- Author: HuiFer
- 源码阅读仓库: SourceHot-Spring
- Spring 远程服务调用
DEMO
服务提供方
- 服务提供方需要准备接口、接口实现泪
- 接口
public interface IDemoRmiService { int add(int a, int b); }
- 接口实现
public class IDemoRmiServiceImpl implements IDemoRmiService { @Override public int add(int a, int b) { return a + b; } }
- xml 配置文件
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.springframework.org/schema/beans" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <bean id="demoRmiService" class="com.huifer.source.spring.rmi.impl.IDemoRmiServiceImpl"/> <bean id="demoRmi" class="org.springframework.remoting.rmi.RmiServiceExporter"> <!-- 服务--> <property name="service" ref="demoRmiService"/> <!-- 服务名称--> <property name="serviceName" value="springRmi"/> <!-- 服务接口--> <property name="serviceInterface" value="com.huifer.source.spring.rmi.IDemoRmiService"/> <!-- 注册端口--> <property name="registryPort" value="9999"/> </bean> </beans>
- 运行
public class RMIServerSourceCode { public static void main(String[] args) throws Exception { ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("rmi/RMISourceCode.xml"); } }
服务调用方
- xml 配置
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <bean id="rmiClient" class="org.springframework.remoting.rmi.RmiProxyFactoryBean"> <property name="serviceUrl" value="rmi://localhost:9999/springRmi"/> <property name="serviceInterface" value="com.huifer.source.spring.rmi.IDemoRmiService"/> </bean> </beans>
注意:rmi 使用小写 大写报错信息:
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'rmiClient' defined in class path resource [rmi/RMIClientSourceCode.xml]: Invocation of init method failed; nested exception is org.springframework.remoting.RemoteLookupFailureException: Service URL [RMI://localhost:9999/springRmi] is invalid; nested exception is java.net.MalformedURLException: invalid URL scheme: RMI://localhost:9999/springRmi
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1795)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:559)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:478)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:309)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:272)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:176)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:877)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:953)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:579)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:163)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:90)
at com.huifer.source.spring.rmi.RMIClientSourceCode.main(RMIClientSourceCode.java:7)
Caused by: org.springframework.remoting.RemoteLookupFailureException: Service URL [RMI://localhost:9999/springRmi] is invalid; nested exception is java.net.MalformedURLException: invalid URL scheme: RMI://localhost:9999/springRmi
at org.springframework.remoting.rmi.RmiClientInterceptor.lookupStub(RmiClientInterceptor.java:209)
at org.springframework.remoting.rmi.RmiClientInterceptor.prepare(RmiClientInterceptor.java:147)
at org.springframework.remoting.rmi.RmiClientInterceptor.afterPropertiesSet(RmiClientInterceptor.java:134)
at org.springframework.remoting.rmi.RmiProxyFactoryBean.afterPropertiesSet(RmiProxyFactoryBean.java:68)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1868)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1791)
... 12 more
Caused by: java.net.MalformedURLException: invalid URL scheme: RMI://localhost:9999/springRmi
at java.rmi.Naming.intParseURL(Naming.java:290)
at java.rmi.Naming.parseURL(Naming.java:237)
at java.rmi.Naming.lookup(Naming.java:96)
at org.springframework.remoting.rmi.RmiClientInterceptor.lookupStub(RmiClientInterceptor.java:201)
... 17 more
- 运行
public class RMIClientSourceCode { public static void main(String[] args) { ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("rmi/RMIClientSourceCode.xml"); IDemoRmiService rmiClient = context.getBean("rmiClient", IDemoRmiService.class); int add = rmiClient.add(1, 2); System.out.println(add); } }
