## cascading.operation.aggregator
Class MaxValue

    java.lang.Object
      cascading.operation.BaseOperation<ExtremaValueBase.Context>
          cascading.operation.aggregator.ExtremaValueBase
              cascading.operation.aggregator.MaxValue

All Implemented Interfaces:
  DeclaresResults, Aggregator<ExtremaValueBase.Context>, Operation<ExtremaValueBase.Context>, Traceable, Serializable

    public class MaxValue

extends ExtremaValueBase

Class MaxValue is an `Aggregator` that returns the maximum value encountered in the current group.

As opposed to the `Max` class, values are expected to be `Comparable` types vs numeric representations and the `Comparable.compareTo(Object)` result is use for max comparison.

See Also:
  Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class cascading.operation.aggregator.ExtremaValueBase
`ExtremaValueBase.Context`

Field Summary
`static String` `FIELD_NAME` Field FIELD_NAME

Fields inherited from class cascading.operation.aggregator.ExtremaValueBase
`ignoreValues`

Fields inherited from class cascading.operation.BaseOperation
`fieldDeclaration, numArgs, trace`

Fields inherited from interface cascading.operation.Operation
`ANY`

Constructor Summary
`MaxValue()` Constructs a new instance that returns the maximum value encountered in the field name "max".
`MaxValue(Fields fieldDeclaration)` Constructs a new instance that returns the maximum value encountered in the given fieldDeclaration field name.
`MaxValue(Fields fieldDeclaration, Object... ignoreValues)` Constructs a new instance that returns the maximum value encountered in the given fieldDeclaration field name.

Method Summary
`protected boolean` `compare(Comparable lhs, Comparable rhs)` Allows subclasses to provide own comparison method.

Methods inherited from class cascading.operation.aggregator.ExtremaValueBase
`aggregate, complete, equals, getIgnoreValues, getResult, hashCode, prepare, start`

Methods inherited from class cascading.operation.BaseOperation
`cleanup, flush, getFieldDeclaration, getNumArgs, getTrace, isSafe, printOperationInternal, toString, toStringInternal`

Methods inherited from class java.lang.Object
`clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

Methods inherited from interface cascading.operation.Operation
`cleanup, flush, getFieldDeclaration, getNumArgs, isSafe`

Field Detail

### FIELD_NAME

    public static final String FIELD_NAME

  Field FIELD_NAME

  See Also:
    Constant Field Values

Constructor Detail

### MaxValue

    public MaxValue()

  Constructs a new instance that returns the maximum value encountered in the field name "max".

### MaxValue

    @ConstructorProperties(value="fieldDeclaration")
    public MaxValue(Fields fieldDeclaration)

  Constructs a new instance that returns the maximum value encountered in the given fieldDeclaration field name.

  Parameters:
    `fieldDeclaration` - of type Fields

### MaxValue

    @ConstructorProperties(value={"fieldDeclaration","ignoreValues"})
    public MaxValue(Fields fieldDeclaration,
                                               Object... ignoreValues)

  Constructs a new instance that returns the maximum value encountered in the given fieldDeclaration field name. Any argument matching an ignoredValue won't be compared.

  Parameters:
    `fieldDeclaration` - of type Fields
    `ignoreValues` - of type Object...

Method Detail

### compare

    protected boolean compare(Comparable lhs,
                              Comparable rhs)

  Description copied from class: `ExtremaValueBase`
  Allows subclasses to provide own comparison method.

  Specified by:
    `compare` in class `ExtremaValueBase`
  Parameters:
    `lhs` - Comparable type
    `rhs` - Comparable type
  Returns:
    true if the rhs should be retained as the result value

Copyright © 2007-2014 Concurrent, Inc. All Rights Reserved.