alibaba jarslink

alibaba jarslink frame course

demo Of github Address ：https://github.com/superRabbitMan/jarslink-demo

What is? jarslink

JarsLink ( Original name Titan) It's based on JAVA Modular development framework for , It provides dynamic loading of modules at run time （ One JAR package ）、 Uninstall modules and calls between modules API.

Why use jarslink

Isolation,

• Class isolation ： The framework is for each module Class Use a separate ClassLoader To load the , Each module can rely on different versions of the same framework .
• Instance isolation ： The framework creates a separate for each module Spring Context , To load... In the module BEAN, Instantiation failure will not affect other modules .
• Resource isolation ： Resource isolation between modules will be supported later , Each module uses a separate CPU And memory resources .

dynamic

• Dynamic release ： Modules can be dynamically loaded into the system at run time , Realize the new functions without restarting and publishing the system . Support breaking through the parental delegation mechanism , Load the class already loaded by the parent loader at runtime , The implementation of the module upgrade dependency package does not require system release .
• Dynamic unloading ： Modules can be dynamically unloaded at runtime , No function is required to realize fast offline .

Ease of use

• Provides a versatile and flexible API Let the system interact with the module .

download

\1. Official website :https://github.com/alibaba/jarslink

\2. Other ways ：https://oss.sonatype.org/#nexus-search;quick~jarslink

Introduce projects

As for how to create a Maven The project is not introduced here , Just Baidu yourself

# The main POM, Here please use 1.6 Version above , Because the following introduction has a function 1.6 It is only supported in versions above 



<dependency>



  <groupId>com.alipay.jarslink</groupId>



  <artifactId>jarslink-api</artifactId>



  <version>1.6.1.20180301</version>



</dependency>



# rely on POM



<dependencies>



        <dependency>



            <groupId>org.springframework</groupId>



            <artifactId>spring-aop</artifactId>



            <version>5.0.5.RELEASE</version>



        </dependency>



        <dependency>



            <groupId>org.springframework</groupId>



            <artifactId>spring-web</artifactId>



            <version>5.0.5.RELEASE</version>



            <optional>true</optional>



        </dependency>



        <dependency>



            <groupId>commons-logging</groupId>



            <artifactId>commons-logging</artifactId>



            <version>1.1.3</version>



        </dependency>



        <dependency>



            <groupId>org.apache.commons</groupId>



            <artifactId>commons-lang3</artifactId>



            <version>3.3.2</version>



        </dependency>



        <dependency>



            <groupId>commons-lang</groupId>



            <artifactId>commons-lang</artifactId>



            <version>2.6</version>



        </dependency>



        <dependency>



            <groupId>org.slf4j</groupId>



            <artifactId>slf4j-api</artifactId>



            <version>1.7.7</version>



        </dependency>



        <dependency>



            <groupId>commons-collections</groupId>



            <artifactId>commons-collections</artifactId>



            <version>3.2.1</version>



        </dependency>



        <dependency>



            <groupId>com.google.guava</groupId>



            <artifactId>guava</artifactId>



            <version>17.0</version>



        </dependency>



        <dependency>



            <groupId>junit</groupId>



            <artifactId>junit</artifactId>



            <version>4.12</version>



        </dependency>



    </dependencies>

Introduce modules jar package

modular jar File import is unnecessary buildpath Import project's , You can put it in CDEF Any position of the disc is OK , Because this module jar Files are not launched with the project , We use jarslink Framework to reference it .

​ For ease of invocation , I put it in the project resources Under the document ：

The most important object

<!--  Module loading engine , Responsible for loading modules --><bean name="moduleLoader" class="com.alipay.jarslink.api.impl.ModuleLoaderImpl"></bean>
<!--  Module manager , Responsible for registration , uninstall , Find modules and execute Action --><bean name="moduleManager" class="com.alipay.jarslink.api.impl.ModuleManagerImpl"></bean>

To configure jarslink.xml file

<?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">



 



       <!-- Module loading engine -->



       <bean id="moduleLoader" name="moduleLoader" class="com.alipay.jarslink.api.impl.ModuleLoaderImpl" />



 



       <!-- Module manager -->



       <bean id="moduleManager" name="moduleManager" class="com.alipay.jarslink.api.impl.ModuleManagerImpl" />



 



</beans>

Configure module information

public static ModuleConfig buildModuleConfig() {
    



    URL demoModule = Thread.currentThread().getContextClassLoader().getResource("jarslink-module-demo-1.0.0.jar");// Load module jar package , Can be in any path 



    ModuleConfig moduleConfig = new ModuleConfig();



    moduleConfig.setName("hello-world");// Set the module name 



    moduleConfig.setEnabled(true);



    moduleConfig.setVersion("1.0.0");// Set version 



    moduleConfig.setProperties(ImmutableMap.of("svnPath", new Object()));



    moduleConfig.setModuleUrl(ImmutableList.of(demoModule));



    return moduleConfig;



