spring-plugin简单使用

spring-plugin 是spring 官方提供的一个插件化设计方案，比如使用支持基于spring 的项目

项目结构

此简单测试项目是一个maven 多模块的，包含了一个plugin 契约模块，连个插件实现，以及一个bootstrap 启动入口

• 代码结构

├── README.md

├── bootstrap

│   ├── HELP.md

│   ├── pom.xml

│   └── src

│       └── main

│           ├── java

│           │   └── com

│           │       └── dalongplugin

│           │           └── bootstrap

│           │               ├── BootstrapApplication.java

│           │               └── demos

│           │                   └── web

│           │                       └── Api.java

│           └── resources

│               ├── application.properties

│               └── static

│                   └── index.html

├── plugin_a

│   ├── pom.xml

│   └── src

│       ├── main

│       │   ├── java

│       │   │   └── com

│       │   │       └── dalongplugina

│       │   │           └── PluginA.java

│       │   └── resources

│       └── test

│           └── java

├── plugin_b

│   ├── pom.xml

│   └── src

│       ├── main

│       │   ├── java

│       │   │   └── com

│       │   │       └── dalongpluginb

│       │   │           └── PluginB.java

│       │   └── resources

│       └── test

│           └── java

├── plugin_interface

│   ├── pom.xml

│   └── src

│       ├── main

│       │   ├── java

│       │   │   └── com

│       │   │       └── dalongpluginb

│       │   │           └── PluginContract.java

│       │   └── resources

│       └── test

│           └── java

└── pom.xml

代码说明

• plugin_interface
  就是一个接口定义

 

package com.dalongpluginb;

 

import org.springframework.plugin.core.Plugin;

 

public interface PluginContract extends Plugin<String> {

    String message(String input);

}

引用的包

<dependencies>

        <dependency>

            <groupId>org.springframework.plugin</groupId>

            <artifactId>spring-plugin-core</artifactId>

        </dependency>

</dependencies>

• plugina 实现

package com.dalongplugina;

 

import com.dalongpluginb.PluginContract;

import org.springframework.stereotype.Component;

 

@Component

public class PluginA implements PluginContract {

    @Override

    public String message(String input) {

        return String.format("plugina: %s", input);

    }

    @Override

    public boolean supports(String s) {

        return s.equalsIgnoreCase("plugina");

    }

}

maven 依赖

<dependencies>

        <dependency>

            <groupId>com.dalong</groupId>

            <artifactId>plugin_interface</artifactId>

            <version>1.0-SNAPSHOT</version>

            <scope>provided</scope>

        </dependency>

</dependencies>

pluginb 类似

• bootstrap 入口
  一个spring boot 项目，同时会添加插入契约定义，默认是一个spring boot web 项目
  maven 依赖

 

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>com.dalong</groupId>

    <artifactId>bootstrap</artifactId>

    <version>0.0.1-SNAPSHOT</version>

    <name>bootstrap</name>

    <description>bootstrap</description>

    <properties>

        <java.version>11</java.version>

        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>

        <spring-boot.version>2.4.2</spring-boot.version>

    </properties>

    <dependencies>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-web</artifactId>

        </dependency>

 

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-test</artifactId>

            <scope>test</scope>

        </dependency>

       // spring-plugin 依赖添加

        <dependency>

            <groupId>org.springframework.plugin</groupId>

            <artifactId>spring-plugin-core</artifactId>

            <version>2.0.0.RELEASE</version>

        </dependency>

        <dependency>

            <groupId>org.springframework.plugin</groupId>

            <artifactId>spring-plugin-metadata</artifactId>

            <version>2.0.0.RELEASE</version>

        </dependency>

        <dependency>

            <groupId>com.dalong</groupId>

            <artifactId>plugin_a</artifactId>

            <version>1.0-SNAPSHOT</version>

        </dependency>

        <dependency>

            <groupId>com.dalong</groupId>

            <artifactId>plugin_b</artifactId>

            <version>1.0-SNAPSHOT</version>

            <optional>true</optional>

        </dependency>

        <dependency>

            <groupId>com.dalong</groupId>

            <artifactId>plugin_interface</artifactId>

            <version>1.0-SNAPSHOT</version>

        </dependency>

 

    </dependencies>

    <dependencyManagement>

        <dependencies>

            <dependency>

                <groupId>org.springframework.boot</groupId>

                <artifactId>spring-boot-dependencies</artifactId>

                <version>${spring-boot.version}</version>

                <type>pom</type>

                <scope>import</scope>

            </dependency>

        </dependencies>

    </dependencyManagement>

 

