org.apache.flink.runtime.io.network.api

Class RecordReader<T extends IOReadableWritable>

java.lang.Object

org.apache.flink.runtime.io.network.api.AbstractRecordReader

org.apache.flink.runtime.io.network.api.AbstractSingleGateRecordReader<T>

org.apache.flink.runtime.io.network.api.RecordReader<T>

Type Parameters:

T - The type of the record that can be read from this record reader.

All Implemented Interfaces:

Reader<T>, ReaderBase

public class RecordReader<T extends IOReadableWritable>
extends AbstractSingleGateRecordReader<T>
implements Reader<T>

A record writer connects an input gate to an application. It allows the application query for incoming records and read them from input gate.

Field Summary

Fields inherited from class org.apache.flink.runtime.io.network.api.AbstractSingleGateRecordReader

inputGate

Constructor Summary

Constructors

Constructor and Description
RecordReader(AbstractInvokable taskBase, Class<T> recordType) Constructs a new record reader and registers a new input gate with the application's environment.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	hasNext() Checks if at least one more record can be read from the associated input gate.
boolean	isInputClosed()
T	next() Reads the current record from the associated input gate.

Methods inherited from class org.apache.flink.runtime.io.network.api.AbstractSingleGateRecordReader

getInputGate, getNumberOfInputChannels, publishEvent, publishEvent

Methods inherited from class org.apache.flink.runtime.io.network.api.AbstractRecordReader

handleEvent, hasReachedEndOfSuperstep, incrementEndOfSuperstepEventAndCheck, setIterative, startNextSuperstep, subscribeToEvent, unsubscribeFromEvent

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.flink.runtime.io.network.api.ReaderBase

hasReachedEndOfSuperstep, publishEvent, publishEvent, setIterative, startNextSuperstep, subscribeToEvent, unsubscribeFromEvent

Constructor Detail

RecordReader

public RecordReader(AbstractInvokable taskBase,
            Class<T> recordType)

Constructs a new record reader and registers a new input gate with the application's environment.

Parameters:

taskBase - The application that instantiated the record reader.

recordType - The class of records that can be read from the record reader.

Method Detail

hasNext

public boolean hasNext()
                throws IOException,
                       InterruptedException

Checks if at least one more record can be read from the associated input gate. This method may block until the associated input gate is able to read the record from one of its input channels.

Specified by:

hasNext in interface Reader<T extends IOReadableWritable>

Returns:

trueit at least one more record can be read from the associated input gate, otherwise false

Throws:

IOException

InterruptedException

next

public T next()
                                  throws IOException,
                                         InterruptedException

Reads the current record from the associated input gate.

Specified by:

next in interface Reader<T extends IOReadableWritable>

Returns:

the current record from the associated input gate.

Throws:

IOException - thrown if any error occurs while reading the record from the input gate

InterruptedException

isInputClosed

public boolean isInputClosed()

Specified by:

isInputClosed in interface ReaderBase