配置初始化
ReferenceBean
跟ServiceBean
一样,都实现了InitializingBean
的接口,自然也会调用afterPropertiesSet
方法在,这个方法和dubbo的启动过程(二)--服务方属性配置雷同,这边就不继续了。除了InitializingBean
这个接口,他还继承了FactoryBean
接口,实例化的时候,就会调用getObject
方法,例子看spring学习之FactoryBean,源码见doGetObjectFromFactoryBean。
public Object getObject() {
return get();
}
public synchronized T get() {
// 各种配置的更新
checkAndUpdateSubConfigs();
if (destroyed) {
throw new IllegalStateException("The invoker of ReferenceConfig(" + url + ") has already destroyed!");
}
if (ref == null) {
init();
}
return ref;
}
init
// 以上代码跟服务方雷同,省略
ref = createProxy(map);
String serviceKey = URL.buildKey(interfaceName, group, version);
ApplicationModel.initConsumerModel(serviceKey, buildConsumerModel(serviceKey, attributes));
initialized = true;
创建invoke
在createProxy
方法中,会调用RegistryProtocol
的refer
方法,这里先略过ProtocolFilterWrapper
、ProtocolListenerWrapper
、QosProtocolWrapper
。
public <T> Invoker<T> refer(Class<T> type, URL url) throws RpcException {
// 获取注册中心
url = URLBuilder.from(url)
.setProtocol(url.getParameter(REGISTRY_KEY, DEFAULT_REGISTRY))
.removeParameter(REGISTRY_KEY)
.build();
Registry registry = registryFactory.getRegistry(url);
if (RegistryService.class.equals(type)) {
return proxyFactory.getInvoker((T) registry, type, url);
}
// group="a,b" or group="*"
Map<String, String> qs = StringUtils.parseQueryString(url.getParameterAndDecoded(REFER_KEY));
String group = qs.get(GROUP_KEY);
if (group != null && group.length() > 0) {
if ((COMMA_SPLIT_PATTERN.split(group)).length > 1 || "*".equals(group)) {
return doRefer(getMergeableCluster(), registry, type, url);
}
}
// 关联引用
return doRefer(cluster, registry, type, url);
}
private <T> Invoker<T> doRefer(Cluster cluster, Registry registry, Class<T> type, URL url) {
RegistryDirectory<T> directory = new RegistryDirectory<T>(type, url);
directory.setRegistry(registry);
directory.setProtocol(protocol);
// all attributes of REFER_KEY
Map<String, String> parameters = new HashMap<String, String>(directory.getUrl().getParameters());
// 把消费方信息注册到注册中心
URL subscribeUrl = new URL(CONSUMER_PROTOCOL, parameters.remove(REGISTER_IP_KEY), 0, type.getName(), parameters);
if (!ANY_VALUE.equals(url.getServiceInterface()) && url.getParameter(REGISTER_KEY, true)) {
directory.setRegisteredConsumerUrl(getRegisteredConsumerUrl(subscribeUrl, url));
registry.register(directory.getRegisteredConsumerUrl());
}
directory.buildRouterChain(subscribeUrl);
directory.subscribe(subscribeUrl.addParameter(CATEGORY_KEY,
PROVIDERS_CATEGORY + "," + CONFIGURATORS_CATEGORY + "," + ROUTERS_CATEGORY));
// 获取invoker并缓存
Invoker invoker = cluster.join(directory);
ProviderConsumerRegTable.registerConsumer(invoker, url, subscribeUrl, directory);
return invoker;
}
cluster.join(directory)这个代码,会执行包装类MockClusterWrapper的join方法:
public <T> Invoker<T> join(Directory<T> directory) throws RpcException {
return new MockClusterInvoker<T>(directory,
this.cluster.join(directory));
}
所以invoke是MockClusterInvoker。
创建代理
在createProxy
方法中,invoker创建完了,就开始创建代理,代理类中,通过newInstance的构造参数,把InvokerInvocationHandler传入到成员变量中,后面调用的方法,就是通过这个类的invoke方法进行反射的。
// 调用下面的JavassistProxyFactory的getProxy方法
return (T) PROXY_FACTORY.getProxy(invoker);
// 注意传入的是InvokerInvocationHandler
public <T> T getProxy(Invoker<T> invoker, Class<?>[] interfaces) {
return (T) Proxy.getProxy(interfaces).newInstance(new InvokerInvocationHandler(invoker));
