com.asakusafw.windgate.hadoopfs.temporary

Class FileSystemModelInputProvider<T>

java.lang.Object

com.asakusafw.windgate.hadoopfs.temporary.FileSystemModelInputProvider<T>

Type Parameters:

T - target data model class

All Implemented Interfaces:

ModelInputProvider<T>, Closeable, AutoCloseable

public class FileSystemModelInputProvider<T>
extends Object
implements ModelInputProvider<T>

An implementation of ModelInputProvider using FileSystem.

Since:

0.2.5

Constructor Summary

Constructors

Constructor and Description
FileSystemModelInputProvider(org.apache.hadoop.conf.Configuration configuration, org.apache.hadoop.fs.FileSystem fileSystem, Iterable<org.apache.hadoop.fs.Path> paths, Class<T> dataModelClass) Creates a new instance.

Method Summary

Modifier and Type	Method and Description
void	close()
boolean	next() Returns true iff the next temporary file exists, and then the ModelInputProvider.open() method returns it.
ModelInput<T>	open() Opens the current temporary file prepared by the ModelInputProvider.next() method.

Methods inherited from class java.lang.Object

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

Constructor Detail

FileSystemModelInputProvider

public FileSystemModelInputProvider(org.apache.hadoop.conf.Configuration configuration,
                                    org.apache.hadoop.fs.FileSystem fileSystem,
                                    Iterable<org.apache.hadoop.fs.Path> paths,
                                    Class<T> dataModelClass)
                             throws IOException

Creates a new instance.

Parameters:

configuration - the configuration

fileSystem - target file system

paths - source paths

dataModelClass - target data model class

Throws:

IOException - if failed to resolve paths

IllegalArgumentException - if some parameters were null

Method Detail

next

public boolean next()
             throws IOException

Description copied from interface: ModelInputProvider

Returns true iff the next temporary file exists, and then the ModelInputProvider.open() method returns it.

Specified by:

next in interface ModelInputProvider<T>

Returns:

true if the next data model object exists, otherwise false

Throws:

IOException - if failed to prepare the next data

open

public ModelInput<T> open()
                   throws IOException

Description copied from interface: ModelInputProvider

Opens the current temporary file prepared by the ModelInputProvider.next() method. This operation can perform only once for each temporary file.

Specified by:

open in interface ModelInputProvider<T>

Returns:

the current temporary file contents

Throws:

IOException - if failed to open the file

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException