org.springframework.remoting.rmi

Class RmiClientInterceptor

java.lang.Object

org.springframework.remoting.support.RemotingSupport

org.springframework.remoting.support.RemoteAccessor

org.springframework.remoting.support.UrlBasedRemoteAccessor

org.springframework.remoting.support.RemoteInvocationBasedAccessor

org.springframework.remoting.rmi.RmiClientInterceptor

All Implemented Interfaces:

Aware, BeanClassLoaderAware, InitializingBean

Direct Known Subclasses:

RmiProxyFactoryBean

public class RmiClientInterceptor
extends RemoteInvocationBasedAccessor

org.aopalliance.intercept.MethodInterceptor for accessing conventional RMI services or RMI invokers. The service URL must be a valid RMI URL (e.g. "rmi://localhost:1099/myservice").

RMI invokers work at the RmiInvocationHandler level, needing only one stub for any service. Service interfaces do not have to extend java.rmi.Remote or throw java.rmi.RemoteException. Spring's unchecked RemoteAccessException will be thrown on remote invocation failure. Of course, in and out parameters have to be serializable.

With conventional RMI services, this invoker is typically used with the RMI service interface. Alternatively, this invoker can also proxy a remote RMI service with a matching non-RMI business interface, i.e. an interface that mirrors the RMI service methods but does not declare RemoteExceptions. In the latter case, RemoteExceptions thrown by the RMI stub will automatically get converted to Spring's unchecked RemoteAccessException.

Since:

29.09.2003

Author:

Juergen Hoeller

See Also:

RmiServiceExporter, RmiProxyFactoryBean, RmiInvocationHandler, RemoteAccessException, RemoteException, Remote

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	RmiClientInterceptor.DummyURLStreamHandler Dummy URLStreamHandler that's just specified to suppress the standard java.net.URL URLStreamHandler lookup, to be able to use the standard URL class for parsing "rmi:..." URLs.

Field Summary

Fields

Modifier and Type	Field and Description
private java.rmi.Remote	cachedStub
private boolean	cacheStub
private boolean	lookupStubOnStartup
private boolean	refreshStubOnConnectFailure
private java.rmi.server.RMIClientSocketFactory	registryClientSocketFactory
private java.lang.Object	stubMonitor

Fields inherited from class org.springframework.remoting.support.RemotingSupport

logger

Constructor Summary

Constructors

Constructor and Description
RmiClientInterceptor()

Method Summary

Modifier and Type	Method and Description
void	afterPropertiesSet() Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).
protected java.lang.Object	doInvoke(MethodInvocation invocation, java.rmi.Remote stub) Perform the given invocation on the given RMI stub.
protected java.lang.Object	doInvoke(MethodInvocation methodInvocation, RmiInvocationHandler invocationHandler) Apply the given AOP method invocation to the given RmiInvocationHandler.
protected java.rmi.Remote	getStub() Return the RMI stub to use.
private java.lang.Object	handleRemoteConnectFailure(MethodInvocation invocation, java.lang.Exception ex) Refresh the stub and retry the remote invocation if necessary.
java.lang.Object	invoke(MethodInvocation invocation) Fetches an RMI stub and delegates to doInvoke.
protected boolean	isConnectFailure(java.rmi.RemoteException ex) Determine whether the given RMI exception indicates a connect failure.
protected java.rmi.Remote	lookupStub() Create the RMI stub, typically by looking it up.
void	prepare() Fetches RMI stub on startup, if necessary.
protected java.lang.Object	refreshAndRetry(MethodInvocation invocation) Refresh the RMI stub and retry the given invocation.
void	setCacheStub(boolean cacheStub) Set whether to cache the RMI stub once it has been located.
void	setLookupStubOnStartup(boolean lookupStubOnStartup) Set whether to look up the RMI stub on startup.
void	setRefreshStubOnConnectFailure(boolean refreshStubOnConnectFailure) Set whether to refresh the RMI stub on connect failure.
void	setRegistryClientSocketFactory(java.rmi.server.RMIClientSocketFactory registryClientSocketFactory) Set a custom RMI client socket factory to use for accessing the RMI registry.