}

The first call demo

package com.alibaba.test;



 



import com.alipay.jarslink.api.Action;



import com.alipay.jarslink.api.Module;



import com.alipay.jarslink.api.ModuleLoader;



import com.alipay.jarslink.api.ModuleManager;



import com.alipay.jarslink.api.impl.AbstractModuleRefreshScheduler;



import com.alipay.jarslink.api.impl.ModuleManagerImpl;



import org.junit.Test;



import org.junit.runner.RunWith;



import org.springframework.beans.factory.annotation.Autowired;



import org.springframework.test.context.ContextConfiguration;



import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;



 



import java.util.Map;



import java.util.Set;



 



/** * Created by HASEE on 2018/4/22. */



@RunWith(SpringJUnit4ClassRunner.class)



@ContextConfiguration(locations = {
    "classpath*:jarslink.xml"})



public class JarsLinkTest {
    



 



    @Autowired



    private ModuleLoader moduleLoader;



    @Autowired



    private ModuleManager moduleManager; 



 



    @Test



    public void test1() {
    



// System.out.println("moduleLoader = " + moduleLoader);



// System.out.println("moduleManager = " + moduleManager);



        Module module = moduleLoader.load(ModuleRefreshSchedulerImpl.buildModuleConfig());// Load module , Load a module 



        moduleManager.register(module);// Register module information 



        /* Get the specified Action, Execution mode I */



        Module mod = moduleManager.find("hello-world");



        Map<String, Action> actions = mod.getActions();



// Set<String> keys = actions.keySet();



// for (String key : keys) {
    



// System.out.println(key + ", " + actions.get(key));



// }



        Action xmlaction = actions.get("XMLACTION");



        System.out.println(xmlaction.execute("hello world"));



        /* Get the specified Action, Mode II */



        //doAction Parameters ： Module action The name of ,action in execute Method parameters 



        String result = module.doAction("XMLACTION", "hello world");



        System.out.println(result);



    }



 



}

summary

Jarslink The use of is so simple ,1） Load module jar.2） Registration module .3） Call the Action

Development module （ Create a new one maven project ）

​ Module and Action The relationship between , One jar A package is a module , There is one or more... In the module Action class , What we call is the module Action Acquisition function . All development modules are actually development Action.

​ Action The development of is also relatively simple , As long as the implementation com.alipay.jarslink.api.Action<R,T> The class can ,Action Yes 2 Generic classes ,R Represents the incoming parameter ,T Indicates the return parameter .

​ Action There are two methods to implement ,1）T execute(Rvar1);.2）String getActionName();.execute The method is Action Function method provided .getActionName Method is to get the name of the , The name must be unique , If it is not unique, then it will not know which module to execute Action.

package com.alibaba.action;



 



import com.alipay.jarslink.api.Action;



 



/** * Created by HASEE on 2018/4/22. */



public class HelloWorldAction implements Action<String, String> {
    



 



    @Override



    public String execute(String s) {
    



        return s + ":hello world";



    }



 



    @Override



    public String getActionName() {
    



        return "hello-world-action";



    }



 



}

To configure xml file

​ Please note the directory where the configuration files are stored ,resources/META-INF/spring/*.xml, When loading the module, you will read the configuration information in this directory .

The configuration information is as follows

<?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:p="http://www.springframework.org/schema/p"



       xmlns:context="http://www.springframework.org/schema/context"



       xmlns:webflow="http://www.springframework.org/schema/webflow-config"



       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd



         http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd



         http://www.springframework.org/schema/webflow-config http://www.springframework.org/schema/webflow-config/spring-webflow-config-2.0.xsd" default-autowire="byName">


    <context:annotation-config/>


    <!-- establish Action-->
    <bean id="helloWorldAction" class="com.alibaba.action.HelloWorldAction"/>

    <bean id="welComeAction" class="com.alibaba.action.WelComeAction" />

</beans>

Compile the file and go everywhere Jar package , Such a module is developed , This module contains a HelloworldAction Class .

​ Will export jar The package is introduced into the first case resources Under the folder , You can call .

