基于Netty4手把手实现一个带注册中心和注解的Dubbo框架
阅读这篇文章之前，建议先阅读和这篇文章关联的内容。
1. 详细剖析分布式微服务架构下网络通信的底层实现原理（图解）
2. (年薪60W的技巧)工作了5年，你真的理解Netty以及为什么要用吗？（深度干货）
4. BAT面试必问细节：关于Netty中的ByteBuf详解
5. 通过大量实战案例分解Netty中是如何解决拆包黏包问题的?
6. 基于Netty实现自定义消息通信协议（协议设计及解析应用实战）
8. 手把手教你基于Netty实现一个基础的RPC框架（通俗易懂）
在本篇文章中，我们继续围绕Netty手写实现RPC基础篇进行优化，主要引入几个点
- 集成spring，实现注解驱动配置
- 集成zookeeper，实现服务注册
- 增加负载均衡实现
源代码，加「跟着Mic学架构」微信号，回复『rpc』获取。
增加注解驱动
主要涉及到的修改模块
- netty-rpc-protocol
- netty-rpc-provider
netty-rpc-protocol
当前模块主要修改的类如下。
图7-1
下面针对netty-rpc-protocol模块的修改如下
这个注解的作用是用来指定某些服务为远程服务
@Target(ElementType.TYPE)// Target说明了Annotation所修饰的对象范围, TYPE:用于描述类、接口(包括注解类型) 或enum声明
@Retention(RetentionPolicy.RUNTIME)// Reteniton的作用是定义被它所注解的注解保留多久，保留至运行时。所以我们可以通过反射去获取注解信息。
@Component
public @interface GpRemoteService {
}这个类主要用来在启动NettyServer，以及保存bean的映射关系
@Slf4j
public class SpringRpcProviderBean implements InitializingBean, BeanPostProcessor {
private final int serverPort;
private final String serverAddress;
public SpringRpcProviderBean(int serverPort) throws UnknownHostException {
this.serverPort = serverPort;
InetAddress address=InetAddress.getLocalHost();
this.serverAddress=address.getHostAddress();
}
@Override
public void afterPropertiesSet() throws Exception {
log.info("begin deploy Netty Server to host {},on port {}",this.serverAddress,this.serverPort);
new Thread(()->{
try {
new NettyServer(this.serverAddress,this.serverPort).startNettyServer();
} catch (Exception e) {
log.error("start Netty Server Occur Exception,",e);
e.printStackTrace();
}
}).start();
}
//bean实例化后调用
@Override
public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
if(bean.getClass().isAnnotationPresent(GpRemoteService.class)){ //针对存在该注解的服务进行发布
Method[] methods=bean.getClass().getDeclaredMethods();
for(Method method: methods){ //保存需要发布的bean的映射
String key=bean.getClass().getInterfaces()[0].getName()+"."+method.getName();
BeanMethod beanMethod=new BeanMethod();
beanMethod.setBean(bean);
beanMethod.setMethod(method);
Mediator.beanMethodMap.put(key,beanMethod);
}
}
return bean;
}
}主要管理bean以及调用
BeanMethod
@Data
public class BeanMethod {
private Object bean;
private Method method;
}Mediator
负责持有发布bean的管理，以及bean的反射调用
public class Mediator {
public static Map<String,BeanMethod> beanMethodMap=new ConcurrentHashMap<>();
private volatile static Mediator instance=null;
private Mediator(){
}
public static Mediator getInstance(){
if(instance==null){
synchronized (Mediator.class){
if(instance==null){
instance=new Mediator();
}
}
}
return instance;
}
public Object processor(RpcRequest rpcRequest){
String key=rpcRequest.getClassName()+"."+rpcRequest.getMethodName();
BeanMethod beanMethod=beanMethodMap.get(key);
if(beanMethod==null){
return null;
}
Object bean=beanMethod.getBean();
Method method=beanMethod.getMethod();
try {
return method.invoke(bean,rpcRequest.getParams());
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
return null;
}
}定义配置属性
@Data
@ConfigurationProperties(prefix = "gp.rpc")
public class RpcServerProperties {
private int servicePort;
}定义自动配置类
@Configuration
@EnableConfigurationProperties(RpcServerProperties.class)
public class RpcProviderAutoConfiguration {
@Bean
public SpringRpcProviderBean rpcProviderBean(RpcServerProperties rpcServerProperties) throws UnknownHostException {
return new SpringRpcProviderBean(rpcServerProperties.getServicePort());
}
}修改调用方式，直接使用Mediator的调用即可。
public class RpcServerHandler extends SimpleChannelInboundHandler<RpcProtocol<RpcRequest>> {
@Override