}
执行方法
当执行方法的时候,就会执行InvokerInvocationHandler的invoke方法:
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
String methodName = method.getName();
Class<?>[] parameterTypes = method.getParameterTypes();
// Object直接调用返回
if (method.getDeclaringClass() == Object.class) {
return method.invoke(invoker, args);
}
// toString、hashCode、equals返回响应的invoke方法
if ("toString".equals(methodName) && parameterTypes.length == 0) {
return invoker.toString();
}
if ("hashCode".equals(methodName) && parameterTypes.length == 0) {
return invoker.hashCode();
}
if ("equals".equals(methodName) && parameterTypes.length == 1) {
return invoker.equals(args[0]);
}
// 这个invoke就是MockClusterInvoker,RpcInvocation传入方法参数信息
return invoker.invoke(new RpcInvocation(method, args)).recreate();
}
MockClusterInvoker#invoke
public Result invoke(Invocation invocation) throws RpcException {
Result result = null;
// 是否配置了mock
String value = directory.getUrl().getMethodParameter(invocation.getMethodName(), MOCK_KEY, Boolean.FALSE.toString()).trim();
// 。。。省略部分代码。如果强制调用mock,调用本地的mock
result = doMockInvoke(invocation, null);
// 没有mock,调用FailoverClusterInvoker的方法
result = this.invoker.invoke(invocation);
// 。。。省略
return result;
}
这边会调用FailoverClusterInvoker的父类AbstractClusterInvoker#invoke
public Result invoke(final Invocation invocation) throws RpcException {
// 检查是否被Destroyed
checkWhetherDestroyed();
// binding attachments into invocation.
Map<String, String> contextAttachments = RpcContext.getContext().getAttachments();
if (contextAttachments != null && contextAttachments.size() != 0) {
((RpcInvocation) invocation).addAttachments(contextAttachments);
}
// 获取Invoker列表
List<Invoker<T>> invokers = list(invocation);
// 负载均衡
LoadBalance loadbalance = initLoadBalance(invokers, invocation);
RpcUtils.attachInvocationIdIfAsync(getUrl(), invocation);
// FailoverClusterInvoker#doInvoke
return doInvoke(invocation, invokers, loadbalance);
}
FailoverClusterInvoker#doInvoke
失败重试、负载均衡这里设置
public Result doInvoke(Invocation invocation, final List<Invoker<T>> invokers, LoadBalance loadbalance) throws RpcException {
List<Invoker<T>> copyInvokers = invokers;
// 检查invokers是否为空
checkInvokers(copyInvokers, invocation);
// 获取方法名
String methodName = RpcUtils.getMethodName(invocation);
// 失败重试次数
int len = getUrl().getMethodParameter(methodName, RETRIES_KEY, DEFAULT_RETRIES) + 1;
if (len <= 0) {
len = 1;
}
// retry loop.
// 最后一次exception
RpcException le = null; // last exception.
List<Invoker<T>> invoked = new ArrayList<Invoker<T>>(copyInvokers.size()); // invoked invokers.
Set<String> providers = new HashSet<String>(len);
for (int i = 0; i < len; i++) {
//Reselect before retry to avoid a change of candidate `invokers`.
//NOTE: if `invokers` changed, then `invoked` also lose accuracy.
if (i > 0) {
// 检查是否Destroyed
checkWhetherDestroyed();
// 获取Invokers
copyInvokers = list(invocation);
// check again 检查invokers是否为空
checkInvokers(copyInvokers, invocation);
}
Invoker<T> invoker = select(loadbalance, invocation, copyInvokers, invoked);
invoked.add(invoker);
RpcContext.getContext().setInvokers((List) invoked);
try {
// InvokerWrapper#invoke
Result result = invoker.invoke(invocation);
if (le != null && logger.isWarnEnabled()) {
// 。。。。
}
return result;
} catch (RpcException e) {
if (e.isBiz()) { // biz exception.
