The Spring Framework

org.springframework.remoting.httpinvoker
Class HttpInvokerClientInterceptor

java.lang.Object
  extended by org.springframework.remoting.support.RemoteAccessor
      extended by org.springframework.remoting.support.UrlBasedRemoteAccessor
          extended by org.springframework.remoting.support.RemoteInvocationBasedAccessor
              extended by org.springframework.remoting.httpinvoker.HttpInvokerClientInterceptor
All Implemented Interfaces:
Advice, Interceptor, MethodInterceptor, BeanClassLoaderAware, InitializingBean, HttpInvokerClientConfiguration
Direct Known Subclasses:
HttpInvokerProxyFactoryBean

public class HttpInvokerClientInterceptor
extends RemoteInvocationBasedAccessor
implements MethodInterceptor, HttpInvokerClientConfiguration, BeanClassLoaderAware

Interceptor for accessing an HTTP invoker service. The service URL must be an HTTP URL exposing an HTTP invoker service.

Serializes remote invocation objects and deserializes remote invocation result objects. Uses Java serialization just like RMI, but provides the same ease of setup as Caucho's HTTP-based Hessian and Burlap protocols.

HTTP invoker is a very extensible and customizable protocol. It supports the RemoteInvocationFactory mechanism, like RMI invoker, allowing to include additional invocation attributes (for example, a security context). Furthermore, it allows to customize request execution via the HttpInvokerRequestExecutor strategy.

Can use the JDK's RMIClassLoader to load classes from a given codebase, performing on-demand dynamic code download from a remote location. The codebase can consist of multiple URLs, separated by spaces. Note that RMIClassLoader requires a SecurityManager to be set, analogous to when using dynamic class download with standard RMI! (See the RMI documentation for details.)

Since:
1.1
Author:
Juergen Hoeller
See Also:
UrlBasedRemoteAccessor.setServiceUrl(java.lang.String), setCodebaseUrl(java.lang.String), RemoteInvocationBasedAccessor.setRemoteInvocationFactory(org.springframework.remoting.support.RemoteInvocationFactory), setHttpInvokerRequestExecutor(org.springframework.remoting.httpinvoker.HttpInvokerRequestExecutor), HttpInvokerServiceExporter, HttpInvokerProxyFactoryBean, RMIClassLoader

Field Summary
 
Fields inherited from class org.springframework.remoting.support.RemoteAccessor
logger
 
Constructor Summary
HttpInvokerClientInterceptor()
           
 
Method Summary
 void afterPropertiesSet()
          Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).
protected  RemoteAccessException convertHttpInvokerAccessException(Throwable ex)
          Convert the given HTTP invoker access exception to an appropriate Spring RemoteAccessException.
protected  RemoteInvocationResult executeRequest(RemoteInvocation invocation)
          Execute the given remote invocation via the HttpInvokerRequestExecutor.
protected  ClassLoader getBeanClassLoader()
          Return the ClassLoader that this accessor operates in, to be used for deserializing and for generating proxies.
 String getCodebaseUrl()
          Return the codebase URL to download classes from if not found locally.
 HttpInvokerRequestExecutor getHttpInvokerRequestExecutor()
          Return the HttpInvokerRequestExecutor used by this remote accessor.
 Object invoke(MethodInvocation methodInvocation)
           
 void setBeanClassLoader(ClassLoader classLoader)
          Callback that supplies the bean class loader to a bean instance.
 void setCodebaseUrl(String codebaseUrl)
          Set the codebase URL to download classes from if not found locally.
 void setHttpInvokerRequestExecutor(HttpInvokerRequestExecutor httpInvokerRequestExecutor)
          Set the HttpInvokerRequestExecutor implementation to use for executing remote invocations.
 
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 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface org.springframework.remoting.httpinvoker.HttpInvokerClientConfiguration
getServiceUrl
 

Constructor Detail

HttpInvokerClientInterceptor

public HttpInvokerClientInterceptor()
Method Detail

setCodebaseUrl

public void setCodebaseUrl(String codebaseUrl)
Set the codebase URL to download classes from if not found locally. Can consists of multiple URLs, separated by spaces.

Follows RMI's codebase conventions for dynamic class download. In contrast to RMI, where the server determines the URL for class download (via the "java.rmi.server.codebase" system property), it's the client that determines the codebase URL here. The server will usually be the same as for the service URL, just pointing to a different path there.

See Also:
UrlBasedRemoteAccessor.setServiceUrl(java.lang.String), CodebaseAwareObjectInputStream, RMIClassLoader

getCodebaseUrl

public String getCodebaseUrl()
Return the codebase URL to download classes from if not found locally.

Specified by:
getCodebaseUrl in interface HttpInvokerClientConfiguration
Returns:
the codebase URL, or null if none
See Also:
RMIClassLoader

setHttpInvokerRequestExecutor

public void setHttpInvokerRequestExecutor(HttpInvokerRequestExecutor httpInvokerRequestExecutor)
Set the HttpInvokerRequestExecutor implementation to use for executing remote invocations.

Default is SimpleHttpInvokerRequestExecutor. Alternatively, consider using CommonsHttpInvokerRequestExecutor for more sophisticated needs.

See Also:
SimpleHttpInvokerRequestExecutor, CommonsHttpInvokerRequestExecutor

getHttpInvokerRequestExecutor

public HttpInvokerRequestExecutor getHttpInvokerRequestExecutor()
Return the HttpInvokerRequestExecutor used by this remote accessor.

Creates a default SimpleHttpInvokerRequestExecutor if no executor has been initialized already.


setBeanClassLoader

public void setBeanClassLoader(ClassLoader classLoader)
Description copied from interface: BeanClassLoaderAware
Callback that supplies the bean class loader to a bean instance.

Invoked after the population of normal bean properties but before an initialization callback such as InitializingBean's InitializingBean.afterPropertiesSet() method or a custom init-method.

Specified by:
setBeanClassLoader in interface BeanClassLoaderAware
Parameters:
classLoader - the owning class loader; may be null in which case a default ClassLoader must be used, for example the ClassLoader obtained via ClassUtils.getDefaultClassLoader()

getBeanClassLoader

protected final ClassLoader getBeanClassLoader()
Return the ClassLoader that this accessor operates in, to be used for deserializing and for generating proxies.


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

invoke

public Object invoke(MethodInvocation methodInvocation)
              throws Throwable
Specified by:
invoke in interface MethodInterceptor
Throws:
Throwable

executeRequest

protected RemoteInvocationResult executeRequest(RemoteInvocation invocation)
                                         throws Exception
Execute the given remote invocation via the HttpInvokerRequestExecutor.

Can be overridden in subclasses to pass a different configuration object to the executor. Alternatively, add further configuration properties in a subclass of this accessor: By default, the accessor passed itself as configuration object to the executor.

Parameters:
invocation - the RemoteInvocation to execute
Returns:
the RemoteInvocationResult object
Throws:
IOException - if thrown by I/O operations
ClassNotFoundException - if thrown during deserialization
Exception - in case of general errors
See Also:
getHttpInvokerRequestExecutor(), HttpInvokerClientConfiguration

convertHttpInvokerAccessException

protected RemoteAccessException convertHttpInvokerAccessException(Throwable ex)
Convert the given HTTP invoker access exception to an appropriate Spring RemoteAccessException.

Parameters:
ex - the exception to convert
Returns:
the RemoteAccessException to throw

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