Methods inherited from class org.springframework.remoting.support.RemoteInvocationBasedAccessor

createRemoteInvocation, getRemoteInvocationFactory, recreateRemoteInvocationResult, setRemoteInvocationFactory

Methods inherited from class org.springframework.remoting.support.UrlBasedRemoteAccessor

getServiceUrl, setServiceUrl

Methods inherited from class org.springframework.remoting.support.RemoteAccessor

getServiceInterface, setServiceInterface

Methods inherited from class org.springframework.remoting.support.RemotingSupport

getBeanClassLoader, overrideThreadContextClassLoader, resetThreadContextClassLoader, setBeanClassLoader

Methods inherited from class java.lang.Object

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

Field Detail

lookupStubOnStartup

private boolean lookupStubOnStartup

cacheStub

private boolean cacheStub

refreshStubOnConnectFailure

private boolean refreshStubOnConnectFailure

registryClientSocketFactory

private java.rmi.server.RMIClientSocketFactory registryClientSocketFactory

cachedStub

private java.rmi.Remote cachedStub

stubMonitor

private final java.lang.Object stubMonitor

Constructor Detail

RmiClientInterceptor

public RmiClientInterceptor()

Method Detail

setLookupStubOnStartup

public void setLookupStubOnStartup(boolean lookupStubOnStartup)

Set whether to look up the RMI stub on startup. Default is "true".

Can be turned off to allow for late start of the RMI server. In this case, the RMI stub will be fetched on first access.

See Also:

setCacheStub(boolean)

setCacheStub

public void setCacheStub(boolean cacheStub)

Set whether to cache the RMI stub once it has been located. Default is "true".

Can be turned off to allow for hot restart of the RMI server. In this case, the RMI stub will be fetched for each invocation.

See Also:

setLookupStubOnStartup(boolean)

setRefreshStubOnConnectFailure

public void setRefreshStubOnConnectFailure(boolean refreshStubOnConnectFailure)

Set whether to refresh the RMI stub on connect failure. Default is "false".

Can be turned on to allow for hot restart of the RMI server. If a cached RMI stub throws an RMI exception that indicates a remote connect failure, a fresh proxy will be fetched and the invocation will be retried.

See Also:

ConnectException, ConnectIOException, NoSuchObjectException

setRegistryClientSocketFactory

public void setRegistryClientSocketFactory(java.rmi.server.RMIClientSocketFactory registryClientSocketFactory)

Set a custom RMI client socket factory to use for accessing the RMI registry.

See Also:

RMIClientSocketFactory, LocateRegistry.getRegistry(String, int, RMIClientSocketFactory)

afterPropertiesSet

public void afterPropertiesSet()

Description copied from interface: InitializingBean

Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).

This method allows the bean instance to perform initialization only possible when all bean properties have been set and to throw an exception in the event of misconfiguration.

Specified by:

afterPropertiesSet in interface InitializingBean

Overrides:

afterPropertiesSet in class UrlBasedRemoteAccessor

prepare

public void prepare()
             throws RemoteLookupFailureException

Fetches RMI stub on startup, if necessary.

Throws:

RemoteLookupFailureException - if RMI stub creation failed

See Also:

setLookupStubOnStartup(boolean), lookupStub()

lookupStub

protected java.rmi.Remote lookupStub()
                              throws RemoteLookupFailureException

Create the RMI stub, typically by looking it up.

Called on interceptor initialization if "cacheStub" is "true"; else called for each invocation by getStub().

The default implementation looks up the service URL via java.rmi.Naming. This can be overridden in subclasses.

