Handlers and Chains

• Say you want a handler to be called every time LogTestService is called. You would use

<deployment xmlns="http://xml.apache.org/axis/wsdd/"
   xmlns:java="http://xml.apache.org/axis/wsdd/providers/java">

  <!-- define the logging handler configuration -->
 <handler name="track" type="java:samples.userguide.example4.LogHandler">
  <parameter name="filename" value="MyService.log"/>
 </handler>
 
 <!-- define the service, using the log handler we just defined -->
 <service name="LogTestService" provider="java:RPC">
  <requestFlow>
   <handler type="track"/>
  </requestFlow>
 
  <parameter name="className" value="samples.userguide.example4.Service"/>
  <parameter name="allowedMethods" value="*"/>
 </service>
</deployment>

• where the LogHandler is defined as

package samples.userguide.example4;

import org.apache.axis.AxisFault;
import org.apache.axis.Handler;
import org.apache.axis.MessageContext;
import org.apache.axis.handlers.BasicHandler;

import java.io.FileOutputStream;
import java.io.PrintWriter;
import java.util.Date;

public class LogHandler extends BasicHandler {
    public void invoke(MessageContext msgContext) throws AxisFault
    {
        /** Log an access each time we get invoked.
         */
        try {
            Handler serviceHandler = msgContext.getService();
            String filename = (String)getOption("filename");
            if ((filename == null) || (filename.equals("")))
                throw new AxisFault("Server.NoLogFile",
                                 "No log file configured for the LogHandler!",
                                    null, null);
            FileOutputStream fos = new FileOutputStream(filename, true);
            
            PrintWriter writer = new PrintWriter(fos);
            
            Integer numAccesses =
                             (Integer)serviceHandler.getOption("accesses");
            if (numAccesses == null)
                numAccesses = new Integer(0);
            
            numAccesses = new Integer(numAccesses.intValue() + 1);
            
            Date date = new Date();
            String result = date + ": service " +
                            msgContext.getTargetService() +
                            " accessed " + numAccesses + " time(s).";
            serviceHandler.setOption("accesses", numAccesses);
            
            writer.println(result);
            
            writer.close();
        } catch (Exception e) {
            throw AxisFault.makeFault(e);
        }
    }
}