throw e;
}
le = e;
} catch (Throwable e) {
le = new RpcException(e.getMessage(), e);
} finally {
providers.add(invoker.getUrl().getAddress());
}
}
// 。。。。
}
InvokerWrapper#invoke:
这个invoker是ProtocolFilterWrapper,在这个invoke中,会调用ProtocolFilterWrapper&CallbackRegistrationInvoker#invoke-->ConsumerContextFilter#invoke-->FutureFilter#invoke-->MonitorFilter#invoke-->ListenerInvokerWrapper#invoke-->AsyncToSyncInvoker#invoke-->DubboInvoker#invoke
public Result invoke(Invocation invocation) throws RpcException {
return invoker.invoke(invocation);
}
ConsumerContextFilter#invoke:
在上下文设置invoker、invocation、LocalAddress、RemoteAddress、RemoteApplicationName、Attachment,再把invoker设置到invocation中,执行完下一个invoke后,再清空上下文信息。
public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
RpcContext.getContext()
.setInvoker(invoker)
.setInvocation(invocation)
.setLocalAddress(NetUtils.getLocalHost(), 0)
.setRemoteAddress(invoker.getUrl().getHost(), invoker.getUrl().getPort())
.setRemoteApplicationName(invoker.getUrl().getParameter(REMOTE_APPLICATION_KEY))
.setAttachment(REMOTE_APPLICATION_KEY, invoker.getUrl().getParameter(APPLICATION_KEY));
if (invocation instanceof RpcInvocation) {
((RpcInvocation) invocation).setInvoker(invoker);
}
try {
RpcContext.removeServerContext();
return invoker.invoke(invocation);
} finally {
RpcContext.removeContext();
}
}
FutureFilter#invoke:
主要是设置回调的
public Result invoke(final Invoker<?> invoker, final Invocation invocation) throws RpcException {
fireInvokeCallback(invoker, invocation);
// need to configure if there's return value before the invocation in order to help invoker to judge if it's
// necessary to return future.
return invoker.invoke(invocation);
}
MonitorFilter#invoke:
接口对应的方法调用的次数。
key为:接口全限定命.方法
value是AtomicInteger类型,记录调用次数
public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
if (invoker.getUrl().hasParameter(MONITOR_KEY)) {
invocation.setAttachment(MONITOR_FILTER_START_TIME, String.valueOf(System.currentTimeMillis()));
getConcurrent(invoker, invocation).incrementAndGet(); // count up
}
return invoker.invoke(invocation); // proceed invocation chain
}
// concurrent counter
private AtomicInteger getConcurrent(Invoker<?> invoker, Invocation invocation) {
String key = invoker.getInterface().getName() + "." + invocation.getMethodName();
AtomicInteger concurrent = concurrents.get(key);
if (concurrent == null) {
concurrents.putIfAbsent(key, new AtomicInteger());
concurrent = concurrents.get(key);
}
return concurrent;
}
ListenerInvokerWrapper#invoke:
直接调用AsyncToSyncInvoker#invoke
public Result invoke(Invocation invocation) throws RpcException {
return invoker.invoke(invocation);
}
AsyncToSyncInvoker#invoke:
如果是同步,就阻塞等待返回,如果是异步,就直接返回
public Result invoke(Invocation invocation) throws RpcException {
Result asyncResult = invoker.invoke(invocation);
try {
// 同步就阻塞等待返回
if (InvokeMode.SYNC == ((RpcInvocation) invocation).getInvokeMode()) {
asyncResult.get(Integer.MAX_VALUE, TimeUnit.MILLISECONDS);
}
} catch (InterruptedException e) {
throw new RpcException("Interrupted unexpectedly while waiting for remoting result to return! method: " + invocation.getMethodName() + ", provider: " + getUrl() + ", cause: " + e.getMessage(), e);
} catch (ExecutionException e) {
Throwable t = e.getCause();
if (t instanceof TimeoutException) {
throw new RpcException(RpcException.TIMEOUT_EXCEPTION, "Invoke remote method timeout. method: " + invocation.getMethodName() + ", provider: " + getUrl() + ", cause: " + e.getMessage(), e);
} else if (t instanceof RemotingException) {
