org.fabric3.implementation.spring.runtime.component.SpringEventStreamHandler Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of fabric3-spring Show documentation
Fabric3
The newest version!
/*
 * Fabric3
 * Copyright (c) 2009-2015 Metaform Systems
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Portions originally based on Apache Tuscany 2007
 * licensed under the Apache 2.0 license.
 */
package org.fabric3.implementation.spring.runtime.component;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import org.fabric3.spi.container.channel.EventStreamHandler;
import org.fabric3.spi.container.invocation.WorkContextCache;
import org.fabric3.spi.model.type.java.JavaType;
import org.fabric3.spi.container.wire.InvocationRuntimeException;
import org.oasisopen.sca.ServiceRuntimeException;
import org.springframework.beans.BeansException;

/**
 * Responsible for dispatching an event to a Spring bean.
 */
public class SpringEventStreamHandler implements EventStreamHandler {
    private String beanName;
    private String consumerName;
    private JavaType type;
    private SpringComponent component;
    private ClassLoader targetTCCLClassLoader;
    private Object beanProxy;
    private Method beanMethod;

    /**
     * Constructor.
     *
     * @param beanName   the name of the bean events are dispatched to
     * @param methodName the name of the bean method events are dispatched to
     * @param type       the event type
     * @param component  the target component
     */
    public SpringEventStreamHandler(String beanName, String methodName, JavaType type, SpringComponent component) {
        this.beanName = beanName;
        this.consumerName = methodName;
        this.type = type;
        this.component = component;
        targetTCCLClassLoader = component.getClassLoader();
    }

    public void handle(Object event, boolean endOfBatch) {
        try {
            if (beanProxy == null) {
                beanProxy = component.getBean(beanName);
                if (beanProxy == null) {
                    throw new ServiceRuntimeException("Bean not found:" + beanName);
                }
            }
            WorkContextCache.getAndResetThreadWorkContext();
            ClassLoader old = Thread.currentThread().getContextClassLoader();
            try {
                Thread.currentThread().setContextClassLoader(targetTCCLClassLoader);
                getConsumerMethod().invoke(beanProxy, event);
            } finally {
                Thread.currentThread().setContextClassLoader(old);
            }
        } catch (InvocationTargetException e) {
            Throwable cause = e.getCause();
            Package pkg = cause.getClass().getPackage();
            if (cause instanceof RuntimeException && pkg != null && pkg.getName().startsWith("org.springframework.")) {
                // an exception generated by Spring - treat it as an infrastructure failure
                throw  new ServiceRuntimeException(cause);
            }
            // TODO Log
        } catch (IllegalAccessException e) {
            throw new InvocationRuntimeException(e);
        } catch (BeansException e) {
            // this should not happen at this point
            throw new InvocationRuntimeException("Error invoking bean: " + beanName, e);
        }
    }

    public void setNext(EventStreamHandler next) {
        throw new IllegalStateException("This handler must be the last one in the handler sequence");
    }

    public EventStreamHandler getNext() {
        return null;
    }

    /**
     * Resolves the consumer method on the target bean after the Spring component has been started.
     *
     * @return the bean consumer method
     */
    private Method getConsumerMethod() {
        if (beanMethod != null) {
            return beanMethod;
        }
        Class beanClass = component.getBeanClass(beanName);
        for (Method method : beanClass.getMethods()) {
            Class[] params = method.getParameterTypes();
            // setters are only supported
            if (params.length == 1 && method.getName().equals(consumerName) && params[0].isAssignableFrom(type.getType())) {
                beanMethod = method;
                return beanMethod;
            }
        }
        throw new ServiceRuntimeException("Could not load method with type: " + type);
    }

}