com.amazonaws.handlers

Class StackedRequestHandler

java.lang.Object

com.amazonaws.handlers.StackedRequestHandler

All Implemented Interfaces:

IRequestHandler2

@ThreadSafe
public class StackedRequestHandler
extends Object
implements IRequestHandler2

Composite RequestHandler2 to execute a chain of RequestHandler2 implementations in stack order. That is if you have request handlers R1, R2, R3 the order of execution is as follows

    
    
 R1.beforeMarshalling   
 R2.beforeMarshalling   
 R3.beforeMarshalling   
    
 R1.beforeRequest   
 R2.beforeRequest   
 R3.beforeRequest   
    
 R3.beforeUnmarshalling
 R2.beforeUnmarshalling
 R1.beforeUnmarshalling
 
 R3.after(Response|Error)   
 R2.after(Response|Error)   
 R1.after(Response|Error)   
 
 

Constructor Summary

Constructors

Constructor and Description
StackedRequestHandler(List<RequestHandler2> requestHandlers)
StackedRequestHandler(RequestHandler2... requestHandlers)

Method Summary

Modifier and Type	Method and Description
void	afterError(Request<?> request, Response<?> response, Exception e) Runs any additional processing logic on a request after it has failed.
void	afterResponse(Request<?> request, Response<?> response) Runs any additional processing logic on the specified request (after is has been executed by the client runtime).
AmazonWebServiceRequest	beforeExecution(AmazonWebServiceRequest origRequest) Runs any additional processing logic on the specified request object as soon as the request is provided to the service client.
AmazonWebServiceRequest	beforeMarshalling(AmazonWebServiceRequest origRequest) Runs any additional processing logic on the specified request object before it is marshaled into an HTTP request.
void	beforeRequest(Request<?> request) Runs any additional processing logic on the specified request (before it is executed by the client runtime).
HttpResponse	beforeUnmarshalling(Request<?> request, HttpResponse origHttpResponse) Runs any additional processing logic on the specified response before it's unmarshalled.

Methods inherited from class java.lang.Object

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

Constructor Detail

StackedRequestHandler

public StackedRequestHandler(RequestHandler2... requestHandlers)

StackedRequestHandler

public StackedRequestHandler(List<RequestHandler2> requestHandlers)

Method Detail

beforeExecution

public AmazonWebServiceRequest beforeExecution(AmazonWebServiceRequest origRequest)

Description copied from interface: IRequestHandler2

Runs any additional processing logic on the specified request object as soon as the request is provided to the service client.

This request handler is excluded from the client execution time metrics and is run on the application's thread, even for asynchronous requests.

Warning: Modifications to this message will leak out to the user, who might reuse the request object without realizing that it was modified as part of sending it the first time. For this reason, we recommend that you only modify the request in the IRequestHandler2.beforeRequest(Request) method. If you require data that is not available in that method, you should create a AmazonWebServiceRequest.clone() of the request (which performs a deep copy of the handler context map), add any context data you require in the IRequestHandler2.beforeRequest(Request) method using AmazonWebServiceRequest.addHandlerContext(HandlerContextKey, Object), and return your cloned message from this method. You can then extract that data for use in the request using HandlerContextAware.getHandlerContext(HandlerContextKey).

Specified by:

beforeExecution in interface IRequestHandler2

Parameters:

origRequest - the request passed in by the user

Returns:

the (possibly different) request to execute

beforeMarshalling

public AmazonWebServiceRequest beforeMarshalling(AmazonWebServiceRequest origRequest)

Description copied from interface: IRequestHandler2

Runs any additional processing logic on the specified request object before it is marshaled into an HTTP request.

Warning: Modifications to this message will leak out to the user, who might reuse the request object without realizing that it was modified as part of sending it the first time. For this reason, we recommend that you only modify the request in the IRequestHandler2.beforeRequest(Request) method. If you require data that is not available in that method, you should create a AmazonWebServiceRequest.clone() of the request (which performs a deep copy of the handler context map), add any context data you require in the IRequestHandler2.beforeRequest(Request) method using AmazonWebServiceRequest.addHandlerContext(HandlerContextKey, Object), and return your cloned message from this method. You can then extract that data for use in the request using HandlerContextAware.getHandlerContext(HandlerContextKey).

Specified by:

beforeMarshalling in interface IRequestHandler2

Parameters:

origRequest - the request passed in by the user

Returns:

the (possibly different) request to marshal

beforeRequest

public void beforeRequest(Request<?> request)

Description copied from interface: IRequestHandler2

Runs any additional processing logic on the specified request (before it is executed by the client runtime).

Specified by:

beforeRequest in interface IRequestHandler2

Parameters:

request - The low level request being processed.

beforeUnmarshalling

public HttpResponse beforeUnmarshalling(Request<?> request,
                                        HttpResponse origHttpResponse)

Description copied from interface: IRequestHandler2

Runs any additional processing logic on the specified response before it's unmarshalled. This callback is only invoked on successful responses that will be unmarshalled into an appropriate modeled class and not for unsuccessful responses that will be unmarshalled into a subclass of AmazonServiceException

Specified by:

beforeUnmarshalling in interface IRequestHandler2

Parameters:

request - The low level request being processed.

origHttpResponse - The Raw HTTP response before being unmarshalled

Returns:

HttpResponse to replace the actual response. May be a mutated version of the original or a completely new HttpResponse object

afterResponse

public void afterResponse(Request<?> request,
                          Response<?> response)

Description copied from interface: IRequestHandler2

Runs any additional processing logic on the specified request (after is has been executed by the client runtime).

Specified by:

afterResponse in interface IRequestHandler2

Parameters:

request - The low level request being processed.

response - The response generated from the specified request.

afterError

public void afterError(Request<?> request,
                       Response<?> response,
                       Exception e)

Description copied from interface: IRequestHandler2

Runs any additional processing logic on a request after it has failed.

Specified by:

afterError in interface IRequestHandler2

Parameters:

request - The request that generated an error.

response - the response or null if the failure occurred before the response is made available

e - The error that resulted from executing the request.