throw new RpcException(RpcException.NETWORK_EXCEPTION, "Failed to invoke remote method: " + invocation.getMethodName() + ", provider: " + getUrl() + ", cause: " + e.getMessage(), e);
}
} catch (Throwable e) {
throw new RpcException(e.getMessage(), e);
}
return asyncResult;
}
AbstractInvoker#invoke
public Result invoke(Invocation inv) throws RpcException {
// if invoker is destroyed due to address refresh from registry, let's allow the current invoke to proceed
if (destroyed.get()) {
logger.warn("Invoker for service " + this + " on consumer " + NetUtils.getLocalHost() + " is destroyed, "
+ ", dubbo version is " + Version.getVersion() + ", this invoker should not be used any longer");
}
RpcInvocation invocation = (RpcInvocation) inv;
// 传入当前的dubboInvoker
invocation.setInvoker(this);
if (CollectionUtils.isNotEmptyMap(attachment)) {
invocation.addAttachmentsIfAbsent(attachment);
}
Map<String, String> contextAttachments = RpcContext.getContext().getAttachments();
if (CollectionUtils.isNotEmptyMap(contextAttachments)) {
invocation.addAttachments(contextAttachments);
}
// 包括FUTURE、ASYNC、SYNC
invocation.setInvokeMode(RpcUtils.getInvokeMode(url, invocation));
// Async时设置ID
RpcUtils.attachInvocationIdIfAsync(getUrl(), invocation);
try {
return doInvoke(invocation);
} catch (InvocationTargetException e) { // biz exception
Throwable te = e.getTargetException();
if (te == null) {
return AsyncRpcResult.newDefaultAsyncResult(null, e, invocation);
} else {
if (te instanceof RpcException) {
((RpcException) te).setCode(RpcException.BIZ_EXCEPTION);
}
return AsyncRpcResult.newDefaultAsyncResult(null, te, invocation);
}
} catch (RpcException e) {
if (e.isBiz()) {
return AsyncRpcResult.newDefaultAsyncResult(null, e, invocation);
} else {
throw e;
}
} catch (Throwable e) {
return AsyncRpcResult.newDefaultAsyncResult(null, e, invocation);
}
}
DubboInvoker#doInvoke
远程调用接口,获取数据
protected Result doInvoke(final Invocation invocation) throws Throwable {
// 给inv设置路径和版本信息
RpcInvocation inv = (RpcInvocation) invocation;
final String methodName = RpcUtils.getMethodName(invocation);
inv.setAttachment(PATH_KEY, getUrl().getPath());
inv.setAttachment(VERSION_KEY, version);
// 获取一个ExchangeClient
ExchangeClient currentClient;
if (clients.length == 1) {
currentClient = clients[0];
} else {
currentClient = clients[index.getAndIncrement() % clients.length];
}
try {
// 是否为Oneway
boolean isOneway = RpcUtils.isOneway(getUrl(), invocation);
int timeout = getUrl().getMethodPositiveParameter(methodName, TIMEOUT_KEY, DEFAULT_TIMEOUT);
if (isOneway) {
boolean isSent = getUrl().getMethodParameter(methodName, Constants.SENT_KEY, false);
currentClient.send(inv, isSent);
return AsyncRpcResult.newDefaultAsyncResult(invocation);
} else {
AsyncRpcResult asyncRpcResult = new AsyncRpcResult(inv);
CompletableFuture<Object> responseFuture = currentClient.request(inv, timeout);
asyncRpcResult.subscribeTo(responseFuture);
// save for 2.6.x compatibility, for example, TraceFilter in Zipkin uses com.alibaba.xxx.FutureAdapter
FutureContext.getContext().setCompatibleFuture(responseFuture);
return asyncRpcResult;
}
} catch (TimeoutException e) {
throw new RpcException(RpcException.TIMEOUT_EXCEPTION, "Invoke remote method timeout. method: " + invocation.getMethodName() + ", provider: " + getUrl() + ", cause: " + e.getMessage(), e);
} catch (RemotingException e) {
throw new RpcException(RpcException.NETWORK_EXCEPTION, "Failed to invoke remote method: " + invocation.getMethodName() + ", provider: " + getUrl() + ", cause: " + e.getMessage(), e);
}
}
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