netty 案例,netty4.1 高级应用篇一,手写 RPC 框架第一章《自定义配置 xml》
案例介绍
本案例通过三个章节来实现一共简单的rpc框架,用于深入学习rpc框架是如何通信的,当前章节主要介绍如何自定义xml文件并进行解析。想解析自定义的xml首先定义自己的xsd文件,并且实现spring的NamespaceHandlerSupport、BeanDefinitionParser,两个方法进行处理。
>远程过程调用协议
RPC(Remote Procedure Call)—远程过程调用,它是一种通过网络从远程计算机程序上请求服务,而不需要了解底层网络技术的协议。RPC协议假定某些传输协议的存在,如TCP或UDP,为通信程序之间携带信息数据。在OSI网络通信模型中,RPC跨越了传输层和应用层。RPC使得开发包括网络分布式多程序在内的应用程序更加容易。
RPC采用客户机/服务器模式。请求程序就是一个客户机,而服务提供程序就是一个服务器。首先,客户机调用进程发送一个有进程参数的调用信息到服务进程,然后等待应答信息。在服务器端,进程保持睡眠状态直到调用信息到达为止。当一个调用信息到达,服务器获得进程参数,计算结果,发送答复信息,然后等待下一个调用信息,最后,客户端调用进程接收答复信息,获得进程结果,然后调用执行继续进行。
>Dubbo是 [1] 阿里巴巴公司开源的一个高性能优秀的服务框架,使得应用可通过高性能的 RPC 实现服务的输出和输入功能,可以和 [2] Spring框架无缝集成。
Dubbo是一款高性能、轻量级的开源Java RPC框架,它提供了三大核心能力:面向接口的远程方法调用,智能容错和负载均衡,以及服务自动注册和发现。
环境准备
1、jdk 1.8.0
2、IntelliJ IDEA Community Edition 2018.3.1 x64
代码示例
itstack-demo-rpc-01└── src └── main │ ├── java │ │ └── org.itstack.demo.rpc.config │ │ ├── spring │ │ │ ├── bean │ │ │ │ ├── ConsumerBean.java │ │ │ │ ├── ProviderBean.java │ │ │ │ └── ServerBean.java │ │ │ ├── MyBeanDefinitionParser.java │ │ │ └── MyNamespaceHandler.java │ │ ├── ConsumerConfig.java │ │ ├── ProviderConfig.java │ │ └── ProviderConfig.java │ └── resource │ └── META-INF │ ├── rpc.xsd │ ├── spring.handlers │ └── spring.schemas └── test ├── java │ └── org.itstack.demo.test │ ├── service │ │ ├── impl │ │ │ └── HelloServiceImpl.java │ │ └── HelloService.java │ └── ApiTest.java └── resource ├── itstack-rpc-consumer.xml ├── itstack-rpc-provider.xml └── log4j.xml
>ProviderConfig.java
public class ProviderConfig { private String nozzle; //接口 private String ref; //映射 private String alias; //别名 //发布 protected void doExport() { System.out.format("生产者信息=> [接口:%s] [映射:%s] [别名:%s] \r\n", nozzle, ref, alias); } public String getNozzle() { return nozzle; } public void setNozzle(String nozzle) { this.nozzle = nozzle; } public String getRef() { return ref; } public void setRef(String ref) { this.ref = ref; } public String getAlias() { return alias; } public void setAlias(String alias) { this.alias = alias; }}
>ProviderBean.java
public class ProviderBean extends ProviderConfig implements ApplicationContextAware { @Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { //发布生产者 doExport(); }}
>MyBeanDefinitionParser.java
public class MyBeanDefinitionParser implements BeanDefinitionParser { private final Class<?> beanClass; MyBeanDefinitionParser(Class<?> beanClass) { this.beanClass = beanClass; } @Override public BeanDefinition parse(Element element, ParserContext parserContext) { RootBeanDefinition beanDefinition = new RootBeanDefinition(); beanDefinition.setBeanClass(beanClass); beanDefinition.setLazyInit(false); String beanName = element.getAttribute("id"); parserContext.getRegistry().registerBeanDefinition(beanName, beanDefinition); for (Method method : beanClass.getMethods()) { if (!isProperty(method, beanClass)) continue; String name = method.getName(); String methodName = name.substring(3, 4).toLowerCase() + name.substring(4); String value = element.getAttribute(methodName); beanDefinition.getPropertyValues().addPropertyValue(methodName, value); } return beanDefinition; } private boolean isProperty(Method method, Class beanClass) { String methodName = method.getName(); boolean flag = methodName.length() > 3 && methodName.startsWith("set") && Modifier.isPublic(method.getModifiers()) && method.getParameterTypes().length == 1; Method getter = null; if (!flag) return false; Class<?> type = method.getParameterTypes()[0]; try { getter = beanClass.getMethod("get" + methodName.substring(3)); } catch (NoSuchMethodException ignore) { } if (null == getter) { try { getter = beanClass.getMethod("is" + methodName.substring(3)); } catch (NoSuchMethodException ignore) { } } flag = getter != null && Modifier.isPublic(getter.getModifiers()) && type.equals(getter.getReturnType()); return flag; }}
>MyNamespaceHandler.java
public class MyNamespaceHandler extends NamespaceHandlerSupport { @Override public void init() { registerBeanDefinitionParser("consumer", new MyBeanDefinitionParser(ConsumerBean.class)); registerBeanDefinitionParser("provider", new MyBeanDefinitionParser(ProviderBean.class)); registerBeanDefinitionParser("server", new MyBeanDefinitionParser(ServerBean.class)); }}
>rpc.xsd
