com.remedy.arsys.api
Class ProxyManager

java.lang.Object
  com.remedy.arsys.api.ProxyManager

Direct Known Subclasses:

DefaultProxyManager, PoolingProxyManager

public abstract class ProxyManager

extends java.lang.Object

ProxyManager is a factory class that provides clients with Proxy instances. It is an abstract class that provides the interface used by clients. It is implemented by two concrete subclasses, DefaultProxyManager and PoolingProxyManager. Neither subclass has a public constructor (they are package-scoped) so clients cannot access their services directly. For that, they must call the public static method getProxyManager of ProxyManager.

Proxies represent connections to AR System servers and provide access to their server via the native AR System API. Proxies are optionally pooled by server. A client calling getProxy does not know whether proxies are being pooled or not, so it must return it to the ProxyManager when done by calling releaseProxy and not hold on to a reference to it. If proxies are being pooled this will return the proxy to the pool without terminating its connection. Otherwise, returning it will automatically terminiate its connection and make the proxy available for garbage collection.

The default ProxyManager returned by getProxyManager does not pool connections. Pooling can be initiated by by calling setUseConnectionPooling with argument true. Pooling can be stopped at any time by calling this method with argument false. When pooling is stopped, all connections in the pool will be terminated.

Nested Class Summary

static class

ProxyManager.PoolInfo

Constructor Summary

ProxyManager()

Method Summary

static ProxyManager.PoolInfo[]	getPoolInformation()
abstract Proxy	getProxy(ARServerUser context, boolean usingContextProxy) Get proxy for the AR Server specified by the context.
static ProxyManager	getProxyManager() Get the current ProxyManager instance.
abstract void	releaseProxy(Proxy proxy, ARServerUser context, boolean usingContextProxy) Return a proxy for possible later reuse.
static void	setConnectionLimits(int maxPerServer) Configure limits on proxy pool sizes when connection pooling is used.
static void	setUseConnectionPooling(boolean usePooling) Whether proxies are pooled or not is dynamically configurable.

Methods inherited from class java.lang.Object

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

Constructor Detail

ProxyManager

public ProxyManager()

Method Detail

getProxyManager

public static ProxyManager getProxyManager()

Get the current ProxyManager instance.

setConnectionLimits

public static void setConnectionLimits(int maxPerServer)

Configure limits on proxy pool sizes when connection pooling is used. The maxPerServer and maxTotal parameters decide the number of connections per server and the total number of servers that the program can talk to. So if maxPerServer is 5 and maxTotal is 40, then it means that you can have a max of 8 servers and each can have 5 connections. But because the proxy pool defined in the maxPerServer setting must be filled per server (in our example, 5) before going to the next proxy pool (the next 5), and so on, in order to spread the connections around, you cannot then have 40 servers with 1 connection each.

Parameters:

maxPerServer - Maximum number of proxy connections per server

setUseConnectionPooling

public static void setUseConnectionPooling(boolean usePooling)

Whether proxies are pooled or not is dynamically configurable. This method enables switching between policies. When pooling is turned off, the underlying connection pool is cleared, terminiating each connection. Thereafter, each use of a proxy in a call to the AR System server will result in a new connection being established and being terminated upon completion of the call. A proxy that was taken from a pool and released after the pool has been cleared will have its connection terminated.

getPoolInformation

public static ProxyManager.PoolInfo[] getPoolInformation()

getProxy

public abstract Proxy getProxy(ARServerUser context,
                               boolean usingContextProxy)
                        throws ARException

Get proxy for the AR Server specified by the context. The caller must return the proxy after use by calling returnProxy. The proxy holds one of a limited number of connections to its associated server. The caller must not hold a reference to the proxy after returning it. In nested Java API calls, only the first call requests proxy from the pool and stores that proxy in ServerUser. All the following calls use the proxy from ServerUser.

Throws:

ARException - if proxy not returned

releaseProxy

public abstract void releaseProxy(Proxy proxy,
                                  ARServerUser context,
                                  boolean usingContextProxy)

Return a proxy for possible later reuse. Whether it can be later reused depends on whether the specific ProxyManager being used pools connections or not. The specified context is used to determine which AR System server (and its connection) is associated with this proxy. The caller must not continue to hold a reference to the proxy after returning it to the ProxyManager so that when it expires its connection can be terminated and it can be garbage collected. In nested Java API calls, only the first call should release proxy and set proxy in ServerUser to be null.