You can enable an existing Java API
for XML-Based Web Services (JAX-WS) Web services client to retrieve
values from transport headers. For a request that uses HTTP, the transport
headers are retrieved from HTTP headers found in the HTTP response
message. For a request that uses Java Message
Service (JMS), the transport headers are retrieved from the JMS message
properties found on the JMS response message.
Before you begin
You need a JAX-WS Web services client that you can enable
to retrieve transport headers.
Retrieving transport headers is
supported only by Web services clients, and only supported for the
HTTP and JMS transports. The Web services client must call the JAX-WS
APIs directly and not through any intermediary layers, such as a gateway
function. Sending and retrieving transport headers on the Web services
server is done through non-Web services APIs.
About this task
When using the JAX-WS programming model, the client must
set a property on the BindingProvider object to retrieve values from
the transport headers. After you set the property, values are read
from responses for the subsequent method invocations against that
BindingProvider object until the associated property is set to null or
the BindingProvider object is discarded.
Complete the following
actions modify the client code to retrieve values from the transport
headers on inbound responses.
Procedure
- Create a java.util.HashMap object that contains the names
of the transport headers to be retrieved from incoming response messages.
Avoid trouble: This step only applies
if you are running on Version 7.0.0.13 or earlier
gotcha
- Add an entry to the HashMap for each header that you want
to retrieve a value from every incoming response message.
Avoid trouble: This step only
applies if you are running on Version 7.0.0.13 or earlier
gotcha
- Set the HashMap entry key to a string that exactly matches
the transport header identifier. You can define the header
identifier with a reserved header name, such as Cookie in the case
of HTTP, or the header identifier can be user-defined, such as MyTransportHeader.
Certain header identifiers are processed in a unique manner, but no
other checks are made to confirm the header identifier value. To learn
more about the HTTP header identifiers that have unique consideration,
read about transport header properties best practices. You can find
common header identifier string constants, such as HTTP_HEADER_SET_COOKIE
in the com.ibm.websphere.webservices.Constants class. The HashMap
entry value is ignored and does not need to be set. An empty HashMap,
for example, one that is non-null, but does not contain any keys,
causes all the transport headers in the response to be retrieved.
- Set the HashMap entry on the BindingProvider instance using
the com.ibm.websphere.webservices.Constants.RESPONSE_TRANSPORT_PROPERTIES
property.
Avoid trouble: This step
only applies if you are running on Version 7.0.0.13 or earlier
gotcha
When
the HashMap is set, the RESPONSE_TRANSPORT_PROPERTIES property is
used in subsequent invocations to retrieve the headers from the responses.
If you set the property to null, no headers are retrieved
from the response. To learn more about these properties, see the transport
header properties documentation.
- Issue remote method calls against the BindingProvider instance.
Avoid trouble: This step only applies
if you are running on Version 7.0.0.13 or earlier
gotcha
The
values from the specified transport headers are retrieved from the
response message and placed in the HashMap.
If the property
is not set correctly, you might experience API usage errors that result
in a WebServiceException error. The following requirements must be
met, or the process fails:
- The property value that is set on the BindingProvider instance
must be either null or an instance of a HashMap.
- All the HashMap keys must be a string data type, and the keys
must not be null.
Create a java.util.Map object that
will hold the transport headers retrieved from the response message.
To retrieve all the transport headers from a response message,
leave this Map empty.
(Optional) Add an entry to the Map
for each header that you want to retrieve from the incoming response
message.
- Set the Map entry key to a string that exactly matches
the transport header identifier. You can specify the header
identifier with a reserved header name, such as Cookie in the case
of HTTP, or the header identifier can be user-defined, such as MyTransportHeader.
Certain header identifiers are processed in a unique manner, but no
other checks are made to confirm the header identifier value. To learn
more about the HTTP header identifiers that have unique consideration,
read about transport header properties best practices. You can find
common header identifier string constants, such as HTTP_HEADER_SET_COOKIE
in the com.ibm.websphere.webservices.Constants class. The Map entry
value is ignored and does not need to be set. An empty Map, for example,
one that is non-null, but does not contain any keys, causes all the
transport headers in the response to be retrieved.
Set the Map object on the BindingProvider's
RequestContext using the com.ibm.websphere.webservices.Constants.RESPONSE_TRANSPORT_PROPERTIES
property. When the Map is set, the RESPONSE_TRANSPORT_PROPERTIES
property is used in subsequent invocations to retrieve the headers
from the responses. If you set the property to null,
no headers are retrieved from the response. To learn more about these
properties, see the transport header properties documentation.
Invoke remote method calls against
the BindingProvider instance. The values from the specified
transport headers are retrieved from the response message and placed
in the Map.If the property is not set correctly, you might experience
API usage errors that result in a WebServiceException error. The following
requirements must be met, or the process fails:
- The Constants.RESPONSE_TRANSPORT_PROPERTIES property value that
is set on the BindingProvider's RequestContext instance must
be either null or an instance of java.util.Map.
- All the Map keys must be of the java.lang.String data type, and
the keys must not be null.
- The Map may be empty, which means that it contains no entries
at all. In this case, all the transport headers will be retrieved
from the response message.
Results
You have a JAX-WS Web service that can receive transport
headers from incoming response messages.