服务端初始化
org.springframework.remoting.rmi.RmiServiceExporter,该类定义了 spring 的远程服务信息
RmiServiceExporter
- 基础属性如下
public class RmiServiceExporter extends RmiBasedExporter implements InitializingBean, DisposableBean { /** * 服务名称,rmi的服务名,在Spring中使用ref指向impl实现类 */ private String serviceName; /** * */ private int servicePort = 0; // anonymous port private RMIClientSocketFactory clientSocketFactory; private RMIServerSocketFactory serverSocketFactory; private Registry registry; /** * 注册的IP地址 */ private String registryHost; /** * 注册的端口 */ private int registryPort = Registry.REGISTRY_PORT; /** * 进行远程对象调用的Socket工厂 */ private RMIClientSocketFactory clientSocketFactory; /** * 接收远程调用服务端的Socket工厂 */ private RMIServerSocketFactory serverSocketFactory; /** * true: 该参数在获取{@link Registry}时测试是否建立连接,如果建立连接则直接使用,否则创建新连接 * 是否总是创建{@link Registry} */ private boolean alwaysCreateRegistry = false; /** * 设置替换RMI注册表中的绑定关系 */ private boolean replaceExistingBinding = true; private Remote exportedObject; /** * 创建{@link Registry} */ private boolean createdRegistry = false; }
- 属性设置不说了,看接口实现了那些
- InitializingBean: 初始化 bean 调用
afterPropertiesSet方法 - DisposableBean: 摧毁 bean 调用
destroy方法
- InitializingBean: 初始化 bean 调用
@Override public void afterPropertiesSet() throws RemoteException { prepare(); } public void prepare() throws RemoteException { // 校验service checkService(); // 服务名称校验 if (this.serviceName == null) { throw new IllegalArgumentException("Property 'serviceName' is required"); } // Check socket factories for exported object. if (this.clientSocketFactory instanceof RMIServerSocketFactory) { this.serverSocketFactory = (RMIServerSocketFactory) this.clientSocketFactory; } if ((this.clientSocketFactory != null && this.serverSocketFactory == null) || (this.clientSocketFactory == null && this.serverSocketFactory != null)) { throw new IllegalArgumentException( "Both RMIClientSocketFactory and RMIServerSocketFactory or none required"); } // Check socket factories for RMI registry. if (this.registryClientSocketFactory instanceof RMIServerSocketFactory) { this.registryServerSocketFactory = (RMIServerSocketFactory) this.registryClientSocketFactory; } if (this.registryClientSocketFactory == null && this.registryServerSocketFactory != null) { throw new IllegalArgumentException( "RMIServerSocketFactory without RMIClientSocketFactory for registry not supported"); } this.createdRegistry = false; // Determine RMI registry to use. if (this.registry == null) { // registry 获取 this.registry = getRegistry(this.registryHost, this.registryPort, this.registryClientSocketFactory, this.registryServerSocketFactory); this.createdRegistry = true; } // Initialize and cache exported object. // 初始化并且获取缓存的object this.exportedObject = getObjectToExport(); if (logger.isDebugEnabled()) { logger.debug("Binding service '" + this.serviceName + "' to RMI registry: " + this.registry); } // Export RMI object. // 导出RMI object if (this.clientSocketFactory != null) { UnicastRemoteObject.exportObject( this.exportedObject, this.servicePort, this.clientSocketFactory, this.serverSocketFactory); } else { UnicastRemoteObject.exportObject(this.exportedObject, this.servicePort); } // Bind RMI object to registry. // 对象绑定,把serviceName 和 到处的RMI对象进行绑定,JDK实现 try { if (this.replaceExistingBinding) { this.registry.rebind(this.serviceName, this.exportedObject); } else { this.registry.bind(this.serviceName, this.exportedObject); } } catch (AlreadyBoundException ex) { // Already an RMI object bound for the specified service name... unexportObjectSilently(); throw new IllegalStateException( "Already an RMI object bound for name '" + this.serviceName + "': " + ex.toString()); } catch (RemoteException ex) { // Registry binding failed: let's unexport the RMI object as well. unexportObjectSilently(); throw ex; } }
checkService
- 校验 service 是否为空