The second call demo

Configure self-developed modules

public static ModuleConfig buildModuleConfig_Demo() {
    

    URL demoModule = Thread.currentThread().getContextClassLoader().getResource("jarslink-demo-action-1.0-SNAPSHOT.jar");

    ModuleConfig moduleConfig = new ModuleConfig();
    moduleConfig.setName("demo-action");
    moduleConfig.setEnabled(true);
    moduleConfig.setVersion("1.0.0");
    // Configure custom properties Information 
    moduleConfig.setProperties(ImmutableMap.of("svnPath", new Object()));

    moduleConfig.setModuleUrl(ImmutableList.of(demoModule));



    return moduleConfig;



}
package com.alibaba.test;



import com.alipay.jarslink.api.Action;

import com.alipay.jarslink.api.Module;

import com.alipay.jarslink.api.ModuleLoader;

import com.alipay.jarslink.api.ModuleManager;

import com.alipay.jarslink.api.impl.AbstractModuleRefreshScheduler;

import com.alipay.jarslink.api.impl.ModuleManagerImpl;

import org.junit.Test;
import org.junit.runner.RunWith;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import java.util.Map;
import java.util.Set;



@RunWith(SpringJUnit4ClassRunner.class)


@ContextConfiguration(locations = {
    "classpath*:jarslink.xml"})
public class JarsLinkTest {
    

    @Autowired
    private ModuleLoader moduleLoader;


    @Autowired

    private ModuleManager moduleManager; 


    @Test
    public void test2() {
    

        // Load and register modules 

        Module module = moduleLoader.load(ModuleRefreshSchedulerImpl.buildModuleConfig_Demo());// Load module , Load a module 

        moduleManager.register(module);

        String result = module.doAction("hello-world-action", "rabbit");

        System.out.println("result = " + result); 

    }

}

summary

​ A modular Action Development is that simple ,1） Create your own Action.2） Configuration in profile bean Information . The problem is developing one at a time Action You need to add a configuration file to the configuration file <beanid=”” name=”” class=”” />, Once there are more classes , Such management is more troublesome , Fortunately 1.6 The function of scanning package is provided in version .

Scan package function

Action The development process is the same , But in xml No configuration information is required in the file , Instead, you can scan the specified package when calling , Here's the key code .

package com.alibaba.test;



 



import com.alipay.jarslink.api.Module;



import com.alipay.jarslink.api.ModuleConfig;



import com.alipay.jarslink.api.ModuleLoader;



import com.alipay.jarslink.api.ModuleManager;



import com.google.common.collect.ImmutableList;



import com.google.common.collect.ImmutableMap;



import org.junit.Test;



import org.junit.runner.RunWith;



import org.springframework.beans.factory.annotation.Autowired;



import org.springframework.test.context.ContextConfiguration;



import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;



import java.net.URL;

/** * Created by HASEE on 2018/4/23. */



@RunWith(SpringJUnit4ClassRunner.class)



@ContextConfiguration(locations = {
    "classpath*:jarslink.xml"})



public class AnnoJarsLinkTest {
    





    @Autowired
    private ModuleLoader moduleLoader;



    @Autowired
    private ModuleManager moduleManager;



    @Test
    public void test1() {
    

        URL demoModule = Thread.currentThread().getContextClassLoader().getResource("jarslink-demo-anno-action-1.0-SNAPSHOT.jar");

        ModuleConfig moduleConfig = new ModuleConfig();

        moduleConfig.setName("anno-action");

        moduleConfig.setEnabled(true);

        moduleConfig.setVersion("1.0.0");

        moduleConfig.setProperties(ImmutableMap.of("svnPath", new Object()));

        moduleConfig.setModuleUrl(ImmutableList.of(demoModule));

        // Scan the... Under the module Action

        moduleConfig.addScanPackage("com.alibaba.action");

        Module module = moduleLoader.load(moduleConfig);

        moduleManager.register(module);

        System.out.println("string to long " + module.doAction("string-to-long", "500"));


    }


}

Best practices

HTTP Request forwarding

Determine the requested module and... Through the request path action

private ModuleManager moduleManager;


@RequestMapping(value = "module/{moduleName}/{actionName}/process.json", method = {
     RequestMethod.GET,RequestMethod.POST })

public Object process(HttpServletRequest request, HttpServletResponse response) {
    


	Map<String, String> pathVariables = resolvePathVariables(request);



	String moduleName = pathVariables.get("moduleName").toUpperCase()



	String actionName = pathVariables.get("actionName").toUpperCase()



	String actionRequest = XXX;



	return moduleManager.doAction(moduleName,



            actionName, actionRequest);



}


private Map<String, String> resolvePathVariables(HttpServletRequest request) {
    


        return (Map<String, String>) request
.getAttribute(HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE);

    }

How to publish modules

There are two options ：

programme 1 Pull mode

• 1： Compile the code locally and package it into JAR package .
• 2： hold JAR Upload to a remote file server , For example, Alibaba cloud's OSS.
• 3： The application is downloaded from a remote server JAR, The configuration information can be stored in JAR in , Such as version number ,JAR name .

programme 2 Push mode

• 1： Compile the code locally and package it into JAR package .
• 2： hold JAR direct SCP To a directory on the server .
• 3： The application checks the directory specified by the service JAR Is there an update , If there is an update, load it .