org.restlet.ext.jetty

Class HttpClientHelper

java.lang.Object

org.restlet.engine.Helper

org.restlet.engine.RestletHelper<T>

org.restlet.engine.connector.ConnectorHelper<Client>

org.restlet.engine.connector.ClientHelper

org.restlet.engine.adapter.HttpClientHelper

org.restlet.ext.jetty.HttpClientHelper

public class HttpClientHelper
extends HttpClientHelper

HTTP client connector using the Jetty project. Here is the list of parameters that are supported. They should be set in the Client's context before it is started:

Parameter name	Value type	Default value	Description
addressResolutionTimeout	long	15000	The timeout in milliseconds for the DNS resolution of host addresses
bindAddress	String	null	The address to bind socket channels to. You must set both this and bindPort
bindPort	int	null	The address to bind socket channels to. You must set both this and bindAddress
connectTimeout	long	15000	The max time in milliseconds a connection can take to connect to destinations
dispatchIo	boolean	true	Whether to dispatch I/O operations from the selector thread to a different thread
followRedirects	boolean	true	Whether to follow HTTP redirects
idleTimeout	long	60000	The max time in milliseconds a connection can be idle (that is, without traffic of bytes in either direction)
maxConnectionsPerDestination	int	10	Sets the max number of connections to open to each destination
maxRedirects	int	8	The max number of HTTP redirects that are followed
maxRequestsQueuedPerDestination	int	1024	Sets the max number of requests that may be queued to a destination
requestBufferSize	int	4096	The size in bytes of the buffer used to write requests
responseBufferSize	int	16384	The size in bytes of the buffer used to read responses
stopTimeout	long	60000	Stop timeout in milliseconds; the maximum time allowed for the service to shutdown
strictEventOrdering	boolean	false	Whether request events must be strictly ordered
tcpNoDelay	boolean	true	Whether TCP_NODELAY is enabled
userAgentField	String	null	The "User-Agent" HTTP header string; when null, uses the Jetty default
sslContextFactory	String	org.restlet.ext.ssl.DefaultSslContextFactory	Let you specify a SslContextFactory qualified class name as a parameter, or an instance as an attribute for a more complete and flexible SSL context setting

For the default SSL parameters see the Javadocs of the DefaultSslContextFactory class.

Author:

Jerome Louvel, Tal Liron

See Also:

Jetty home page

Constructor Summary

Constructors

Constructor and Description
HttpClientHelper(Client client) Constructor.

Method Summary

Modifier and Type	Method and Description
ClientCall	create(Request request) Creates a low-level HTTP client call from a high-level uniform call.
long	getAddressResolutionTimeout() The timeout in milliseconds for the DNS resolution of host addresses.
java.net.SocketAddress	getBindAddress() The address to bind socket channels to.
long	getConnectTimeout() The max time in milliseconds a connection can take to connect to destinations.
java.net.CookieStore	getCookieStore() The cookie store.
java.util.concurrent.Executor	getExecutor() The executor.
org.eclipse.jetty.client.HttpClient	getHttpClient() Returns the wrapped Jetty HTTP client.
long	getIdleTimeout() The max time in milliseconds a connection can be idle (that is, without traffic of bytes in either direction).
int	getMaxConnectionsPerDestination() Sets the max number of connections to open to each destination.
int	getMaxRedirects() The max number of HTTP redirects that are followed.
int	getMaxRequestsQueuedPerDestination() Sets the max number of requests that may be queued to a destination.
int	getRequestBufferSize() The size in bytes of the buffer used to write requests.
int	getResponseBufferSize() The size in bytes of the buffer used to read responses.
org.eclipse.jetty.util.thread.Scheduler	getScheduler() The scheduler.
long	getStopTimeout() Stop timeout in milliseconds.
java.lang.String	getUserAgentField() The "User-Agent" HTTP header string.
boolean	isDispatchIO() Whether to dispatch I/O operations from the selector thread to a different thread.
boolean	isFollowRedirects() Whether to follow HTTP redirects.
boolean	isStrictEventOrdering() Whether request events must be strictly ordered.
boolean	isTcpNoDelay() Whether TCP_NODELAY is enabled.
void	start()
void	stop()

Methods inherited from class org.restlet.engine.adapter.HttpClientHelper

getAdapter, getSocketConnectTimeoutMs, handle, setAdapter

Methods inherited from class org.restlet.engine.connector.ConnectorHelper

getConnectorService, getContext, getProtocols, update

Methods inherited from class org.restlet.engine.RestletHelper

getAttributes, getHelped, getHelpedParameters, getLogger, getMetadataService, setHelped

Methods inherited from class java.lang.Object

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

Constructor Detail

HttpClientHelper

public HttpClientHelper(Client client)

Constructor.

Parameters:

client - The client to help.

Method Detail

create

public ClientCall create(Request request)

Creates a low-level HTTP client call from a high-level uniform call.

Specified by:

create in class HttpClientHelper

Parameters:

request - The high-level request.

