org.springframework.remoting.httpinvoker
Class HttpInvokerServiceExporter

java.lang.Object
  org.springframework.remoting.support.RemotingSupport
      org.springframework.remoting.support.RemoteExporter
          org.springframework.remoting.support.RemoteInvocationBasedExporter
              org.springframework.remoting.rmi.RemoteInvocationSerializingExporter
                  org.springframework.remoting.httpinvoker.HttpInvokerServiceExporter

All Implemented Interfaces:

Aware, BeanClassLoaderAware, InitializingBean, HttpRequestHandler

public class HttpInvokerServiceExporter
extends RemoteInvocationSerializingExporter
implements HttpRequestHandler

Servlet-API-based HTTP request handler that exports the specified service bean as HTTP invoker service endpoint, accessible via an HTTP invoker proxy.

Note: Spring also provides an alternative version of this exporter, for Sun's JRE 1.6 HTTP server: SimpleHttpInvokerServiceExporter.

Deserializes remote invocation objects and serializes 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 the recommended protocol for Java-to-Java remoting. It is more powerful and more extensible than Hessian and Burlap, at the expense of being tied to Java. Nevertheless, it is as easy to set up as Hessian and Burlap, which is its main advantage compared to RMI.

Since:

1.1

Author:

Juergen Hoeller

See Also:

HttpInvokerClientInterceptor, HttpInvokerProxyFactoryBean, RmiServiceExporter, HessianServiceExporter, BurlapServiceExporter

Field Summary

Fields inherited from class org.springframework.remoting.rmi.RemoteInvocationSerializingExporter

CONTENT_TYPE_SERIALIZED_OBJECT

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

logger

Constructor Summary

HttpInvokerServiceExporter()

Method Summary

protected InputStream	decorateInputStream(HttpServletRequest request, InputStream is) Return the InputStream to use for reading remote invocations, potentially decorating the given original InputStream.
protected OutputStream	decorateOutputStream(HttpServletRequest request, HttpServletResponse response, OutputStream os) Return the OutputStream to use for writing remote invocation results, potentially decorating the given original OutputStream.
void	handleRequest(HttpServletRequest request, HttpServletResponse response) Reads a remote invocation from the request, executes it, and writes the remote invocation result to the response.
protected RemoteInvocation	readRemoteInvocation(HttpServletRequest request) Read a RemoteInvocation from the given HTTP request.
protected RemoteInvocation	readRemoteInvocation(HttpServletRequest request, InputStream is) Deserialize a RemoteInvocation object from the given InputStream.
protected void	writeRemoteInvocationResult(HttpServletRequest request, HttpServletResponse response, RemoteInvocationResult result) Write the given RemoteInvocationResult to the given HTTP response.
protected void	writeRemoteInvocationResult(HttpServletRequest request, HttpServletResponse response, RemoteInvocationResult result, OutputStream os) Serialize the given RemoteInvocation to the given OutputStream.

Methods inherited from class org.springframework.remoting.rmi.RemoteInvocationSerializingExporter

afterPropertiesSet, createObjectInputStream, createObjectOutputStream, doReadRemoteInvocation, doWriteRemoteInvocationResult, getContentType, getProxy, isAcceptProxyClasses, prepare, setAcceptProxyClasses, setContentType

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

getRemoteInvocationExecutor, invoke, invokeAndCreateResult, setRemoteInvocationExecutor

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

checkService, checkServiceInterface, getExporterName, getProxyForService, getService, getServiceInterface, setInterceptors, setRegisterTraceInterceptor, setService, 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

Constructor Detail

HttpInvokerServiceExporter

public HttpInvokerServiceExporter()

Method Detail

handleRequest

public void handleRequest(HttpServletRequest request,
                          HttpServletResponse response)
                   throws ServletException,
                          IOException

Reads a remote invocation from the request, executes it, and writes the remote invocation result to the response.