/** * Check whether the service reference has been set. * * 校验service * @see #setService */ protected void checkService() throws IllegalArgumentException { Assert.notNull(getService(), "Property 'service' is required"); }
getRegistry
- 获取 Registry 实例
- 简单说就是通过 host 和 port 创建 socket
protected Registry getRegistry(String registryHost, int registryPort, @Nullable RMIClientSocketFactory clientSocketFactory, @Nullable RMIServerSocketFactory serverSocketFactory) throws RemoteException { if (registryHost != null) { // Host explicitly specified: only lookup possible. if (logger.isDebugEnabled()) { logger.debug("Looking for RMI registry at port '" + registryPort + "' of host [" + registryHost + "]"); } // 通过 host port socket创建 Registry reg = LocateRegistry.getRegistry(registryHost, registryPort, clientSocketFactory); testRegistry(reg); return reg; } else { return getRegistry(registryPort, clientSocketFactory, serverSocketFactory); } }
getObjectToExport
- 初始化并且获取缓存的 object
protected Remote getObjectToExport() { // determine remote object if (getService() instanceof Remote && (getServiceInterface() == null || Remote.class.isAssignableFrom(getServiceInterface()))) { // conventional RMI service // 获取service return (Remote) getService(); } else { // RMI invoker if (logger.isDebugEnabled()) { logger.debug("RMI service [" + getService() + "] is an RMI invoker"); } // RMI 包装类 /** * 1. getProxyForService() 获取代理的接口 * 2. 创建RMI包装对象 RmiInvocationWrapper */ return new RmiInvocationWrapper(getProxyForService(), this); } }
getProxyForService
- 获取代理服务
protected Object getProxyForService() { // service 校验 checkService(); // 校验接口 checkServiceInterface(); // 代理工厂 ProxyFactory proxyFactory = new ProxyFactory(); // 添加代理接口 proxyFactory.addInterface(getServiceInterface()); if (this.registerTraceInterceptor != null ? this.registerTraceInterceptor : this.interceptors == null) { // 添加切面 proxyFactory.addAdvice(new RemoteInvocationTraceInterceptor(getExporterName())); } if (this.interceptors != null) { AdvisorAdapterRegistry adapterRegistry = GlobalAdvisorAdapterRegistry.getInstance(); for (Object interceptor : this.interceptors) { proxyFactory.addAdvisor(adapterRegistry.wrap(interceptor)); } } // 设置代理类 proxyFactory.setTarget(getService()); proxyFactory.setOpaque(true); // 获取代理对象 return proxyFactory.getProxy(getBeanClassLoader()); }
- 这里要注意,切片方法的
invoke调用 RmiInvocationWrapper的invoke方法会在调用方调用接口时候触发
rebind 和 bind
- 绑定和重新绑定
- 这部分源码在:
sun.rmi.registry.RegistryImpl
public void rebind(String var1, Remote var2) throws RemoteException, AccessException { checkAccess("Registry.rebind"); this.bindings.put(var1, var2); }
public void bind(String var1, Remote var2) throws RemoteException, AlreadyBoundException, AccessException { checkAccess("Registry.bind"); synchronized(this.bindings) { Remote var4 = (Remote)this.bindings.get(var1); if (var4 != null) { throw new AlreadyBoundException(var1); } else { this.bindings.put(var1, var2); } } }
- 共同维护
private Hashtable<String, Remote> bindings = new Hashtable(101);这个对象
unexportObjectSilently
- 出现异常时候调用方法
private void unexportObjectSilently() { try { UnicastRemoteObject.unexportObject(this.exportedObject, true); } catch (NoSuchObjectException ex) { if (logger.isInfoEnabled()) { logger.info("RMI object for service '" + this.serviceName + "' is not exported anymore", ex); } } }
客户端初始化
RmiProxyFactoryBean
-
该类实现了
InitializingBean接口直接看afterPropertiesSet方法 -
org.springframework.remoting.rmi.RmiProxyFactoryBean-
@Override public void afterPropertiesSet() { super.afterPropertiesSet(); Class<?> ifc = getServiceInterface(); Assert.notNull(ifc, "Property 'serviceInterface' is required"); this.serviceProxy = new ProxyFactory(ifc, this).getProxy(getBeanClassLoader()); }
-
org.springframework.remoting.rmi.RmiClientInterceptor#afterPropertiesSet-
@Override public void afterPropertiesSet() { super.afterPropertiesSet(); prepare(); }
-
org.springframework.remoting.support.UrlBasedRemoteAccessor#afterPropertiesSet-