protected void channelRead0(ChannelHandlerContext ctx, RpcProtocol<RpcRequest> msg) throws Exception {
RpcProtocol resProtocol=new RpcProtocol<>();
Header header=msg.getHeader();
header.setReqType(ReqType.RESPONSE.code());
Object result=Mediator.getInstance().processor(msg.getContent()); //主要修改这个部分
resProtocol.setHeader(header);
RpcResponse response=new RpcResponse();
response.setData(result);
response.setMsg("success");
resProtocol.setContent(response);
ctx.writeAndFlush(resProtocol);
}
}netty-rpc-provider
这个模块中主要修改两个部分
application.properties
NettyRpcProviderMain
@ComponentScan(basePackages = {"com.example.spring.annotation","com.example.spring.service","com.example.service"})
@SpringBootApplication
public class NettyRpcProviderMain {public static void main(String[] args) throws Exception { SpringApplication.run(NettyRpcProviderMain.class, args); //去掉原来的实例化部分 }}
增加一个配置属性。
gp.rpc.servicePort=20880把当前服务发布出去。
@GpRemoteService //表示将当前服务发布成远程服务
@Slf4j
public class UserServiceImpl implements IUserService {
@Override
public String saveUser(String name) {
log.info("begin saveUser:"+name);
return "Save User Success!";
}
}修改客户端的注解驱动
客户端同样也需要通过注解的方式来引用服务，这样就能够彻底的屏蔽掉远程通信的细节内容，代码结构如图7-2所示
图7-2
在netty-rpc-protocol模块的annotation目录下创建下面这个注解。
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
@Autowired
public @interface GpRemoteReference {
}定义工厂Bean，用来构建远程通信的代理
public class SpringRpcReferenceBean implements FactoryBean<Object> {
private Class<?> interfaceClass;
private Object object;
private String serviceAddress;
private int servicePort;
@Override
public Object getObject() throws Exception {
return object;
}
public void init(){
this.object= Proxy.newProxyInstance(this.interfaceClass.getClassLoader(),
new Class<?>[]{this.interfaceClass},
new RpcInvokerProxy(this.serviceAddress,this.servicePort));
}
@Override
public Class<?> getObjectType() {
return this.interfaceClass;
}
public void setInterfaceClass(Class<?> interfaceClass) {
this.interfaceClass = interfaceClass;
}
public void setServiceAddress(String serviceAddress) {
this.serviceAddress = serviceAddress;
}
public void setServicePort(int servicePort) {
this.servicePort = servicePort;
}
}用来实现远程Bean的动态代理注入：
BeanClassLoaderAware： 获取Bean的类装载器
BeanFactoryPostProcessor：在spring容器加载了bean的定义文件之后，在bean实例化之前执行
ApplicationContextAware： 获取上下文对象ApplicationContenxt
@Slf4j
public class SpringRpcReferencePostProcessor implements ApplicationContextAware, BeanClassLoaderAware, BeanFactoryPostProcessor {
private ApplicationContext context;
private ClassLoader classLoader;
private RpcClientProperties clientProperties;public SpringRpcReferencePostProcessor(RpcClientProperties clientProperties) { this.clientProperties = clientProperties; } //保存发布的引用bean信息 private final Map<String, BeanDefinition> rpcRefBeanDefinitions=new ConcurrentHashMap<>(); @Override public void setBeanClassLoader(ClassLoader classLoader) { this.classLoader=classLoader; } @Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { this.context=applicationContext; } @Override public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException { for (String beanDefinitionname:beanFactory.getBeanDefinitionNames()){ //遍历bean定义，然后获取到加载的bean，遍历这些bean中的字段，是否携带GpRemoteReference注解 //如果有，则需要构建一个动态代理实现 BeanDefinition beanDefinition=beanFactory.getBeanDefinition(beanDefinitionname); String beanClassName=beanDefinition.getBeanClassName(); if(beanClassName!=null){ //和forName方法相同，内部就是直接调用的forName方法 Class<?