CXF includes a provides the 'simple frontend which builds services from reflection. This is in contrast to the JAX-WS frontend which requires you to annotate your web service classes or create a WSDL first. The simple frontend will use reflection to intelligently map your classes to a WSDL model. ' frontend to map Java APIs to and from WSDL models for web services. The simple front end is much like JAX-WS, however, where JAX-WS uses Java annotations to specify detailed configuration (and, indeed, requires a few), Simple is willing to map a 'naked' interface or class to a service, and respects some configuration options from .aegis.xml files shared with the Aegis data binding.
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The JAX-WS frontend is far more flexible than the Simple frontend. There are only two reasons to select Simple over JAX-WS:
Other than these items, Simple has no advantages over JAX-WS. The implementation classes of JAX-WS in CXF are all subclasses of the implementation classes of Simple. In a 'simple' case, very nearly identical things happen in the Simple front end as in JAX-WS. CXF's extensions to JAX-WS, on the other hand, make it very 'simple' to use. |
Simple Pitfall: Unreliable Parameter Names
The typical pattern of a web service is to define a Service Endpoint Interface and then create a class that implements that interface. When you own both ends of the process, you can simply use the SEI in both the server and the client.
The problem has to do with a quirk of Java reflection. If a program uses Java reflection to examine a concrete method of a class, the data available may provide the parameter names from the source. The behavior of current Java compilers depends on whether you ask them to provide debug symbols. However, if a program uses reflection to look at an abstract method, current Java compilers never provide the parameter names.
If there are no names, Simple creates ugly parameters named arg0
, arg1
, ... Further, if you forget to specify the SEI when creating a service, and only provide the SEB, Simple will see your concrete methods and assign actual parameter names (if you have debug symbols). If you client uses the SEI, they won't communicate. If you change your mind about debug symbols, you will change the contract.
Thus, while JAX-WS @WebParam
annotations may seem noisy and inconvenient, they are, in fact, ensuring that your service has a consistent contract.
If you choose to use the Simple front end, you will need to use parameter
elements in a .aegis.xml
file to give useful names, or be sure to provide the SEI to the ServerFactoryBean
.
Simple and Data Bindings
By default CXF uses the JAXB databinding. If you are interested in a databinding which does not require annotations, please see the documentation on the Aegis Databinding (2.0.x).
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This is a historical default, but often not what you will want, both due to the pitfall described above and the JAX-B issue described at the bottom of this page. If you choose to use the Simple front end, we recommend that you use the Aegis databinding.
ServerFactoryBean – Making a Service Endpoint
The ServerFactoryBean produces a Server instance for you. It requires a service class and an address to publish the service on. By creating a Server you'll have started your service and made it available to the outside world.
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Your service is now started! You can access the wsdl at "http://localhost:9000/Hello?wsdl".
ClientProxyFactoryBean – Making a Client Proxy
You'll also want to create a client for your service. CXF includes a ClientProxyFactoryBean which will create a Java proxy for you from your interface which will invoke the service.
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Warning |
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There is a known issue for the JAXB data binding with POJO, please see Dan Kulp's comment in https://issues.apache.org/jira/browse/CXF-897 . |