Specified by:

handleRequest in interface HttpRequestHandler

Parameters:

request - current HTTP request

response - current HTTP response

Throws:

ServletException - in case of general errors

IOException - in case of I/O errors

See Also:

readRemoteInvocation(HttpServletRequest), RemoteInvocationBasedExporter.invokeAndCreateResult(org.springframework.remoting.support.RemoteInvocation, Object), writeRemoteInvocationResult(HttpServletRequest, HttpServletResponse, RemoteInvocationResult)

readRemoteInvocation

protected RemoteInvocation readRemoteInvocation(HttpServletRequest request)
                                         throws IOException,
                                                ClassNotFoundException

Read a RemoteInvocation from the given HTTP request.

Delegates to readRemoteInvocation(javax.servlet.http.HttpServletRequest, java.io.InputStream) with the servlet request's input stream.

Parameters:

request - current HTTP request

Returns:

the RemoteInvocation object

Throws:

IOException - in case of I/O failure

ClassNotFoundException - if thrown by deserialization

readRemoteInvocation

protected RemoteInvocation readRemoteInvocation(HttpServletRequest request,
                                                InputStream is)
                                         throws IOException,
                                                ClassNotFoundException

Deserialize a RemoteInvocation object from the given InputStream.

Gives decorateInputStream(javax.servlet.http.HttpServletRequest, java.io.InputStream) a chance to decorate the stream first (for example, for custom encryption or compression). Creates a CodebaseAwareObjectInputStream and calls RemoteInvocationSerializingExporter.doReadRemoteInvocation(java.io.ObjectInputStream) to actually read the object.

Can be overridden for custom serialization of the invocation.

Parameters:

request - current HTTP request

is - the InputStream to read from

Returns:

the RemoteInvocation object

Throws:

IOException - in case of I/O failure

ClassNotFoundException - if thrown during deserialization

decorateInputStream

protected InputStream decorateInputStream(HttpServletRequest request,
                                          InputStream is)
                                   throws IOException

Return the InputStream to use for reading remote invocations, potentially decorating the given original InputStream.

The default implementation returns the given stream as-is. Can be overridden, for example, for custom encryption or compression.

Parameters:

request - current HTTP request

is - the original InputStream

Returns:

the potentially decorated InputStream

Throws:

IOException - in case of I/O failure

writeRemoteInvocationResult

protected void writeRemoteInvocationResult(HttpServletRequest request,
                                           HttpServletResponse response,
                                           RemoteInvocationResult result)
                                    throws IOException

Write the given RemoteInvocationResult to the given HTTP response.

Parameters:

request - current HTTP request

response - current HTTP response

result - the RemoteInvocationResult object

Throws:

IOException - in case of I/O failure

writeRemoteInvocationResult

protected void writeRemoteInvocationResult(HttpServletRequest request,
                                           HttpServletResponse response,
                                           RemoteInvocationResult result,
                                           OutputStream os)
                                    throws IOException

Serialize the given RemoteInvocation to the given OutputStream.

The default implementation gives decorateOutputStream(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, java.io.OutputStream) a chance to decorate the stream first (for example, for custom encryption or compression). Creates an ObjectOutputStream for the final stream and calls RemoteInvocationSerializingExporter.doWriteRemoteInvocationResult(org.springframework.remoting.support.RemoteInvocationResult, java.io.ObjectOutputStream) to actually write the object.

Can be overridden for custom serialization of the invocation.

Parameters:

request - current HTTP request

response - current HTTP response

result - the RemoteInvocationResult object

os - the OutputStream to write to

Throws:

IOException - in case of I/O failure

See Also:

decorateOutputStream(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, java.io.OutputStream), RemoteInvocationSerializingExporter.doWriteRemoteInvocationResult(org.springframework.remoting.support.RemoteInvocationResult, java.io.ObjectOutputStream)

decorateOutputStream

protected OutputStream decorateOutputStream(HttpServletRequest request,
                                            HttpServletResponse response,
                                            OutputStream os)
                                     throws IOException

Return the OutputStream to use for writing remote invocation results, potentially decorating the given original OutputStream.

The default implementation returns the given stream as-is. Can be overridden, for example, for custom encryption or compression.

Parameters:

request - current HTTP request

response - current HTTP response

os - the original OutputStream

Returns:

the potentially decorated OutputStream

Throws:

IOException - in case of I/O failure