## cascading.operation
Class Identity

    java.lang.Object
      cascading.operation.BaseOperation<cascading.operation.Identity.Functor>
          cascading.operation.Identity

All Implemented Interfaces:
  DeclaresResults, Function<cascading.operation.Identity.Functor>, Operation<cascading.operation.Identity.Functor>, Traceable, Serializable

    public class Identity

extends BaseOperation<cascading.operation.Identity.Functor>
implements Function<cascading.operation.Identity.Functor>

The Identity function simply passes incoming arguments back out again. Optionally argument fields can be renamed, and/or coerced into specific types.

During coercion, if the given type is a primitive (`long`), and the tuple value is null, `0` is returned. If the type is an Object (`java.lang.Long`), and the tuple value is `null`, `null` is returned.

See Also:
  Serialized Form

Field Summary

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

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

Constructor Summary
`Identity()` Constructor Identity creates a new Identity instance that will pass the argument values to its output.
`Identity(Class... types)` Constructor Identity creates a new Identity instance that will coerce the values to the give types.
`Identity(Fields fieldDeclaration)` Constructor Identity creates a new Identity instance that will rename the argument fields to the given fieldDeclaration.
`Identity(Fields fieldDeclaration, Class... types)` Constructor Identity creates a new Identity instance that will rename the argument fields to the given fieldDeclaration, and coerce the values to the give types.

Method Summary
`boolean` `equals(Object object)`
`Type[]` `getTypes()`
`int` `hashCode()`
`void` `operate(FlowProcess flowProcess, FunctionCall<cascading.operation.Identity.Functor> functionCall)` Method operate provides the implementation of this Function.
`void` `prepare(FlowProcess flowProcess, OperationCall<cascading.operation.Identity.Functor> operationCall)` Method prepare does nothing, and may safely be overridden.

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`

Constructor Detail

### Identity

    public Identity()

  Constructor Identity creates a new Identity instance that will pass the argument values to its output. Use this constructor for a simple copy Pipe.

### Identity

    @ConstructorProperties(value="types")
    public Identity(Class... types)

  Constructor Identity creates a new Identity instance that will coerce the values to the give types.

  Parameters:
    `types` - of type Class...

### Identity

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

  Constructor Identity creates a new Identity instance that will rename the argument fields to the given fieldDeclaration.

  Parameters:
    `fieldDeclaration` - of type Fields

### Identity

    @ConstructorProperties(value={"fieldDeclaration","types"})
    public Identity(Fields fieldDeclaration,
                                               Class... types)

  Constructor Identity creates a new Identity instance that will rename the argument fields to the given fieldDeclaration, and coerce the values to the give types.

  Parameters:
    `fieldDeclaration` - of type Fields
    `types` - of type Class...

Method Detail

### getTypes

    public Type[] getTypes()

### prepare

    public void prepare(FlowProcess flowProcess,
                        OperationCall<cascading.operation.Identity.Functor> operationCall)

  Description copied from class: `BaseOperation`
  Method prepare does nothing, and may safely be overridden.

  Specified by:
    `prepare` in interface `Operation<cascading.operation.Identity.Functor>`
  Overrides:
    `prepare` in class `BaseOperation<cascading.operation.Identity.Functor>`

### operate

    public void operate(FlowProcess flowProcess,
                        FunctionCall<cascading.operation.Identity.Functor> functionCall)

  Description copied from interface: `Function`
  Method operate provides the implementation of this Function.

  Specified by:
    `operate` in interface `Function<cascading.operation.Identity.Functor>`
  Parameters:
    `flowProcess` - of type FlowProcess
    `functionCall` - of type FunctionCall

### equals

    public boolean equals(Object object)

  Overrides:
    `equals` in class `BaseOperation<cascading.operation.Identity.Functor>`

### hashCode

    public int hashCode()

  Overrides:
    `hashCode` in class `BaseOperation<cascading.operation.Identity.Functor>`

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