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.impl.cloud; 018 019import java.util.List; 020import java.util.concurrent.RejectedExecutionException; 021 022import org.apache.camel.CamelContext; 023import org.apache.camel.CamelContextAware; 024import org.apache.camel.cloud.ServiceChooser; 025import org.apache.camel.cloud.ServiceChooserAware; 026import org.apache.camel.cloud.ServiceDefinition; 027import org.apache.camel.cloud.ServiceDiscovery; 028import org.apache.camel.cloud.ServiceDiscoveryAware; 029import org.apache.camel.cloud.ServiceFilter; 030import org.apache.camel.cloud.ServiceFilterAware; 031import org.apache.camel.cloud.ServiceLoadBalancer; 032import org.apache.camel.cloud.ServiceLoadBalancerFunction; 033import org.apache.camel.support.ServiceSupport; 034import org.apache.camel.util.ObjectHelper; 035import org.apache.camel.util.ServiceHelper; 036import org.slf4j.Logger; 037import org.slf4j.LoggerFactory; 038 039public class DefaultServiceLoadBalancer 040 extends ServiceSupport 041 implements CamelContextAware, ServiceDiscoveryAware, ServiceChooserAware, ServiceFilterAware, ServiceLoadBalancer { 042 043 private static final Logger LOGGER = LoggerFactory.getLogger(DefaultServiceLoadBalancer.class); 044 045 private CamelContext camelContext; 046 private ServiceDiscovery serviceDiscovery; 047 private ServiceChooser serviceChooser; 048 private ServiceFilter serviceFilter; 049 050 public DefaultServiceLoadBalancer() { 051 } 052 053 // ************************************* 054 // Bean 055 // ************************************* 056 057 @Override 058 public CamelContext getCamelContext() { 059 return camelContext; 060 } 061 062 @Override 063 public void setCamelContext(CamelContext camelContext) { 064 this.camelContext = camelContext; 065 } 066 067 @Override 068 public ServiceDiscovery getServiceDiscovery() { 069 return serviceDiscovery; 070 } 071 072 @Override 073 public void setServiceDiscovery(ServiceDiscovery serverDiscovery) { 074 this.serviceDiscovery = serverDiscovery; 075 } 076 077 @Override 078 public ServiceChooser getServiceChooser() { 079 return serviceChooser; 080 } 081 082 @Override 083 public void setServiceChooser(ServiceChooser serverChooser) { 084 this.serviceChooser = serverChooser; 085 } 086 087 @Override 088 public void setServiceFilter(ServiceFilter serviceFilter) { 089 this.serviceFilter = serviceFilter; 090 } 091 092 @Override 093 public ServiceFilter getServiceFilter() { 094 return serviceFilter; 095 } 096 097 // ************************************* 098 // Lifecycle 099 // ************************************* 100 101 @Override 102 protected void doStart() throws Exception { 103 ObjectHelper.notNull(camelContext, "camel context"); 104 ObjectHelper.notNull(serviceDiscovery, "service discovery"); 105 ObjectHelper.notNull(serviceChooser, "service chooser"); 106 ObjectHelper.notNull(serviceFilter, "service serviceFilter"); 107 108 LOGGER.info("ServiceCall is using default load balancer with service discovery type: {}, service filter type: {} and service chooser type: {}", 109 serviceDiscovery.getClass(), 110 serviceFilter.getClass(), 111 serviceChooser.getClass()); 112 113 ServiceHelper.startService(serviceChooser); 114 ServiceHelper.startService(serviceDiscovery); 115 } 116 117 @Override 118 protected void doStop() throws Exception { 119 // Stop services if needed 120 ServiceHelper.stopService(serviceDiscovery); 121 ServiceHelper.stopService(serviceChooser); 122 } 123 124 // ************************************* 125 // Load Balancer 126 // ************************************* 127 128 @Override 129 public <T> T process(String serviceName, ServiceLoadBalancerFunction<T> function) throws Exception { 130 ServiceDefinition service; 131 132 List<ServiceDefinition> services = serviceDiscovery.getServices(serviceName); 133 if (services == null || services.isEmpty()) { 134 throw new RejectedExecutionException("No active services with name " + serviceName); 135 } else { 136 // filter services 137 services = serviceFilter.apply(services); 138 // let the client service chooser find which server to use 139 service = services.size() > 1 ? serviceChooser.choose(services) : services.get(0); 140 if (service == null) { 141 throw new RejectedExecutionException("No active services with name " + serviceName); 142 } 143 } 144 145 return function.apply(service); 146 } 147}