Working with JMS Message Properties

The Celtix Enterprise JMS transport has a context mechanism that can be used to inspect a JMS message's properties. The context mechanism can also be used to set a JMS message's properties.

Inspecting JMS Message Headers

Consumers and services use different context mechanisms to access the JMS message header properties. However, both mechanisms return the header properties as a org.apache.cxf.transports.jms.context.JMSMessageHeadersType object.

Getting the JMS Message Headers in a Service

Procedure

To get the JMS message header properties from the WebServiceContext do the following:

Declare a protected WebServiceContext field in your service's implementation class and annotate it with the JAX-WS @Resource annotation.
Get the message context from the WebServiceContext object using its getMessageContext() method.
Get the JMS message headers from the message context using the message context's get() method with the parameter org.apache.cxf.transports.jms.JMSConstants.JMS_SERVER_HEADERS.

Example

Example 8.3, “Getting JMS Message Headers in a Service” shows code for getting the JMS message headers from a service's message context:

Example 8.3. Getting JMS Message Headers in a Service

import org.apache.cxf.transport.jms.JMSConstants;
import org.apache.cxf.transports.jms.context.JMSMessageHeadersType;
            
@WebService(serviceName = "HelloWorldService", 
                           portName = "HelloWorldPort",
                           endpointInterface = "org.apache.cxf.hello_world_jms.HelloWorldPortType",
                           targetNamespace = "http://cxf.apache.org/hello_world_jms")
  public class GreeterImplTwoWayJMS implements HelloWorldPortType
  {
    @Resource
    protected WebServiceContext wsContext;
    ...
    public String greetMe(String me)
    {
      MessageContext mc = wsContext.getMessageContext();
      JMSMessageHeadersType headers = (JMSMessageHeadersType) mc.get(JMSConstants.JMS_SERVER_HEADERS);
       ... 
     }
      ...
}

Getting JMS Message Header Properties in a Consumer

Once a message has been successfully retrieved from the JMS transport you can inspect the JMS header properties using the consumer's response context. In addition, you can see how long the client will wait for a response before timing out.

Procedure

To get the JMS message headers from a consumer's response context do the following:

Get the proxy's invocation handler using the proxy's getInvocationHander() method.
If the invocation handler is an instance of BindingProvider, cast the invocation handler to a BindingProviderobject.
Get the response context using the binding provider's getResponseContext() method.
Get the JMS message header properties from the response context using the context's get() method with org.apache.cxf.transports.jms.JMSConstants.JMS_CLIENT_RESPONSE_HEADERS as the parameter.
Cast the returned object to org.apache.cxf.transports.jms.context.JMSMessageHeaderType.

Example

Example 8.4, “Getting the JMS Headers from a Consumer Response Header” shows code for getting the JMS message header properties from a consumer's response context.

Example 8.4. Getting the JMS Headers from a Consumer Response Header

import org.apache.cxf.transports.jms.context.*;
// Proxy greeter initialized previously
 InvocationHandler handler = Proxy.getInvocationHandler(greeter); 

// Invoke on greeter proxy

BindingProvider bp= null;
if (handler instanceof BindingProvider)
 {
  bp = (BindingProvider)handler;
  Map<String, Object> responseContext = bp.getResponseContext();
  JMSMessageHeadersType responseHdr = (JMSMessageHeadersType)
                           responseContext.get(JMSConstants.JMS_CLIENT_REQUEST_HEADERS);
...
}

The code in Example 8.4, “Getting the JMS Headers from a Consumer Response Header” does the following:

	Gets the `InvocationHandler` for the proxy whose message headers you want to inspect.
	Checks to see if the `InvocationHandler` is a `BindingProvider` object.
	Casts the returned `InvocationHandler` object into a `BindingProvider` object to retrieve the response context.
	Gets the response context.
	Retrieves the JMS message headers from the response context.

Inspecting the Message Header Properties

Standard JMS Header Properties

Table 8.2, “JMS Header Properties” lists the standard properties in the JMS header that you can inspect.

Table 8.2. JMS Header Properties

Property Name	Property Type	Getter Method
Correlation ID	string	`getJMSCorralationID()`
Delivery Mode	int	`getJMSDeliveryMode()`
Message Expiration	long	`getJMSExpiration()`
Message ID	string	`getJMSMessageID()`
Priority	int	`getJMSPriority()`
Redelivered	boolean	`getJMSRedlivered()`
Time Stamp	long	`getJMSTimeStamp()`
Type	string	`getJMSType()`
Time To Live	long	`getTimeToLive()`

Optional Header Properties

In addition, you can inspect any optional properties stored in the JMS header using JMSMessageHeadersType.getProperty(). The optional properties are returned as a List of org.apache.cxf.transports.jms.context.JMSPropertyType. Optional properties are stored as name/value pairs.

Example

Example 8.5, “Reading the JMS Header Properties” shows code for inspecting some of the JMS properties using the response context.

