Package org.hobbit.core.rabbit

Class RabbitRpcClient

java.lang.Object

org.hobbit.core.rabbit.RabbitRpcClient

All Implemented Interfaces:

Closeable, AutoCloseable

public class RabbitRpcClient
extends Object
implements Closeable

This class implements a thread safe client that can process several RPC calls in parallel.

Author:

Michael Röder (roeder@informatik.uni-leipzig.de)

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	RabbitRpcClient.RabbitRpcClientConsumer	Internal implementation of a Consumer that receives messages on the reply queue and calls processResponseForRequest(String, byte[]) of its RabbitRpcClient.RabbitRpcClientConsumer.client.
protected static class	RabbitRpcClient.RabbitRpcRequest	Simple extension of the AbstractFuture class that waits for the response which is set by the RabbitRpcClient.RabbitRpcRequest.setResponse(byte[] response).

Field Summary

Fields

Modifier and Type	Field	Description
private Map<String,RabbitRpcClient.RabbitRpcRequest>	currentRequests	Mapping of correlation Ids to their RabbitRpcClient.RabbitRpcRequest instances.
private static final long	DEFAULT_MAX_WAITING_TIME	The default maximum amount of time in millisecond the client is waiting for a response = 600000Lms.
private static final org.slf4j.Logger	LOGGER
private long	maxWaitingTime	The maximum amount of time in millisecond the client is waiting for a response.
private Semaphore	requestMapMutex	Mutex for managing access to the currentRequests object.
private RabbitQueue	requestQueue	Queue used for the request.
private RabbitQueue	responseQueue	Queue used for the responses.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	RabbitRpcClient()	Constructor.

Method Summary

Modifier and Type	Method	Description
void	close()
static RabbitRpcClient	create(com.rabbitmq.client.Connection connection, String requestQueueName)	Creates a StorageServiceClient using the given RabbitMQ Connection.
long	getMaxWaitingTime()
protected void	init(com.rabbitmq.client.Connection connection, String requestQueueName)	Initializes the client by declaring a request queue using the given connection and queue name as well as a second queue and a consumer for retrieving responses.
protected void	processResponseForRequest(String corrId, byte[] body)	Processes the response with the given correlation Id and byte array by searching for a matching request and setting the response if it could be found.
byte[]	request(byte[] data)	Sends the request, i.e., the given data, and blocks until the response is received.
void	setMaxWaitingTime(long maxWaitingTime)	Sets the maximum amount of time the client is waiting for a response.

Methods inherited from class java.lang.Object

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

Field Details

LOGGER

private static final org.slf4j.Logger LOGGER

DEFAULT_MAX_WAITING_TIME

private static final long DEFAULT_MAX_WAITING_TIME

The default maximum amount of time in millisecond the client is waiting for a response = 600000Lms.

See Also:

• Constant Field Values

requestQueue

private RabbitQueue requestQueue

Queue used for the request.

responseQueue

private RabbitQueue responseQueue

Queue used for the responses.

requestMapMutex

private Semaphore requestMapMutex

Mutex for managing access to the currentRequests object.

currentRequests

private Map<String,RabbitRpcClient.RabbitRpcRequest> currentRequests

Mapping of correlation Ids to their RabbitRpcClient.RabbitRpcRequest instances.

maxWaitingTime

private long maxWaitingTime

The maximum amount of time in millisecond the client is waiting for a response. The default value is defined by DEFAULT_MAX_WAITING_TIME.

Constructor Details

RabbitRpcClient

protected RabbitRpcClient()

Constructor.

Method Details

create

public static RabbitRpcClient create(com.rabbitmq.client.Connection connection,
 String requestQueueName)
                              throws IOException

Creates a StorageServiceClient using the given RabbitMQ Connection.

Parameters:

connection - RabbitMQ connection used for the communication

requestQueueName - name of the queue to which the requests should be sent

Returns:

a StorageServiceClient instance

Throws:

IOException - if a problem occurs during the creation of the queues or the consumer.

init

protected void init(com.rabbitmq.client.Connection connection,
 String requestQueueName)
             throws IOException

Initializes the client by declaring a request queue using the given connection and queue name as well as a second queue and a consumer for retrieving responses.

Parameters:

connection - the RabbitMQ connection that is used for creating queues

requestQueueName - the name of the queue

Throws:

IOException - if a communication problem during the creation of the channel, the queue or the internal consumer occurs

request

public byte[] request(byte[] data)

Sends the request, i.e., the given data, and blocks until the response is received.

Parameters:

data - the data of the request

Returns:

the response or null if an error occurs.

processResponseForRequest

protected void processResponseForRequest(String corrId,
 byte[] body)

Processes the response with the given correlation Id and byte array by searching for a matching request and setting the response if it could be found. If there is no request with the same correlation Id, nothing is done.

Parameters:

corrId - correlation Id of the response

body - data of the response

getMaxWaitingTime

public long getMaxWaitingTime()

setMaxWaitingTime

public void setMaxWaitingTime(long maxWaitingTime)

Sets the maximum amount of time the client is waiting for a response.

Parameters:

maxWaitingTime - the maximum waiting time in milliseconds

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException