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42.2. Working with Contexts in a Service Implementation
Overview
Context information is made available to service implementations using the
WebServiceContext
interface. From the WebServiceContext
object you can obtain a MessageContext
object that is populated with the current request's context properties in the application scope. You can manipulate the values of the properties, and they are propagated back through the response chain.
Note
The
MessageContext
interface inherits from the java.util.Map
interface. Its contents can be manipulated using the Map
interface's methods.
Obtaining a context
To obtain the message context in a service implementation do the following:
- Declare a variable of type
WebServiceContext
. - Decorate the variable with the
javax.annotation.Resource
annotation to indicate that the context information is being injected into the variable. - Obtain the
MessageContext
object from theWebServiceContext
object using thegetMessageContext()
method.ImportantgetMessageContext()
can only be used in methods that are decorated with the@WebMethod
annotation.
Example 42.2, “Obtaining a Context Object in a Service Implementation” shows code for obtaining a context object.
Example 42.2. Obtaining a Context Object in a Service Implementation
import javax.xml.ws.*; import javax.xml.ws.handler.*; import javax.annotation.*; @WebServiceProvider public class WidgetServiceImpl { @Resource WebServiceContext wsc; @WebMethod public String getColor(String itemNum) { MessageContext context = wsc.getMessageContext(); } ... }
Reading a property from a context
Once you have obtained the
MessageContext
object for your implementation, you can access the properties stored there using the get()
method shown in Example 42.3, “The MessageContext.get()
Method”.
Example 42.3. The MessageContext.get()
Method
V get(Object key);
Note
This
get()
is inherited from the Map
interface.
The
key
parameter is the string representing the property you want to retrieve from the context. The get()
returns an object that must be cast to the proper type for the property. Table 42.1, “Properties Available in the Service Implementation Context” lists a number of the properties that are available in a service implementation's context.
Important
Changing the values of the object returned from the context also changes the value of the property in the context.
Example 42.4, “Getting a Property from a Service's Message Context” shows code for getting the name of the WSDL
operation
element that represents the invoked operation.
Example 42.4. Getting a Property from a Service's Message Context
import javax.xml.ws.handler.MessageContext; import org.apache.cxf.message.Message; ... // MessageContext context retrieved in a previous example QName wsdl_operation = (QName)context.get(Message.WSDL_OPERATION);
Setting properties in a context
Once you have obtained the
MessageContext
object for your implementation, you can set properties, and change existing properties, using the put()
method shown in Example 42.5, “The MessageContext.put()
Method”.
Example 42.5. The MessageContext.put()
Method
V put(K key,
V value)
throws ClassCastException, IllegalArgumentException, NullPointerException;
If the property being set already exists in the message context, the
put()
method replaces the existing value with the new value and returns the old value. If the property does not already exist in the message context, the put()
method sets the property and returns null
.
Example 42.6, “Setting a Property in a Service's Message Context” shows code for setting the response code for an HTTP request.
Example 42.6. Setting a Property in a Service's Message Context
import javax.xml.ws.handler.MessageContext; import org.apache.cxf.message.Message; ... // MessageContext context retrieved in a previous example context.put(Message.RESPONSE_CODE, new Integer(404));
Supported contexts
Table 42.1, “Properties Available in the Service Implementation Context” lists the properties accessible through the context in a service implementation object.
Base Class | |
---|---|
Property Name | Description |
org.apache.cxf.message.Message | |
PROTOCOL_HEADERS [a] | Specifies the transport specific header information. The value is stored as a java.util.Map<String, List<String>> . |
RESPONSE_CODE [a] | Specifies the response code returned to the consumer. The value is stored as an Integer object. |
ENDPOINT_ADDRESS | Specifies the address of the service provider. The value is stored as a String . |
HTTP_REQUEST_METHOD [a] | Specifies the HTTP verb sent with a request. The value is stored as a String . |
PATH_INFO [a] |
Specifies the path of the resource being requested. The value is stored as a
String .
The path is the portion of the URI after the hostname and before any query string. For example, if an endpoint's URI is http://cxf.apache.org/demo/widgets the path is
/demo/widgets .
|
QUERY_STRING [a] |
Specifies the query, if any, attached to the URI used to invoke the request. The value is stored as a
String .
Queries appear at the end of the URI after a
? . For example, if a request is made to http://cxf.apache.org/demo/widgets?color the query is color .
|
MTOM_ENABLED | Specifies whether or not the service provider can use MTOM for SOAP attachments. The value is stored as a Boolean . |
SCHEMA_VALIDATION_ENABLED | Specifies whether or not the service provider validates messages against a schema. The value is stored as a Boolean . |
FAULT_STACKTRACE_ENABLED | Specifies if the runtime provides a stack trace along with a fault message. The value is stored as a Boolean . |
CONTENT_TYPE | Specifies the MIME type of the message. The value is stored as a String . |
BASE_PATH |
Specifies the path of the resource being requested. The value is stored as a
java.net.URL .