> clazz=ClassUtils.resolveClassName(beanClassName,this.classLoader); //针对当前类中的指定字段，动态创建一个Bean ReflectionUtils.doWithFields(clazz,this::parseRpcReference); } } //将@GpRemoteReference注解的bean，构建一个动态代理对象 BeanDefinitionRegistry registry=(BeanDefinitionRegistry)beanFactory; this.rpcRefBeanDefinitions.forEach((beanName,beanDefinition)->{ if(context.containsBean(beanName)){ log.warn("SpringContext already register bean {}",beanName); return; } //把动态创建的bean注册到容器中 registry.registerBeanDefinition(beanName,beanDefinition); log.info("registered RpcReferenceBean {} success.",beanName); }); } private void parseRpcReference(Field field){ GpRemoteReference gpRemoteReference=AnnotationUtils.getAnnotation(field,GpRemoteReference.class); if(gpRemoteReference!=null) { BeanDefinitionBuilder builder=BeanDefinitionBuilder.genericBeanDefinition(SpringRpcReferenceBean.class); builder.setInitMethodName(RpcConstant.INIT_METHOD_NAME); builder.addPropertyValue("interfaceClass",field.getType()); builder.addPropertyValue("serviceAddress",clientProperties.getServiceAddress()); builder.addPropertyValue("servicePort",clientProperties.getServicePort()); BeanDefinition beanDefinition=builder.getBeanDefinition(); rpcRefBeanDefinitions.put(field.getName(),beanDefinition); } }}
需要在RpcConstant常量中增加一个INIT_METHOD_NAME属性
public class RpcConstant {
//header部分的总字节数
public final static int HEAD_TOTAL_LEN=16;
//魔数
public final static short MAGIC=0xca;
public static final String INIT_METHOD_NAME = "init";
}
@Data
public class RpcClientProperties {
private String serviceAddress="192.168.1.102";
private int servicePort=20880;
}
@Configuration
public class RpcRefernceAutoConfiguration implements EnvironmentAware{
@Bean
public SpringRpcReferencePostProcessor postProcessor(){
String address=environment.getProperty("gp.serviceAddress");
int port=Integer.parseInt(environment.getProperty("gp.servicePort"));
RpcClientProperties rc=new RpcClientProperties();
rc.setServiceAddress(address);
rc.setServicePort(port);
return new SpringRpcReferencePostProcessor(rc);
}
private Environment environment;
@Override
public void setEnvironment(Environment environment) {
this.environment=environment;
}
}netty-rpc-consumer
修改netty-rpc-consumer模块
- 把该模块变成一个spring boot项目
- 增加web依赖
- 添加测试类
图7-3 netty-rpc-consumer模块
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
@RestController
public class HelloController {
@GpRemoteReference
private IUserService userService;
@GetMapping("/test")
public String test(){
return userService.saveUser("Mic");
}
}
@ComponentScan(basePackages = {"com.example.spring.annotation","com.example.controller","com.example.spring.reference"})
@SpringBootApplication
public class NettyConsumerMain {
public static void main(String[] args) {
SpringApplication.run(NettyConsumerMain.class, args);
}
}
gp.serviceAddress=192.168.1.102
servicePort.servicePort=20880- 启动Netty-Rpc-Server
- 启动Netty-Rpc-Consumer
如果启动过程没有任何问题，则可以访问HelloController来测试远程服务的访问。
引入注册中心
创建一个netty-rpc-registry模块，代码结构如图7-4所示。
引入相关依赖
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-framework</artifactId>
<version>4.2.0</version>
</dependency>
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-recipes</artifactId>
<version>4.2.0</version>
</dependency>
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-x-discovery</artifactId>
<version>4.2.0</version>
</dependency>
public interface IRegistryService {
/**
* 注册服务
* @param serviceInfo
* @throws Exception
*/
void register(ServiceInfo serviceInfo) throws Exception;
/**
* 取消注册
* @param serviceInfo
* @throws Exception
*/