Returns:

the RMI stub to store in this interceptor

Throws:

RemoteLookupFailureException - if RMI stub creation failed

See Also:

setCacheStub(boolean), Naming.lookup(java.lang.String)

getStub

protected java.rmi.Remote getStub()
                           throws RemoteLookupFailureException

Return the RMI stub to use. Called for each invocation.

The default implementation returns the stub created on initialization, if any. Else, it invokes lookupStub() to get a new stub for each invocation. This can be overridden in subclasses, for example in order to cache a stub for a given amount of time before recreating it, or to test the stub whether it is still alive.

Returns:

the RMI stub to use for an invocation

Throws:

RemoteLookupFailureException - if RMI stub creation failed

See Also:

lookupStub()

invoke

public java.lang.Object invoke(MethodInvocation invocation)
                        throws java.lang.Throwable

Fetches an RMI stub and delegates to doInvoke. If configured to refresh on connect failure, it will call refreshAndRetry(MethodInvocation) on corresponding RMI exceptions.

Throws:

java.lang.Throwable

See Also:

getStub(), doInvoke(MethodInvocation, Remote), refreshAndRetry(MethodInvocation), ConnectException, ConnectIOException, NoSuchObjectException

isConnectFailure

protected boolean isConnectFailure(java.rmi.RemoteException ex)

Determine whether the given RMI exception indicates a connect failure.

The default implementation delegates to RmiClientInterceptorUtils.isConnectFailure(java.rmi.RemoteException).

Parameters:

ex - the RMI exception to check

Returns:

whether the exception should be treated as connect failure

handleRemoteConnectFailure

private java.lang.Object handleRemoteConnectFailure(MethodInvocation invocation,
                                                    java.lang.Exception ex)
                                             throws java.lang.Throwable

Refresh the stub and retry the remote invocation if necessary.

If not configured to refresh on connect failure, this method simply rethrows the original exception.

Parameters:

invocation - the invocation that failed

ex - the exception raised on remote invocation

Returns:

the result value of the new invocation, if succeeded

Throws:

java.lang.Throwable - an exception raised by the new invocation, if it failed as well

See Also:

setRefreshStubOnConnectFailure(boolean), doInvoke(MethodInvocation, java.rmi.Remote)

refreshAndRetry

protected java.lang.Object refreshAndRetry(MethodInvocation invocation)
                                    throws java.lang.Throwable

Refresh the RMI stub and retry the given invocation. Called by invoke on connect failure.

Parameters:

invocation - the AOP method invocation

Returns:

the invocation result, if any

Throws:

java.lang.Throwable - in case of invocation failure

See Also:

invoke(MethodInvocation)

doInvoke

protected java.lang.Object doInvoke(MethodInvocation invocation,
                                    java.rmi.Remote stub)
                             throws java.lang.Throwable

Perform the given invocation on the given RMI stub.

Parameters:

invocation - the AOP method invocation

stub - the RMI stub to invoke

Returns:

the invocation result, if any

Throws:

java.lang.Throwable - in case of invocation failure

doInvoke

protected java.lang.Object doInvoke(MethodInvocation methodInvocation,
                                    RmiInvocationHandler invocationHandler)
                             throws java.rmi.RemoteException,
                                    java.lang.NoSuchMethodException,
                                    java.lang.IllegalAccessException,
                                    java.lang.reflect.InvocationTargetException

Apply the given AOP method invocation to the given RmiInvocationHandler.

The default implementation delegates to RemoteInvocationBasedAccessor.createRemoteInvocation(MethodInvocation).

Parameters:

methodInvocation - the current AOP method invocation

invocationHandler - the RmiInvocationHandler to apply the invocation to

Returns:

the invocation result

Throws:

java.rmi.RemoteException - in case of communication errors

java.lang.NoSuchMethodException - if the method name could not be resolved

java.lang.IllegalAccessException - if the method could not be accessed

java.lang.reflect.InvocationTargetException - if the method invocation resulted in an exception

See Also:

RemoteInvocation