Example 8.5. Reading the JMS Header Properties

// JMSMessageHeadersType messageHdr retrieved previously
System.out.println("Correlation ID: "+messageHdr.getJMSCorrelationID());
System.out.println("Message Priority: "+messageHdr.getJMSPriority());
System.out.println("Redelivered: "+messageHdr.getRedelivered());
  
JMSPropertyType prop = null;
List<JMSPropertyType> optProps = messageHdr.getProperty();
Iterator<JMSPropertyType> iter = optProps.iterator();
while (iter.hasNext())
{
  prop = iter.next();
   System.out.println("Property name: "+prop.getName());
   System.out.println("Property value: "+prop.getValue());
}

The code in Example 8.5, “Reading the JMS Header Properties” does the following:

	Prints the value of the message's correlation ID.
	Prints the value of the message's priority property.
	Prints the value of the message's redelivered property.
	Gets the list of the message's optional header properties.
	Gets an `Iterator` to traverse the list of properties.
	Iterates through the list of optional properties and prints their name and value.

Setting JMS Properties

Using the request context in a consumer endpoint, you can set a number of the JMS message header properties and the consumer endpoint's timeout value. These properties are valid for a single invocation. You will need to reset them each time you invoke an operation on the service proxy.

	Note
	You cannot set header properties in a service.

JMS Header Properties

Table 8.3, “Settable JMS Header Properties” lists the properties in the JMS header that you can set using the consumer endpoint's request context.

Table 8.3. Settable JMS Header Properties

Property Name	Property Type	Setter Method
Correlation ID	string	`setJMSCorralationID()`
Delivery Mode	int	`setJMSDeliveryMode()`
Priority	int	`setJMSPriority()`
Time To Live	long	`setTimeToLive()`

To set these properties do the following:

Create an org.apache.cxf.transports.jms.context.JMSMessageHeadersType object.
Populate the values you wish to set using the appropriate setter methods from Table 8.3, “Settable JMS Header Properties”.
Set the values into the request context by calling the request context's put() method using org.apache.cxf.transports.jms.JMSConstants.JMS_CLIENT_REQUEST_HEADERS as the first argument and the new JMSMessageHeadersType object as the second argument.

Optional JMS Header Properties

You can also set optional properties into the JMS header. Optional JMS header properties are stored in the JMSMessageHeadersType object that is used to set the other JMS header properties. They are stored as a List of org.apache.cxf.transports.jms.context.JMSPropertyType. To add optional properties to the JMS header do the following:

Create a JMSPropertyType object.
Set the property's name field using setName().
Set the property's value field using setValue().
Add the property to the JMS message header to the JMS message header using JMSMessageHeadersType.getProperty().add(JMSPropertyType).
Repeat the procedure until all of the properties have been added to the message header.

Client Receive Timeout

In addition to the JMS header properties, you can set the amount of time a consumer endpoint will wait for a response before timing out. You set the value by calling the request context's put() method with org.apache.cxf.transports.jms.JMSConstants.JMS_CLIENT_RECEIVE_TIMEOUT as the first argument and a long representing the amount of time in milliseconds that you want to consumer to wait as the second argument.

Example

Example 8.6, “Setting JMS Properties using the Request Context” shows code for setting some of the JMS properties using the request context.

Example 8.6. Setting JMS Properties using the Request Context

import org.apache.cxf.transports.jms.context.*;
 // Proxy greeter initialized previously
InvocationHandler handler = Proxy.getInvocationHandler(greeter);


BindingProvider bp= null;
if (handler instanceof BindingProvider)
{
  bp = (BindingProvider)handler;
  Map<String, Object> requestContext = bp.getRequestContext();
  
  JMSMessageHeadersType requestHdr = new JMSMessageHeadersType();
  requestHdr.setJMSCorrelationID("WithBob");
  requestHdr.setJMSExpiration(3600000L);
  
  
  JMSPropertyType prop = new JMSPropertyType;
  prop.setName("MyProperty");
  prop.setValue("Bluebird");
  requestHdr.getProperty().add(prop);

  requestContext.put(JMSConstants.CLIENT_REQUEST_HEADERS, requestHdr);

  requestContext.put(JMSConstants.CLIENT_RECEIVE_TIMEOUT, new Long(1000));
}

The code in Example 8.6, “Setting JMS Properties using the Request Context” does the following:

	Gets the `InvocationHandler` for the proxy whose JMS properties you want to change.
	Checks to see if the `InvocationHandler` is a `BindingProvider`.
	Casts the returned `InvocationHandler` object into a `BindingProvider` object to retrieve the request context.
	Gets the request context.
	Creates a `JMSMessageHeadersType` object to hold the new message header values.
	Sets the Correlation ID.
	Sets the Expiration property to 60 minutes.
	Creates a new `JMSPropertyType` object.
	Sets the values for the optional property.
	Adds the optional property to the message header.
	Sets the JMS message header values into the request context.
	Sets the client receive timeout property to 1 second.