tuple>
extends Object
implements org.apache.flink.api.common.functions.ReduceFunction<T>

Function that enables selection by maximal value of a field.

另请参阅:

序列化表格

构造器概要

构造器

构造器和说明
SelectByMaxFunction(org.apache.flink.api.java.typeutils.TupleTypeInfo<T> type, int... fields) Constructor which is overwriting the default constructor.

方法概要

限定符和类型	方法和说明
T	reduce(T value1, T value2) Reduce implementation, returns bigger tuple or value1 if both tuples are equal.

从类继承的方法 java.lang.Object

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

构造器详细资料

SelectByMaxFunction

public SelectByMaxFunction(org.apache.flink.api.java.typeutils.TupleTypeInfo<T> type,
                           int... fields)

Constructor which is overwriting the default constructor.

参数:

type - Types of tuple whether to check if given fields are key types.

fields - Array of integers which are used as key for comparison. The order of indexes is regarded in the reduce function. First index has highest priority and last index has least priority.

方法详细资料

reduce

public T reduce(T value1,
                T value2)
         throws Exception

Reduce implementation, returns bigger tuple or value1 if both tuples are equal. Comparison highly depends on the order and amount of fields chosen as indices. All given fields (at construction time) are checked in the same order as defined (at construction time). If both tuples are equal in one index, the next index is compared. Or if no next index is available value1 is returned. The tuple which has a bigger value at one index will be returned.

指定者:

reduce 在接口中 org.apache.flink.api.common.functions.ReduceFunction<T extends org.apache.flink.api.java.tuple.Tuple>

抛出:

Exception