void unRegister(ServiceInfo serviceInfo) throws Exception;
/**
* 动态发现服务
* @param serviceName
* @return
* @throws Exception
*/
ServiceInfo discovery(String serviceName) throws Exception;
}
@Data
public class ServiceInfo {
private String serviceName;
private String serviceAddress;
private int servicePort;
}
@Slf4j
public class ZookeeperRegistryService implements IRegistryService {
private static final String REGISTRY_PATH="/registry";
//Curator中提供的服务注册与发现的组件封装，它对此抽象出了ServiceInstance、
// ServiceProvider、ServiceDiscovery三个接口，通过它我们可以很轻易的实现Service Discovery
private final ServiceDiscovery<ServiceInfo> serviceDiscovery;
private ILoadBalance<ServiceInstance<ServiceInfo>> loadBalance;
public ZookeeperRegistryService(String registryAddress) throws Exception {
CuratorFramework client= CuratorFrameworkFactory
.newClient(registryAddress,new ExponentialBackoffRetry(1000,3));
JsonInstanceSerializer<ServiceInfo> serializer=new JsonInstanceSerializer<>(ServiceInfo.class);
this.serviceDiscovery= ServiceDiscoveryBuilder.builder(ServiceInfo.class)
.client(client)
.serializer(serializer)
.basePath(REGISTRY_PATH)
.build();
this.serviceDiscovery.start();
loadBalance=new RandomLoadBalance();
}
@Override
public void register(ServiceInfo serviceInfo) throws Exception {
log.info("开始注册服务，{}",serviceInfo);
ServiceInstance<ServiceInfo> serviceInstance=ServiceInstance
.<ServiceInfo>builder().name(serviceInfo.getServiceName())
.address(serviceInfo.getServiceAddress())
.port(serviceInfo.getServicePort())
.payload(serviceInfo)
.build();
serviceDiscovery.registerService(serviceInstance);
}
@Override
public void unRegister(ServiceInfo serviceInfo) throws Exception {
ServiceInstance<ServiceInfo> serviceInstance=ServiceInstance.<ServiceInfo>builder()
.name(serviceInfo.getServiceName())
.address(serviceInfo.getServiceAddress())
.port(serviceInfo.getServicePort())
.payload(serviceInfo)
.build();
serviceDiscovery.unregisterService(serviceInstance);
}
@Override
public ServiceInfo discovery(String serviceName) throws Exception {
Collection<ServiceInstance<ServiceInfo>> serviceInstances= serviceDiscovery
.queryForInstances(serviceName);
//通过负载均衡返回某个具体实例
ServiceInstance<ServiceInfo> serviceInstance=loadBalance.select((List<ServiceInstance<ServiceInfo>>)serviceInstances);
if(serviceInstance!=null){
return serviceInstance.getPayload();
}
return null;
}
}由于服务端发现服务时可能有多个，所以需要用到负载均衡算法来实现
ILoadBalance
public interface ILoadBalance<T> {
T select(List<T> servers);
}AbstractLoadBalance
public abstract class AbstractLoadBanalce implements ILoadBalance<ServiceInstance<ServiceInfo>> {
@Override
public ServiceInstance<ServiceInfo> select(List<ServiceInstance<ServiceInfo>> servers){
if(servers==null||servers.size()==0){
return null;
}
if(servers.size()==1){
return servers.get(0);
}
return doSelect(servers);
}
protected abstract ServiceInstance<ServiceInfo> doSelect(List<ServiceInstance<ServiceInfo>> servers);
}RandomLoadBalance
public class RandomLoadBalance extends AbstractLoadBanalce {
@Override
protected ServiceInstance<ServiceInfo> doSelect(List<ServiceInstance<ServiceInfo>> servers) {
int length=servers.size();
Random random=new Random();
return servers.get(random.nextInt(length));
}
}
public enum RegistryType {
ZOOKEEPER((byte)0),
EUREKA((byte)1);
private byte code;
RegistryType(byte code) {
this.code=code;
}
public byte code(){
return this.code;
}
public static RegistryType findByCode(byte code) {
for (RegistryType rt : RegistryType.values()) {
if (rt.code() == code) {
return rt;