Returns:

A low-level HTTP client call.

getAddressResolutionTimeout

public long getAddressResolutionTimeout()

The timeout in milliseconds for the DNS resolution of host addresses. Defaults to 15000.

Returns:

The address resolution timeout.

getBindAddress

public java.net.SocketAddress getBindAddress()

The address to bind socket channels to. Default to null.

Returns:

The bind address or null.

getConnectTimeout

public long getConnectTimeout()

The max time in milliseconds a connection can take to connect to destinations. Defaults to 15000.

Returns:

The connect timeout.

getCookieStore

public java.net.CookieStore getCookieStore()

The cookie store. Defaults to null. When null, creates a new instance of InMemoryCookieStore.

Returns:

The cookie store.

getExecutor

public java.util.concurrent.Executor getExecutor()

The executor. Defaults to null. When null, creates a new instance of QueuedThreadPool.

Returns:

The executor.

getHttpClient

public org.eclipse.jetty.client.HttpClient getHttpClient()

Returns the wrapped Jetty HTTP client.

Returns:

The wrapped Jetty HTTP client.

getIdleTimeout

public long getIdleTimeout()

The max time in milliseconds a connection can be idle (that is, without traffic of bytes in either direction). Defaults to 60000.

Returns:

The idle timeout.

getMaxConnectionsPerDestination

public int getMaxConnectionsPerDestination()

Sets the max number of connections to open to each destination. Defaults to 10.

RFC 2616 suggests that 2 connections should be opened per each destination, but browsers commonly open 6. If this client is used for load testing, it is common to have only one destination (the server to load test), and it is recommended to set this value to a high value (at least as much as the threads present in the executor).

Returns:

The maximum connections per destination.

getMaxRedirects

public int getMaxRedirects()

The max number of HTTP redirects that are followed. Defaults to 8.

Returns:

The maximum redirects.

getMaxRequestsQueuedPerDestination

public int getMaxRequestsQueuedPerDestination()

Sets the max number of requests that may be queued to a destination. Defaults to 1024.

If this client performs a high rate of requests to a destination, and all the connections managed by that destination are busy with other requests, then new requests will be queued up in the destination. This parameter controls how many requests can be queued before starting to reject them. If this client is used for load testing, it is common to have this parameter set to a high value, although this may impact latency (requests sit in the queue for a long time before being sent).

Returns:

The maximum requests queues per destination.

getRequestBufferSize

public int getRequestBufferSize()

The size in bytes of the buffer used to write requests. Defaults to 4096.

Returns:

The request buffer size.

getResponseBufferSize

public int getResponseBufferSize()

The size in bytes of the buffer used to read responses. Defaults to 16384.

Returns:

The response buffer size.

getScheduler

public org.eclipse.jetty.util.thread.Scheduler getScheduler()

The scheduler. Defaults to null. When null, creates a new instance of ScheduledExecutorScheduler.

Returns:

The scheduler.

getStopTimeout

public long getStopTimeout()

Stop timeout in milliseconds. Defaults to 60000.

The maximum time allowed for the service to shutdown.

Returns:

The stop timeout.

getUserAgentField

public java.lang.String getUserAgentField()

The "User-Agent" HTTP header string. When null, uses the Jetty default. Defaults to null.

Returns:

The user agent field or null.

isDispatchIO

public boolean isDispatchIO()

Whether to dispatch I/O operations from the selector thread to a different thread. Defaults to true.

This implementation never blocks on I/O operation, but invokes application callbacks that may take time to execute or block on other I/O. If application callbacks are known to take time or block on I/O, then this should be set to true. If application callbacks are known to be quick and never block on I/O, then this may be set to false.

Returns:

Whether to dispatch I/O.

isFollowRedirects

public boolean isFollowRedirects()

Whether to follow HTTP redirects. Defaults to true.

Returns:

Whether to follow redirects.

isStrictEventOrdering

public boolean isStrictEventOrdering()

Whether request events must be strictly ordered. Defaults to false.

Client listeners may send a second request. If the second request is for the same destination, there is an inherent race condition for the use of the connection: the first request may still be associated with the connection, so the second request cannot use that connection and is forced to open another one.

From the point of view of connection usage, the connection is reusable just before the "complete" event, so it would be possible to reuse that connection from complete listeners; but in this case the second request's events will fire before the "complete" events of the first request.

This setting enforces strict event ordering so that a "begin" event of a second request can never fire before the "complete" event of a first request, but at the expense of an increased usage of connections.

When not enforced, a "begin" event of a second request may happen before the "complete" event of a first request and allow for better usage of connections.

Returns:

Whether request events must be strictly ordered.

isTcpNoDelay

public boolean isTcpNoDelay()

Whether TCP_NODELAY is enabled. Defaults to true.

Returns:

Whether TCP_NODELAY is enabled.

start

public void start()
           throws java.lang.Exception

Overrides:

start in class ConnectorHelper<Client>

Throws:

java.lang.Exception

stop

public void stop()
          throws java.lang.Exception

Overrides:

stop in class ConnectorHelper<Client>

Throws:

java.lang.Exception