com.google.appengine.tools.mapreduce.outputs

Class StringOutput<O,R>

java.lang.Object

com.google.appengine.tools.mapreduce.Output<O,R>

com.google.appengine.tools.mapreduce.outputs.StringOutput<O,R>

Type Parameters:

O - type of values accepted by this output

R - type of result returned by the underlying output

All Implemented Interfaces:

Serializable

public class StringOutput<O,R>
extends Output<O,R>

An output that accepts objects, invokes Object.toString() (or an arbitrary other String-valued Function that is Serializable) on them, adds an optional terminator, encodes the resulting String according to a Charset, and writes the result to an underlying Output. Unmappable characters will be replaced (see CodingErrorAction.REPLACE).

Author:

ohler@google.com (Christian Ohler)

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
StringOutput(com.google.common.base.Function<O,String> fn, String terminator, String charsetName, Output<ByteBuffer,R> sink)
StringOutput(String terminator, Output<ByteBuffer,R> sink)
StringOutput(String terminator, String charsetName, Output<ByteBuffer,R> sink)

Method Summary

Methods

Modifier and Type	Method and Description
List<? extends OutputWriter<O>>	createWriters(int numShards) Returns a list of writers, one for each shard, for this output.
R	finish(Collection<? extends OutputWriter<O>> writers) Returns whatever the underlying Output's finish(java.util.Collection<? extends com.google.appengine.tools.mapreduce.OutputWriter<O>>) method returns.

Methods inherited from class com.google.appengine.tools.mapreduce.Output

getContext, setContext

Methods inherited from class java.lang.Object

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

Constructor Detail

StringOutput

public StringOutput(com.google.common.base.Function<O,String> fn,
            String terminator,
            String charsetName,
            Output<ByteBuffer,R> sink)

StringOutput

public StringOutput(String terminator,
            String charsetName,
            Output<ByteBuffer,R> sink)

StringOutput

public StringOutput(String terminator,
            Output<ByteBuffer,R> sink)

Method Detail

createWriters

public List<? extends OutputWriter<O>> createWriters(int numShards)

Description copied from class: Output

Returns a list of writers, one for each shard, for this output.

Specified by:

createWriters in class Output<O,R>

Parameters:

numShards - The number of shards which should be equal to the number of OutputWriters returned.

finish

public R finish(Collection<? extends OutputWriter<O>> writers)
         throws IOException

Returns whatever the underlying Output's finish(java.util.Collection<? extends com.google.appengine.tools.mapreduce.OutputWriter<O>>) method returns.

Specified by:

finish in class Output<O,R>

Throws:

IOException