}
}
return null;
}
}
public class RegistryFactory {
public static IRegistryService createRegistryService(String address,RegistryType registryType){
IRegistryService registryService=null;
try {
switch (registryType) {
case ZOOKEEPER:
registryService = new ZookeeperRegistryService(address);
break;
case EUREKA:
//TODO
break;
default:
registryService = new ZookeeperRegistryService(address);
break;
}
}catch (Exception e){
e.printStackTrace();
}
return registryService;
}
}修改服务端增加服务注册
修改netty-rpc-protocol模块，加入注册中心的支持
按照下面case标注部分，表示要修改的内容
@Slf4j
public class SpringRpcProviderBean implements InitializingBean, BeanPostProcessor {
private final int serverPort;
private final String serverAddress;
private final IRegistryService registryService; //修改部分,增加注册中心实现
public SpringRpcProviderBean(int serverPort,IRegistryService registryService) throws UnknownHostException {
this.serverPort = serverPort;
InetAddress address=InetAddress.getLocalHost();
this.serverAddress=address.getHostAddress();
this.registryService=registryService; //修改部分,增加注册中心实现
}
@Override
public void afterPropertiesSet() throws Exception {
log.info("begin deploy Netty Server to host {},on port {}",this.serverAddress,this.serverPort);
new Thread(()->{
try {
new NettyServer(this.serverAddress,this.serverPort).startNettyServer();
} catch (Exception e) {
log.error("start Netty Server Occur Exception,",e);
e.printStackTrace();
}
}).start();
}
@Override
public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
if(bean.getClass().isAnnotationPresent(GpRemoteService.class)){ //针对存在该注解的服务进行发布
Method[] methods=bean.getClass().getDeclaredMethods();
for(Method method: methods){
String serviceName=bean.getClass().getInterfaces()[0].getName();
String key=serviceName+"."+method.getName();
BeanMethod beanMethod=new BeanMethod();
beanMethod.setBean(bean);
beanMethod.setMethod(method);
Mediator.beanMethodMap.put(key,beanMethod);
try {
//修改部分,增加注册中心实现
ServiceInfo serviceInfo = new ServiceInfo();
serviceInfo.setServiceAddress(this.serverAddress);
serviceInfo.setServicePort(this.serverPort);
serviceInfo.setServiceName(serviceName);
registryService.register(serviceInfo);//修改部分,增加注册中心实现
}catch (Exception e){
log.error("register service {} faild",serviceName,e);
}
}
}
return bean;
}
}修改RpcServerProperties，增加注册中心的配置
@Data
@ConfigurationProperties(prefix = "gp.rpc")
public class RpcServerProperties {
private int servicePort;
private byte registerType;
private String registryAddress;
}增加注册中心的注入。
@Configuration
@EnableConfigurationProperties(RpcServerProperties.class)
public class RpcProviderAutoConfiguration {
@Bean
public SpringRpcProviderBean rpcProviderBean(RpcServerProperties rpcServerProperties) throws UnknownHostException {
//添加注册中心
IRegistryService registryService=RegistryFactory.createRegistryService(rpcServerProperties.getRegistryAddress(), RegistryType.findByCode(rpcServerProperties.getRegisterType()));
return new SpringRpcProviderBean(rpcServerProperties.getServicePort(),registryService);
}
}修改netty-rpc-provider中的application.properties。
gp.rpc.servicePort=20880
gp.rpc.registerType=0
gp.rpc.registryAddress=192.168.221.128:2181修改客户端，增加服务发现
客户端需要修改的地方较多，下面这些修改的代码，都是netty-rpc-protocol模块中的类。
增加注册中心类型和注册中心地址的选项
@Data
public class RpcClientProperties {
private String serviceAddress="192.168.1.102";
private int servicePort=20880;
private byte registryType;
private String registryAddress;
}原本是静态地址，现在修改成了从注册中心获取地址
@Slf4j
public class NettyClient {
private final Bootstrap bootstrap;
