| /*
|
| * Copyright 1999-2011 Alibaba Group.
|
| *
|
| * 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.
|
| */
|
| package com.alibaba.dubbo.rpc.cluster.loadbalance; |
| |
| import java.util.List; |
| |
| import com.alibaba.dubbo.common.Adaptive; |
| import com.alibaba.dubbo.common.Constants; |
| import com.alibaba.dubbo.common.ExtensionLoader; |
| import com.alibaba.dubbo.common.URL; |
| import com.alibaba.dubbo.rpc.Invocation; |
| import com.alibaba.dubbo.rpc.Invoker; |
| import com.alibaba.dubbo.rpc.RpcException; |
| import com.alibaba.dubbo.rpc.cluster.LoadBalance; |
| |
| /** |
| * LoadBalanceAdptive |
| * |
| * @author ding.lid |
| * @author william.liangf |
| */ |
| @Adaptive |
| public class LoadBalanceAdptive implements LoadBalance { |
| public <T> Invoker<T> select(List<Invoker<T>> invokers, Invocation invocation) throws RpcException { |
| if (invokers == null || invokers.size() == 0) { |
| return null; |
| } |
| URL url = invokers.get(0).getUrl(); |
| String method = invocation.getMethodName(); |
| String name; |
| if (method == null || method.length() == 0) { |
| name = url.getParameter(Constants.LOADBALANCE_KEY, Constants.DEFAULT_LOADBALANCE); |
| } else { |
| name = url.getMethodParameter(method, Constants.LOADBALANCE_KEY, Constants.DEFAULT_LOADBALANCE); |
| } |
| LoadBalance loadbalance = ExtensionLoader.getExtensionLoader(LoadBalance.class).getExtension(name); |
| return loadbalance.select(invokers, invocation); |
| } |
| } |