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.Expression; 025import org.apache.camel.model.ExpressionNodeHelper; 026import org.apache.camel.model.ExpressionSubElementDefinition; 027import org.apache.camel.model.LoadBalancerDefinition; 028import org.apache.camel.model.language.ExpressionDefinition; 029import org.apache.camel.processor.loadbalancer.LoadBalancer; 030import org.apache.camel.processor.loadbalancer.StickyLoadBalancer; 031import org.apache.camel.spi.Metadata; 032import org.apache.camel.spi.RouteContext; 033 034/** 035 * Sticky load balancer 036 * 037 * Sticky load balancing using an Expression to calculate a correlation key to perform the sticky load balancing; 038 * rather like jsessionid in the web or JMSXGroupID in JMS. 039 */ 040@Metadata(label = "eip,routing,loadbalance") 041@XmlRootElement(name = "sticky") 042@XmlAccessorType(XmlAccessType.FIELD) 043public class StickyLoadBalancerDefinition extends LoadBalancerDefinition { 044 @XmlElement(name = "correlationExpression", required = true) 045 private ExpressionSubElementDefinition correlationExpression; 046 047 public StickyLoadBalancerDefinition() { 048 } 049 050 @Override 051 protected LoadBalancer createLoadBalancer(RouteContext routeContext) { 052 return new StickyLoadBalancer(correlationExpression.createExpression(routeContext)); 053 } 054 055 public ExpressionSubElementDefinition getCorrelationExpression() { 056 return correlationExpression; 057 } 058 059 /** 060 * The correlation expression to use to calculate the correlation key 061 */ 062 public void setCorrelationExpression(ExpressionSubElementDefinition correlationExpression) { 063 this.correlationExpression = correlationExpression; 064 } 065 066 public void setCorrelationExpression(Expression expression) { 067 ExpressionDefinition def = ExpressionNodeHelper.toExpressionDefinition(expression); 068 this.correlationExpression = new ExpressionSubElementDefinition(); 069 this.correlationExpression.setExpressionType(def); 070 } 071 072 @Override 073 public String toString() { 074 return "StickyLoadBalancer[" + correlationExpression + "]"; 075 } 076}