private final EventLoopGroup eventLoopGroup=new NioEventLoopGroup();
/* private String serviceAddress;
private int servicePort;*/
public NettyClient(){
log.info("begin init NettyClient");
bootstrap=new Bootstrap();
bootstrap.group(eventLoopGroup)
.channel(NioSocketChannel.class)
.handler(new RpcClientInitializer());
/* this.serviceAddress=serviceAddress;
this.servicePort=servicePort;*/
}
public void sendRequest(RpcProtocol<RpcRequest> protocol, IRegistryService registryService) throws Exception {
ServiceInfo serviceInfo=registryService.discovery(protocol.getContent().getClassName());
ChannelFuture future=bootstrap.connect(serviceInfo.getServiceAddress(),serviceInfo.getServicePort()).sync();
future.addListener(listener->{
if(future.isSuccess()){
log.info("connect rpc server {} success.",serviceInfo.getServiceAddress());
}else{
log.error("connect rpc server {} failed .",serviceInfo.getServiceAddress());
future.cause().printStackTrace();
eventLoopGroup.shutdownGracefully();
}
});
log.info("begin transfer data");
future.channel().writeAndFlush(protocol);
}
}将静态ip和地址，修改成IRegistryService
@Slf4j
public class RpcInvokerProxy implements InvocationHandler {
/* private String serviceAddress;
private int servicePort;*/
IRegistryService registryService;
public RpcInvokerProxy(IRegistryService registryService) {
/* this.serviceAddress = serviceAddress;
this.servicePort = servicePort;*/
this.registryService=registryService;
}
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
log.info("begin invoke target server");
//组装参数
RpcProtocol<RpcRequest> protocol=new RpcProtocol<>();
long requestId= RequestHolder.REQUEST_ID.incrementAndGet();
Header header=new Header(RpcConstant.MAGIC, SerialType.JSON_SERIAL.code(), ReqType.REQUEST.code(),requestId,0);
protocol.setHeader(header);
RpcRequest request=new RpcRequest();
request.setClassName(method.getDeclaringClass().getName());
request.setMethodName(method.getName());
request.setParameterTypes(method.getParameterTypes());
request.setParams(args);
protocol.setContent(request);
//发送请求
NettyClient nettyClient=new NettyClient();
//构建异步数据处理
RpcFuture<RpcResponse> future=new RpcFuture<>(new DefaultPromise<>(new DefaultEventLoop()));
RequestHolder.REQUEST_MAP.put(requestId,future);
nettyClient.sendRequest(protocol,this.registryService);
return future.getPromise().get().getData();
}
}修改引用bean，增加注册中心配置
public class SpringRpcReferenceBean implements FactoryBean<Object> {
private Class<?> interfaceClass;
private Object object;
/* private String serviceAddress;
private int servicePort;*/
//修改增加注册中心
private byte registryType;
private String registryAddress;
@Override
public Object getObject() throws Exception {
return object;
}
public void init(){
//修改增加注册中心
IRegistryService registryService= RegistryFactory.createRegistryService(this.registryAddress, RegistryType.findByCode(this.registryType));
this.object= Proxy.newProxyInstance(this.interfaceClass.getClassLoader(),
new Class<?>[]{this.interfaceClass},
new RpcInvokerProxy(registryService));
}
@Override
public Class<?> getObjectType() {
return this.interfaceClass;
}
public void setInterfaceClass(Class<?> interfaceClass) {
this.interfaceClass = interfaceClass;
}
/* public void setServiceAddress(String serviceAddress) {
this.serviceAddress = serviceAddress;
}
public void setServicePort(int servicePort) {
this.servicePort = servicePort;
}*/
public void setRegistryType(byte registryType) {
this.registryType = registryType;
}
public void setRegistryAddress(String registryAddress) {
