欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页

手写类似dubbo的rpc框架第一章《自定义配置xml》

程序员文章站 2022-06-01 21:32:40
...

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 hierarchy
2019-05-07 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] 
相关标签: rpc