@Override public void afterPropertiesSet() { if (getServiceUrl() == null) { throw new IllegalArgumentException("Property 'serviceUrl' is required"); } }
-
-
-
org.springframework.remoting.support.UrlBasedRemoteAccessor#afterPropertiesSet
- 该方法对
serviceUrl进行空判断,如果是空的抛出异常
/** * 判断服务地址是否为空 */ @Override public void afterPropertiesSet() { if (getServiceUrl() == null) { throw new IllegalArgumentException("Property 'serviceUrl' is required"); } }
org.springframework.remoting.rmi.RmiClientInterceptor#afterPropertiesSet
@Override public void afterPropertiesSet() { super.afterPropertiesSet(); prepare(); }
- 调用父类的
afterPropertiesSet方法判断serviceUrl是否为空 - 执行
prepare()方法
public void prepare() throws RemoteLookupFailureException { // Cache RMI stub on initialization? if (this.lookupStubOnStartup) { // 获取remote对象 Remote remoteObj = lookupStub(); if (logger.isDebugEnabled()) { if (remoteObj instanceof RmiInvocationHandler) { logger.debug("RMI stub [" + getServiceUrl() + "] is an RMI invoker"); } else if (getServiceInterface() != null) { // 是否接口 boolean isImpl = getServiceInterface().isInstance(remoteObj); logger.debug("Using service interface [" + getServiceInterface().getName() + "] for RMI stub [" + getServiceUrl() + "] - " + (!isImpl ? "not " : "") + "directly implemented"); } } if (this.cacheStub) { this.cachedStub = remoteObj; } } }
org.springframework.remoting.rmi.RmiClientInterceptor#lookupStub
protected Remote lookupStub() throws RemoteLookupFailureException { try { Remote stub = null; if (this.registryClientSocketFactory != null) { // RMIClientSocketFactory specified for registry access. // Unfortunately, due to RMI API limitations, this means // that we need to parse the RMI URL ourselves and perform // straight LocateRegistry.getRegistry/Registry.lookup calls. // 通过 serviceUrl 创建 URL URL url = new URL(null, getServiceUrl(), new DummyURLStreamHandler()); // url 的协议 String protocol = url.getProtocol(); if (protocol != null && !"rmi".equals(protocol)) { throw new MalformedURLException("Invalid URL scheme '" + protocol + "'"); } // 获取host String host = url.getHost(); // 获取port int port = url.getPort(); // 获取serviceName String name = url.getPath(); if (name != null && name.startsWith("/")) { name = name.substring(1); } // 创建 Registry Registry registry = LocateRegistry.getRegistry(host, port, this.registryClientSocketFactory); // 获取Remote stub = registry.lookup(name); } else { // Can proceed with standard RMI lookup API... stub = Naming.lookup(getServiceUrl()); } if (logger.isDebugEnabled()) { logger.debug("Located RMI stub with URL [" + getServiceUrl() + "]"); } return stub; } catch (MalformedURLException ex) { throw new RemoteLookupFailureException("Service URL [" + getServiceUrl() + "] is invalid", ex); } catch (NotBoundException ex) { throw new RemoteLookupFailureException( "Could not find RMI service [" + getServiceUrl() + "] in RMI registry", ex); } catch (RemoteException ex) { throw new RemoteLookupFailureException("Lookup of RMI stub failed", ex); } }
org.springframework.remoting.rmi.RmiProxyFactoryBean#afterPropertiesSet
@Override public void afterPropertiesSet() { super.afterPropertiesSet(); // 获取 服务提供的接口 Class<?> ifc = getServiceInterface(); // 如果服务接口不为空 Assert.notNull(ifc, "Property 'serviceInterface' is required"); // 创建服务代理 this.serviceProxy = new ProxyFactory(ifc, this).getProxy(getBeanClassLoader()); }
增强调用
- 通过类图我们可以知道
RmiProxyFactoryBean实现了MethodInterceptor,具体实现方法在org.springframework.remoting.rmi.RmiClientInterceptor#invoke
@Override public Object invoke(MethodInvocation invocation) throws Throwable { // 获取remote Remote stub = getStub(); try { // 真正的invoke调用 return doInvoke(invocation, stub); } catch (RemoteConnectFailureException ex) { return handleRemoteConnectFailure(invocation, ex); } catch (RemoteException ex) { if (isConnectFailure(ex)) { return handleRemoteConnectFailure(invocation, ex); } else { throw ex; } } }