this.registryAddress = registryAddress;
}
}
@Slf4j
public class SpringRpcReferencePostProcessor implements ApplicationContextAware, BeanClassLoaderAware, BeanFactoryPostProcessor {
private ApplicationContext context;
private ClassLoader classLoader;
private RpcClientProperties clientProperties;
public SpringRpcReferencePostProcessor(RpcClientProperties clientProperties) {
this.clientProperties = clientProperties;
}
//保存发布的引用bean信息
private final Map<String, BeanDefinition> rpcRefBeanDefinitions=new ConcurrentHashMap<>();
@Override
public void setBeanClassLoader(ClassLoader classLoader) {
this.classLoader=classLoader;
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.context=applicationContext;
}
@Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
for (String beanDefinitionname:beanFactory.getBeanDefinitionNames()){
//遍历bean定义，然后获取到加载的bean，遍历这些bean中的字段，是否携带GpRemoteReference注解
//如果有，则需要构建一个动态代理实现
BeanDefinition beanDefinition=beanFactory.getBeanDefinition(beanDefinitionname);
String beanClassName=beanDefinition.getBeanClassName();
if(beanClassName!=null){
Class<?> clazz=ClassUtils.resolveClassName(beanClassName,this.classLoader);
ReflectionUtils.doWithFields(clazz,this::parseRpcReference);
}
}
//将@GpRemoteReference注解的bean，构建一个动态代理对象
BeanDefinitionRegistry registry=(BeanDefinitionRegistry)beanFactory;
this.rpcRefBeanDefinitions.forEach((beanName,beanDefinition)->{
if(context.containsBean(beanName)){
log.warn("SpringContext already register bean {}",beanName);
return;
}
registry.registerBeanDefinition(beanName,beanDefinition);
log.info("registered RpcReferenceBean {} success.",beanName);
});
}
private void parseRpcReference(Field field){
GpRemoteReference gpRemoteReference=AnnotationUtils.getAnnotation(field,GpRemoteReference.class);
if(gpRemoteReference!=null) {
BeanDefinitionBuilder builder=BeanDefinitionBuilder.genericBeanDefinition(SpringRpcReferenceBean.class);
builder.setInitMethodName(RpcConstant.INIT_METHOD_NAME);
builder.addPropertyValue("interfaceClass",field.getType());
/*builder.addPropertyValue("serviceAddress",clientProperties.getServiceAddress());
builder.addPropertyValue("servicePort",clientProperties.getServicePort());*/
builder.addPropertyValue("registryType",clientProperties.getRegistryType());
builder.addPropertyValue("registryAddress",clientProperties.getRegistryAddress());
BeanDefinition beanDefinition=builder.getBeanDefinition();
rpcRefBeanDefinitions.put(field.getName(),beanDefinition);
}
}
}
@Configuration
public class RpcRefernceAutoConfiguration implements EnvironmentAware{
@Bean
public SpringRpcReferencePostProcessor postProcessor(){
String address=environment.getProperty("gp.serviceAddress");
int port=Integer.parseInt(environment.getProperty("gp.servicePort"));
RpcClientProperties rc=new RpcClientProperties();
rc.setServiceAddress(address);
rc.setServicePort(port);
rc.setRegistryType(Byte.parseByte(environment.getProperty("gp.registryType")));
rc.setRegistryAddress(environment.getProperty("gp.registryAddress"));
return new SpringRpcReferencePostProcessor(rc);
}
private Environment environment;
@Override
public void setEnvironment(Environment environment) {
this.environment=environment;
}
}修改netty-rpc-consumer模块中的配置
gp.serviceAddress=192.168.1.102
gp.servicePort=20880
gp.registryType=0
gp.registryAddress=192.168.221.128:2181负载均衡的测试
增加一个服务端的启动类，并且修改端口。然后客户端不需要重启的情况下刷新浏览器，即可看到负载均衡的效果。
图7-5
需要源码的同学，请关注公众号[跟着Mic学架构]，回复关键字[rpc]，即可获得
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