001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.camel.model;
018
019import java.util.List;
020import javax.xml.bind.annotation.XmlAccessType;
021import javax.xml.bind.annotation.XmlAccessorType;
022import javax.xml.bind.annotation.XmlAttribute;
023import javax.xml.bind.annotation.XmlRootElement;
024
025import org.apache.camel.Processor;
026import org.apache.camel.spi.Metadata;
027import org.apache.camel.spi.RouteContext;
028import org.apache.camel.util.CollectionStringBuffer;
029
030/**
031 * Route to be executed when Hystrix EIP executes fallback
032 */
033@Metadata(label = "eip,routing,circuitbreaker")
034@XmlRootElement(name = "onFallback")
035@XmlAccessorType(XmlAccessType.FIELD)
036public class OnFallbackDefinition extends OutputDefinition<OnFallbackDefinition> {
037
038    @XmlAttribute
039    @Metadata(label = "command", defaultValue = "false")
040    private Boolean fallbackViaNetwork;
041
042    public OnFallbackDefinition() {
043    }
044
045    @Override
046    public String toString() {
047        if (fallbackViaNetwork != null && fallbackViaNetwork) {
048            return "OnFallbackViaNetwork[" + getOutputs() + "]";
049        } else {
050            return "OnFallback[" + getOutputs() + "]";
051        }
052    }
053
054    @Override
055    public Processor createProcessor(RouteContext routeContext) throws Exception {
056        return this.createChildProcessor(routeContext, false);
057    }
058
059    @Override
060    public String getLabel() {
061        String name = fallbackViaNetwork != null && fallbackViaNetwork ? "onFallbackViaNetwork" : "onFallback";
062        CollectionStringBuffer buffer = new CollectionStringBuffer(name);
063        buffer.append("[");
064        List<ProcessorDefinition<?>> list = getOutputs();
065        for (ProcessorDefinition<?> type : list) {
066            buffer.append(type.getLabel());
067        }
068        buffer.append("]");
069        return buffer.toString();
070    }
071
072    public Boolean getFallbackViaNetwork() {
073        return fallbackViaNetwork;
074    }
075
076    /**
077     * Whether the fallback goes over the network.
078     * <p/>
079     * If the fallback will go over the network it is another possible point of failure and so it also needs to be
080     * wrapped by a HystrixCommand. It is important to execute the fallback command on a separate thread-pool,
081     * otherwise if the main command were to become latent and fill the thread-pool
082     * this would prevent the fallback from running if the two commands share the same pool.
083     */
084    public void setFallbackViaNetwork(Boolean fallbackViaNetwork) {
085        this.fallbackViaNetwork = fallbackViaNetwork;
086    }
087
088    public boolean isFallbackViaNetwork() {
089        // is default false
090        return fallbackViaNetwork != null && fallbackViaNetwork;
091    }
092
093}