<?xml version="1.0" encoding="UTF-8"?><xsd:schema xmlns="http://rpc.itstack.org/schema/rpc" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:beans="http://www.springframework.org/schema/beans" targetNamespace="http://rpc.itstack.org/schema/rpc" elementFormDefault="qualified" attributeFormDefault="unqualified"> <xsd:import namespace="http://www.springframework.org/schema/beans"/> <!-- org.itstack.demo.rpc.config.ServerConfig --> <xsd:element name="server"> <xsd:complexType> <xsd:complexContent> <xsd:extension base="beans:identifiedType"> <xsd:attribute name="host" type="xsd:string"> <xsd:annotation> <xsd:documentation><![CDATA[ 栈台地点 ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> <xsd:attribute name="port" type="xsd:string"> <xsd:annotation> <xsd:documentation><![CDATA[ 栈台岸口 ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> </xsd:extension> </xsd:complexContent> </xsd:complexType> </xsd:element> <!-- org.itstack.demo.rpc.config.ConsumerConfig --> <xsd:element name="consumer"> <xsd:complexType> <xsd:complexContent> <xsd:extension base="beans:identifiedType"> <xsd:attribute name="nozzle" type="xsd:string"> <xsd:annotation> <xsd:documentation><![CDATA[ 接口名称 ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> <xsd:attribute name="alias" type="xsd:string"> <xsd:annotation> <xsd:documentation><![CDATA[ 服务别名分组信息 ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> </xsd:extension> </xsd:complexContent> </xsd:complexType> </xsd:element> <!-- org.itstack.demo.rpc.config.ProviderConfig --> <xsd:element name="provider"> <xsd:complexType> <xsd:complexContent> <xsd:extension base="beans:identifiedType"> <xsd:attribute name="nozzle" type="xsd:string"> <xsd:annotation> <xsd:documentation><![CDATA[ 接口名称 ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> <xsd:attribute name="ref" type="xsd:string"> <xsd:annotation> <xsd:documentation><![CDATA[ 接口实现类 ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> <xsd:attribute name="alias" type="xsd:string"> <xsd:annotation> <xsd:documentation><![CDATA[ 服务别名分组信息 ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> </xsd:extension> </xsd:complexContent> </xsd:complexType> </xsd:element></xsd:schema>
>spring.handlers
http\://rpc.itstack.org/schema/rpc=org.itstack.demo.rpc.config.spring.MyNamespaceHandler
>spring.schemas
http\://rpc.itstack.org/schema/rpc/rpc.xsd=META-INF/rpc.xsd
测试部分
>itstack-rpc-consumer.xml
<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:rpc="http://rpc.itstack.org/schema/rpc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://rpc.itstack.org/schema/rpc http://rpc.itstack.org/schema/rpc/rpc.xsd"> <!-- redis配置,保存链接 --> <rpc:server id="consumer_itstack" host="127.0.0.1" port="6379"/> <rpc:consumer id="consumer_helloService" nozzle="org.itstack.demo.test.service.HelloService" alias="itStackRpc"/></beans>
>itstack-rpc-provider.xml
<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:rpc="http://rpc.itstack.org/schema/rpc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://rpc.itstack.org/schema/rpc http://rpc.itstack.org/schema/rpc/rpc.xsd"> <rpc:provider id="provider_helloService" nozzle="org.itstack.demo.test.service.HelloService" ref="helloService" alias="itStackRpc" /></beans>
>ApiTest.java
package org.itstack.demo.test;import org.springframework.context.support.ClassPathXmlApplicationContext;/** * http://www.itstack.org * create by fuzhengwei on 2019/5/4 * 本章节主要介绍如何读取自定义配置xml文件字段信息 */public class ApiTest { public static void main(String[] args) { String[] configs = {"itstack-rpc-consumer.xml", "itstack-rpc-provider.xml"}; new ClassPathXmlApplicationContext(configs); }}
测试结果
2019-05-07 19:44:24,805 main INFO [org.springframework.context.support.ClassPathXmlApplicationContext:prepareRefresh:510] - Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@299a06ac: startup date [Tue May 07 19:44:24 CST 2019]; root of context hierarchy2019-05-07 19:44:24,872 main INFO [org.springframework.beans.factory.xml.XmlBeanDefinitionReader:loadBeanDefinitions:315] - Loading XML bean definitions from class path resource [itstack-rpc-consumer.xml]2019-05-07 19:44:24,972 main INFO [org.springframework.beans.factory.xml.XmlBeanDefinitionReader:loadBeanDefinitions:315] - Loading XML bean definitions from class path resource [itstack-rpc-provider.xml]2019-05-07 19:44:25,008 main INFO [org.springframework.beans.factory.support.DefaultListableBeanFactory:preInstantiateSingletons:577] - Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@192b07fd: defining beans [consumer_itstack,consumer_helloService,provider_helloService]; root of factory hierarchy服务端信息=> [注册中心地址:127.0.0.1] [注册中心端口:6379] 生产者信息=> [接口:org.itstack.demo.test.service.HelloService] [映射:helloService] [别名:itStackRpc]
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