Logging Messages

CXF uses Java SE Logging for both client- and server-side logging of SOAP requests and responses. Logging is activated by use of separate in/out interceptors that can be attached to the client and/or service as required. These interceptors can be specified either programmatically (via Java code and/or annotations) or via use of configuration files.

Configuration files are probably best. They offer two benefits over programmatic configuration:

1. Logging requirements can be altered without needing to recompile the code
2. No Apache CXF-specific APIs need to be added to your code, which helps it remain interoperable with other JAX-WS compliant web service stacks

Enabling message logging through configuration files is shown here.

For programmatic configuration, the logging interceptors can be added to your service endpoint as follows:

import javax.xml.ws.Endpoint;
import org.apache.cxf.interceptor.LoggingInInterceptor;
import org.apache.cxf.interceptor.LoggingOutInterceptor;
import org.apache.cxf.jaxws.EndpointImpl;

Object implementor = new GreeterImpl();
EndpointImpl ep = (EndpointImpl) Endpoint.publish("http://localhost/service", implementor);

ep.getServer().getEndpoint().getInInterceptors().add(new LoggingInInterceptor());
ep.getServer().getEndpoint().getOutInterceptors().add(new LoggingOutInterceptor());

For web services running on CXFServlet, the below annotations can be used on either the SEI or the SEI implementation class. If placed on the SEI, they activate logging both for client and server; if on the SEI implementation class, they are relevant just for server-side logging.

import org.apache.cxf.feature.Features;

@javax.jws.WebService(portName = "MyWebServicePort", serviceName = "MyWebService", ...)
@Features(features = "org.apache.cxf.feature.LoggingFeature")        
public class MyWebServicePortTypeImpl implements MyWebServicePortType {

or (equivalent)

import org.apache.cxf.interceptor.InInterceptors;
import org.apache.cxf.interceptor.OutInterceptors;

@javax.jws.WebService(portName = "WebServicePort", serviceName = "WebServiceService", ...)
@InInterceptors(interceptors = "org.apache.cxf.interceptor.LoggingInInterceptor")
@OutInterceptors(interceptors = "org.apache.cxf.interceptor.LoggingOutInterceptor")
public class WebServicePortTypeImpl implements WebServicePortType {

For programmatic client-side logging, the following code snippet can be used as an example:

import org.apache.cxf.endpoint.Client;
import org.apache.cxf.frontend.ClientProxy;
import org.apache.cxf.interceptor.LoggingInInterceptor;
import org.apache.cxf.interceptor.LoggingOutInterceptor;

public class WSClient {
    public static void main (String[] args) {
        MyService ws = new MyService();
        MyPortType port = ws.getPort();
        
        Client client = ClientProxy.getClient(port);
        client.getInInterceptors().add(new LoggingInInterceptor());
        client.getOutInterceptors().add(new LoggingOutInterceptor()); 
        
        // make WS calls...

Configure logging levels.

In the /etc folder of the CXF distribution there is a sample Java SE logging.properties file you can use to configure logging. For example, if you want to change the console logging level from WARNING to FINE, you need to update two properties in this logging.properties file as below:

.level= FINE
java.util.logging.ConsoleHandler.level = FINE

Once this is done, you will need to set the -Djava.util.logging.config.file property to the location of the logging.properties file. As an example, the Ant target below has this property set:

<target name="runClient">
   <java classname="client.WSClient" fork="true">	    	
      <classpath>
         <pathelement location="${build.classes.dir}"/>
         <fileset dir="${env.CXF_HOME}/lib">
            <include name="*.jar"/>
         </fileset>
      </classpath>
      <jvmarg value="-Djava.util.logging.config.file=/usr/myclientapp/logging.properties"/>
   </java>
</target>

Using Log4j Instead of java.util.logging

As noted above, CXF uses the java.util.logging package by default. But it is possible to switch CXF to instead use Log4J. This is achieved through the use of configuration files. There are two options to bootstrapping CXF logging and each is listed below:

• Add the following system property to the classpath from which CXF is initialized:

-Dorg.apache.cxf.Logger=org.apache.cxf.common.logging.Log4jLogger

• Add the file META-INF/cxf/org.apache.cxf.Logger to the classpath and make sure it contains the following content:

org.apache.cxf.common.logging.Log4jLogger

Debugging Tools

Eclipse IDE

See this blog entry for information on debugging web services using Eclipse. Note this is primarily for tracing/debugging source code; you will probably still want to use one of the tools below to capture network traffic, view SOAP requests and responses, etc.

Tcpmon

TCPMon allows you to easily view messages as they go back and forth on the wire.

WSMonitor

WSMonitor has slightly more functionality than Tcpmon. Information on how to reconfigure clients to work with WSMonitor is available in this blog entry.

SOAP UI

SOAP UI can also be used for debugging. In addition to viewing messages, it allows you send messages and load test your services. It also has plugins for Eclipse, IDEA and NetBeans.

Wireshark

Wireshark, a network packet analyzer, can be helpful in case you are getting cryptic WstxUnexpectedCharException errors from CXF's Woodstox StAX processor. This error can indicate a non-XML response from the server (e.g., an HTML error message) that Woodstox can't process. In these cases, Wireshark can help with troubleshooting by providing you the non-XML response data. See this blog entry for more information.