protected Remote getStub() throws RemoteLookupFailureException { if (!this.cacheStub || (this.lookupStubOnStartup && !this.refreshStubOnConnectFailure)) { // 如果缓存stub存在直接获取,否则创建 return (this.cachedStub != null ? this.cachedStub : lookupStub()); } else { synchronized (this.stubMonitor) { if (this.cachedStub == null) { this.cachedStub = lookupStub(); } return this.cachedStub; } } }
org.springframework.remoting.rmi.RmiClientInterceptor#doInvoke(org.aopalliance.intercept.MethodInvocation, org.springframework.remoting.rmi.RmiInvocationHandler)
@Nullable protected Object doInvoke(MethodInvocation methodInvocation, RmiInvocationHandler invocationHandler) throws RemoteException, NoSuchMethodException, IllegalAccessException, InvocationTargetException { if (AopUtils.isToStringMethod(methodInvocation.getMethod())) { return "RMI invoker proxy for service URL [" + getServiceUrl() + "]"; } /** * 1. 参数组装成对象{@link RemoteInvocationBasedAccessor#createRemoteInvocation(org.aopalliance.intercept.MethodInvocation)} * 2. invoke 执行 简单来说就是调用{@link RmiInvocationHandler#invoke(RemoteInvocation)}方法 */ return invocationHandler.invoke(createRemoteInvocation(methodInvocation)); }
RmiInvocationHandler类图
最后的invoke方法
-
org.springframework.remoting.rmi.RmiInvocationWrapper#invoke/** * Delegates the actual invocation handling to the RMI exporter. * * * 远程调用的时候会执行 * @see RmiBasedExporter#invoke(org.springframework.remoting.support.RemoteInvocation, Object) */ @Override @Nullable public Object invoke(RemoteInvocation invocation) throws RemoteException, NoSuchMethodException, IllegalAccessException, InvocationTargetException { return this.rmiExporter.invoke(invocation, this.wrappedObject); }
-
继续跟踪
org.springframework.remoting.rmi.RmiBasedExporter#invoke@Override protected Object invoke(RemoteInvocation invocation, Object targetObject) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException { return super.invoke(invocation, targetObject); }
-
继续跟踪
org.springframework.remoting.support.RemoteInvocationBasedExporter#invokeprotected Object invoke(RemoteInvocation invocation, Object targetObject) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException { if (logger.isTraceEnabled()) { logger.trace("Executing " + invocation); } try { return getRemoteInvocationExecutor().invoke(invocation, targetObject); } catch (NoSuchMethodException ex) { if (logger.isDebugEnabled()) { logger.debug("Could not find target method for " + invocation, ex); } throw ex; } catch (IllegalAccessException ex) { if (logger.isDebugEnabled()) { logger.debug("Could not access target method for " + invocation, ex); } throw ex; } catch (InvocationTargetException ex) { if (logger.isDebugEnabled()) { logger.debug("Target method failed for " + invocation, ex.getTargetException()); } throw ex; } }
-
-
-
关键语句**
return getRemoteInvocationExecutor().invoke(invocation, targetObject);**
类图
public class DefaultRemoteInvocationExecutor implements RemoteInvocationExecutor { @Override public Object invoke(RemoteInvocation invocation, Object targetObject) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException { Assert.notNull(invocation, "RemoteInvocation must not be null"); Assert.notNull(targetObject, "Target object must not be null"); return invocation.invoke(targetObject); } }
public Object invoke(Object targetObject) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException { Method method = targetObject.getClass().getMethod(this.methodName, this.parameterTypes); return method.invoke(targetObject, this.arguments); }
- 这部分流程相对清晰,从对象中获取函数,调用这个函数
服务端 debug
org.springframework.remoting.rmi.RmiServiceExporter#afterPropertiesSet打上断点
可以看到此时的数据字段和我们的 xml 配置中一致
-
org.springframework.remoting.rmi.RmiServiceExporter#prepare断点往下一直走
这一行是 jdk 的就不进去看了
执行完成就创建出了
Registry -
org.springframework.remoting.rmi.RmiBasedExporter#getObjectToExport直接看结果对象
-
执行 bind
-
此时服务端信息已经成功记录并且启动
客户端 debug
remote 对象
- 服务提供接口
stub 对象



















