org.openamf.invoker.JavaServiceInvoker.java Source code

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Here is the source code for org.openamf.invoker.JavaServiceInvoker.java

Source

/*
 * www.openamf.org
 *
 * Distributable under LGPL license.
 * See terms of license at gnu.org.
 */

package org.openamf.invoker;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.openamf.ServiceRequest;

/**
 * @author Jason Calabrese <jasonc@missionvi.com>
 * @author Sean C. Sullivan
 * 
 * @version $Revision: 1.29 $, $Date: 2004/08/15 18:12:30 $
 */
public class JavaServiceInvoker extends ServiceInvoker {

    private static final Log log = LogFactory.getLog(JavaServiceInvoker.class);

    public JavaServiceInvoker(ServiceRequest request, HttpServletRequest httpServletRequest,
            ServletContext servletContex) {

        super(request, httpServletRequest, servletContex);
    }

    public Object invokeService() throws ServiceInvocationException {
        Class serviceClass = null;
        Object service = null;
        Object serviceResult = null;

        try {
            serviceClass = loadClass(request.getServiceName());
            service = getPersistentServiceObject();
            if (service == null) {
                service = serviceClass.newInstance();
            }
            serviceResult = invokeServiceMethod(service, serviceClass, request.getServiceMethodName(),
                    request.getParameters());
            setPersistentServiceObject(service);
        } catch (InvocationTargetException e) {
            //use the cause since the exception is thrown when 
            //the service method throws an exception
            throw new ServiceInvocationException(request, e.getTargetException());
        } catch (Exception e) {
            throw new ServiceInvocationException(request, e);
        }

        return serviceResult;
    }

    public boolean getPersistService() {
        boolean result = false;
        Class serviceClass = null;
        try {
            serviceClass = loadClass(request.getServiceName());
            if (java.io.Serializable.class.isAssignableFrom(serviceClass)) {
                result = true;
            } else {
                result = false;
            }
        } catch (ClassNotFoundException ex) {
            result = false;
        }
        return result;
    }

    public String getPersistentServiceName() {
        return request.getServiceName();
    }

    protected Object invokeServiceMethod(Object service, Class serviceClass, String methodName, List parameters)
            throws SecurityException, NoSuchMethodException, IllegalArgumentException, IllegalAccessException,
            InvocationTargetException {

        RankedMethod serviceMethod = getServiceMethod(serviceClass, methodName, parameters);
        return serviceMethod.invoke(service);

    }

    private RankedMethod getServiceMethod(Class serviceClass, String methodName, List parameters)
            throws SecurityException, NoSuchMethodException {

        RankedMethod serviceMethod = null;
        Method[] methods = serviceClass.getMethods();
        List rankedMethods = new ArrayList(methods.length);

        log.debug("REQUESTED methodName: " + methodName);

        for (int i = 0; i < methods.length; i++) {
            Method method = methods[i];
            RankedMethod rankedMethod = new RankedMethod(method, methodName, parameters);
            if (rankedMethod.isInvokable()) {
                //only added invokable methods to list
                rankedMethods.add(rankedMethod);
            }
        }

        if (rankedMethods.size() > 0) {
            Collections.sort(rankedMethods);
            RankedMethod topRankedMethod = (RankedMethod) rankedMethods.get(0);
            log.info("topRankedMethod: name=" + topRankedMethod.getMethod().getName() + " rank="
                    + topRankedMethod.getRank());
            serviceMethod = topRankedMethod;
        }

        if (serviceMethod == null) {
            String errorDesc = serviceClass + "." + methodName + "(" + parameters + ")";
            log.warn("Method Not Found: " + errorDesc);
            throw new NoSuchMethodException(errorDesc);
        }

        return serviceMethod;
    }

    static private Class loadClass(String className) throws ClassNotFoundException {
        Class cl = null;

        cl = Thread.currentThread().getContextClassLoader().loadClass(className);

        return cl;
    }

    public boolean supports(ServiceRequest request) {
        if (request != null) {
            log.debug("check supports " + request.getServiceName());
        }
        boolean supports = false;
        try {
            loadClass(request.getServiceName());
            supports = true;
        } catch (Exception e) {
            log.debug("exception", e);
        }
        return supports;
    }

}