/*
* 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.support.wrapper;
import java.util.List;
import com.alibaba.dubbo.common.Constants;
import com.alibaba.dubbo.common.URL;
import com.alibaba.dubbo.common.logger.Logger;
import com.alibaba.dubbo.common.logger.LoggerFactory;
import com.alibaba.dubbo.common.utils.StringUtils;
import com.alibaba.dubbo.rpc.Invocation;
import com.alibaba.dubbo.rpc.Invoker;
import com.alibaba.dubbo.rpc.Result;
import com.alibaba.dubbo.rpc.RpcException;
import com.alibaba.dubbo.rpc.RpcInvocation;
import com.alibaba.dubbo.rpc.RpcResult;
import com.alibaba.dubbo.rpc.cluster.Directory;
import com.alibaba.dubbo.rpc.support.MockInvoker;
/**
* @author chao.liuc
*/
public class MockClusterInvoker<T> implements Invoker<T>{
private static final Logger logger = LoggerFactory.getLogger(MockClusterInvoker.class);
private final Directory<T> directory ;
private final Invoker<T> invoker;
public MockClusterInvoker(Directory<T> directory, Invoker<T> invoker) {
this.directory = directory;
this.invoker = invoker;
}
public URL getUrl() {
return directory.getUrl();
}
public boolean isAvailable() {
return directory.isAvailable();
}
public void destroy() {
this.invoker.destroy();
}
public Class<T> getInterface() {
return directory.getInterface();
}
public Result invoke(Invocation invocation) throws RpcException {
Result result = null;
String value = directory.getUrl().getMethodParameter(invocation.getMethodName(), Constants.MOCK_KEY, Boolean.FALSE.toString()).trim();
if (value.length() == 0 || value.equalsIgnoreCase("false")){
//no mock
result = this.invoker.invoke(invocation);
} else if (value.startsWith("force")) {
if (logger.isWarnEnabled()) {
logger.info("force-mock: " + invocation.getMethodName() + " force-mock enabled , url : " + directory.getUrl());
}
//force:direct mock
result = doMockInvoke(invocation, null);
} else {
//fail-mock
try {
result = this.invoker.invoke(invocation);
}catch (RpcException e) {
if (e.isBiz()) {
throw e;
} else {
if (logger.isWarnEnabled()) {
logger.info("fail-mock: " + invocation.getMethodName() + " fail-mock enabled , url : " + directory.getUrl(), e);
}
result = doMockInvoke(invocation, e);
}
}
}
return result;
}
@SuppressWarnings({ "unchecked", "rawtypes" })
private Result doMockInvoke(Invocation invocation,RpcException e){
Result result = null;
Invoker<T> minvoker ;
List<Invoker<T>> mockInvokers = selectMockInvoker(invocation);
if (mockInvokers == null || mockInvokers.size() == 0){
minvoker = (Invoker<T>) new MockInvoker(directory.getUrl());
} else {
minvoker = mockInvokers.get(0);
}
try {
result = minvoker.invoke(invocation);
} catch (RpcException me) {
if (me.isBiz()) {
result = new RpcResult(me.getCause());
} else {
throw new RpcException(me.getCode(), getMockExceptionMessage(e, me), me.getCause());
}
//
} catch (Throwable me) {
throw new RpcException(getMockExceptionMessage(e, me), me.getCause());
}
return result;
}
private String getMockExceptionMessage(Throwable t, Throwable mt){
String msg = "mock error : " + mt.getMessage();
if (t != null){
msg = msg + ", invoke error is :" + StringUtils.toString(t);
}
return msg;
}
/**
* 返回MockInvoker
* 契约：
* directory根据invocation中是否有Constants.INVOCATION_NEED_MOCK，来判断获取的是一个normal invoker 还是一个 mock invoker
* 如果directorylist 返回多个mock invoker，只使用第一个invoker.
* @param invocation
* @return
*/
private List<Invoker<T>> selectMockInvoker(Invocation invocation){
//TODO generic invoker？
if (invocation instanceof RpcInvocation){
//存在隐含契约(虽然在接口声明中增加描述，但扩展性会存在问题.同时放在attachement中的做法需要改进
((RpcInvocation)invocation).setAttachment(Constants.INVOCATION_NEED_MOCK, Boolean.TRUE.toString());
//directory根据invocation中attachment是否有Constants.INVOCATION_NEED_MOCK，来判断获取的是normal invokers or mock invokers
List<Invoker<T>> invokers = directory.list(invocation);
return invokers;
} else {
return null ;
}
}
@Override
public String toString() {
return "invoker :" + this.invoker + ",directory: " + this.directory;
}
}