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.loadbalancer;
018
019import javax.xml.bind.annotation.XmlAccessType;
020import javax.xml.bind.annotation.XmlAccessorType;
021import javax.xml.bind.annotation.XmlElement;
022import javax.xml.bind.annotation.XmlRootElement;
023
024import org.apache.camel.model.ExpressionSubElementDefinition;
025import org.apache.camel.model.LoadBalancerDefinition;
026import org.apache.camel.processor.loadbalancer.LoadBalancer;
027import org.apache.camel.processor.loadbalancer.StickyLoadBalancer;
028import org.apache.camel.spi.Metadata;
029import org.apache.camel.spi.RouteContext;
030
031/**
032 * Sticky load balancer
033 *
034 * Sticky load balancing using an Expression to calculate a correlation key to perform the sticky load balancing;
035 * rather like jsessionid in the web or JMSXGroupID in JMS.
036 */
037@Metadata(label = "configuration,loadbalance")
038@XmlRootElement(name = "sticky")
039@XmlAccessorType(XmlAccessType.FIELD)
040public class StickyLoadBalancerDefinition extends LoadBalancerDefinition {
041    @XmlElement(name = "correlationExpression", required = true)
042    private ExpressionSubElementDefinition correlationExpression;
043
044    public StickyLoadBalancerDefinition() {
045    }
046
047    @Override
048    protected LoadBalancer createLoadBalancer(RouteContext routeContext) {
049        return new StickyLoadBalancer(correlationExpression.createExpression(routeContext));
050    }
051
052    public ExpressionSubElementDefinition getCorrelationExpression() {
053        return correlationExpression;
054    }
055
056    /**
057     * The correlation expression to use to calculate the correlation key
058     */
059    public void setCorrelationExpression(ExpressionSubElementDefinition correlationExpression) {
060        this.correlationExpression = correlationExpression;
061    }
062
063    @Override
064    public String toString() {
065        return "StickyLoadBalancer[" + correlationExpression + "]";
066    }
067}