The path is the portion of the URI after the hostname and before any query string. For example, if an endpoint's URL is http://cxf.apache.org/demo/widgets the base path is
/demo/widgets .
|
ENCODING | Specifies the encoding of the message. The value is stored as a String . |
FIXED_PARAMETER_ORDER | Specifies whether the parameters must appear in the message in a particular order. The value is stored as a Boolean . |
MAINTAIN_SESSION | Specifies if the consumer wants to maintain the current session for future requests. The value is stored as a Boolean . |
WSDL_DESCRIPTION [a] | Specifies the WSDL document that defines the service being implemented. The value is stored as a org.xml.sax.InputSource object. |
WSDL_SERVICE [a] | Specifies the qualified name of the wsdl:service element that defines the service being implemented. The value is stored as a QName . |
WSDL_PORT [a] | Specifies the qualified name of the wsdl:port element that defines the endpoint used to access the service. The value is stored as a QName . |
WSDL_INTERFACE [a] | Specifies the qualified name of the wsdl:portType element that defines the service being implemented. The value is stored as a QName . |
WSDL_OPERATION [a] | Specifies the qualified name of the wsdl:operation element that corresponds to the operation invoked by the consumer. The value is stored as a QName . |
javax.xml.ws.handler.MessageContext | |
MESSAGE_OUTBOUND_PROPERTY | Specifies if a message is outbound. The value is stored as a Boolean . true specifies that a message is outbound. |
INBOUND_MESSAGE_ATTACHMENTS |
Contains any attachments included in the request message. The value is stored as a
java.util.Map<String, DataHandler> .
The key value for the map is the MIME Content-ID for the header.
|
OUTBOUND_MESSAGE_ATTACHMENTS |
Contains any attachments for the response message. The value is stored as a
java.util.Map<String, DataHandler> .
The key value for the map is the MIME Content-ID for the header.
|
WSDL_DESCRIPTION | Specifies the WSDL document that defines the service being implemented. The value is stored as a org.xml.sax.InputSource object. |
WSDL_SERVICE | Specifies the qualified name of the wsdl:service element that defines the service being implemented. The value is stored as a QName . |
WSDL_PORT | Specifies the qualified name of the wsdl:port element that defines the endpoint used to access the service. The value is stored as a QName . |
WSDL_INTERFACE | Specifies the qualified name of the wsdl:portType element that defines the service being implemented. The value is stored as a QName . |
WSDL_OPERATION | Specifies the qualified name of the wsdl:operation element that corresponds to the operation invoked by the consumer. The value is stored as a QName . |
HTTP_RESPONSE_CODE | Specifies the response code returned to the consumer. The value is stored as an Integer object. |
HTTP_REQUEST_HEADERS | Specifies the HTTP headers on a request. The value is stored as a java.util.Map<String, List<String>> . |
HTTP_RESPONSE_HEADERS | Specifies the HTTP headers for the response. The value is stored as a java.util.Map<String, List<String>> . |
HTTP_REQUEST_METHOD | Specifies the HTTP verb sent with a request. The value is stored as a String . |
SERVLET_REQUEST | Contains the servlet's request object. The value is stored as a javax.servlet.http.HttpServletRequest . |
SERVLET_RESPONSE | Contains the servlet's response object. The value is stored as a javax.servlet.http.HttpResponse . |
SERVLET_CONTEXT | Contains the servlet's context object. The value is stored as a javax.servlet.ServletContext . |
PATH_INFO |
Specifies the path of the resource being requested. The value is stored as a
String .
The path is the portion of the URI after the hostname and before any query string. For example, if an endpoint's URL is http://cxf.apache.org/demo/widgets the path is
/demo/widgets .
|
QUERY_STRING |
Specifies the query, if any, attached to the URI used to invoke the request. The value is stored as a
String .
Queries appear at the end of the URI after a
? . For example, if a request is made to http://cxf.apache.org/demo/widgets?color the query string is color .
|
REFERENCE_PARAMETERS | Specifies the WS-Addressing reference parameters. This includes all of the SOAP headers whose wsa:IsReferenceParameter attribute is set to true . The value is stored as a java.util.List . |
org.apache.cxf.transport.jms.JMSConstants | |
JMS_SERVER_HEADERS | Contains the JMS message headers. For more information see Section 42.4, “Working with JMS Message Properties”. |
[a]
When using HTTP this property is the same as the standard JAX-WS defined property.
|