    <build>

        <plugins>

            <plugin>

                <groupId>org.apache.maven.plugins</groupId>

                <artifactId>maven-compiler-plugin</artifactId>

                <version>3.8.1</version>

                <configuration>

                    <source>11</source>

                    <target>11</target>

                    <encoding>UTF-8</encoding>

                </configuration>

            </plugin>

            <plugin>

                <groupId>org.apache.maven.plugins</groupId>

                <artifactId>maven-jar-plugin</artifactId>

                <version>3.3.0</version>

                <configuration>

                    <archive>

                        // 移除jar maven 构建信息 

                        <addMavenDescriptor>false</addMavenDescriptor>

                    </archive>

                </configuration>

            </plugin>

          // 为了方便插件的加载没有使用spring boot 的fat jar 插件

            <plugin>

                <groupId>org.apache.maven.plugins</groupId>

                <artifactId>maven-dependency-plugin</artifactId>

                <executions>

                    <execution>

                        <id>copy-dependencies</id>

                        <phase>prepare-package</phase>

                        <goals>

                            <goal>copy-dependencies</goal>

                        </goals>

                        <configuration>

                            <outputDirectory>

                                ${project.build.directory}/libs

                            </outputDirectory>

                        </configuration>

                    </execution>

                </executions>

            </plugin>

 

            <plugin>

                <groupId>org.apache.maven.plugins</groupId>

                <artifactId>maven-jar-plugin</artifactId>

                <configuration>

                    <archive>

                        <manifest>

                            <addClasspath>true</addClasspath>

                            <classpathPrefix>libs/</classpathPrefix>

                            <mainClass>com.dalongplugin.bootstrap.BootstrapApplication</mainClass>

                        </manifest>

                    </archive>

                </configuration>

            </plugin>

        </plugins>

    </build>

 

</project>

• 入口代码

package com.dalongplugin.bootstrap;

 

import com.dalongpluginb.PluginContract;

import org.springframework.boot.ApplicationRunner;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.context.annotation.Bean;

import org.springframework.plugin.core.PluginRegistry;

import org.springframework.plugin.core.config.EnablePluginRegistries;

 

// 通过scanBasePackages 配置需要进行的包扫描，间接解决插件加载的问题

@SpringBootApplication(scanBasePackages = {"com.dalongpluginb","com.dalongplugin.bootstrap","com.dalongplugina"})

// 进行插件扫描

@EnablePluginRegistries(PluginContract.class)

public class BootstrapApplication {

 

    public static void main(String[] args) {

        SpringApplication.run(BootstrapApplication.class, args);

    }

    // ApplicationRunner 启动之后进行插件的调用，主要是测试

    @Bean

    public ApplicationRunner runner(PluginRegistry<PluginContract,String> plugins) {

        return args -> {

            plugins.forEach(plugin -> {

                System.out.println(plugin.message("hello"));

            });

        };

    }

}

使用效果

因为默认本地开发插件都加载了（maven 配置了），因为我们使用的是通过外部classpath 模式，所以可以随时进行插件的添加以及移除

• 构建

mvn clean package

• bootstrap 效果

├── bootstrap-0.0.1-SNAPSHOT.jar

└── libs

    ├── accessors-smart-1.2.jar

    ├── android-json-0.0.20131108.vaadin1.jar

    ├── apiguardian-api-1.1.0.jar

    ├── asm-5.0.4.jar

    ├── assertj-core-3.18.1.jar

    ├── byte-buddy-1.10.19.jar

    ├── byte-buddy-agent-1.10.19.jar

    ├── hamcrest-2.2.jar

    ├── jackson-annotations-2.11.4.jar

    ├── jackson-core-2.11.4.jar

    ├── jackson-databind-2.11.4.jar

    ├── jackson-datatype-jdk8-2.11.4.jar

    ├── jackson-datatype-jsr310-2.11.4.jar

    ├── jackson-module-parameter-names-2.11.4.jar

    ├── jakarta.activation-api-1.2.2.jar

    ├── jakarta.annotation-api-1.3.5.jar

    ├── jakarta.el-3.0.3.jar

    ├── jakarta.xml.bind-api-2.3.3.jar

    ├── json-path-2.4.0.jar

    ├── json-smart-2.3.jar

    ├── jsonassert-1.5.0.jar

    ├── jul-to-slf4j-1.7.30.jar

    ├── junit-jupiter-5.7.0.jar

    ├── junit-jupiter-api-5.7.0.jar

    ├── junit-jupiter-engine-5.7.0.jar

    ├── junit-jupiter-params-5.7.0.jar

    ├── junit-platform-commons-1.7.0.jar

    ├── junit-platform-engine-1.7.0.jar

    ├── log4j-api-2.13.3.jar

    ├── log4j-to-slf4j-2.13.3.jar

    ├── logback-classic-1.2.3.jar

    ├── logback-core-1.2.3.jar

    ├── mockito-core-3.6.28.jar

    ├── mockito-junit-jupiter-3.6.28.jar

    ├── objenesis-3.1.jar

    ├── opentest4j-1.2.0.jar

    ├── plugin_a-1.0-SNAPSHOT.jar

    ├── plugin_b-1.0-SNAPSHOT.jar

    ├── plugin_interface-1.0-SNAPSHOT.jar

    ├── slf4j-api-1.7.30.jar

    ├── snakeyaml-1.27.jar

    ├── spring-aop-5.3.3.jar

    ├── spring-beans-5.3.3.jar

    ├── spring-boot-2.4.2.jar

    ├── spring-boot-autoconfigure-2.4.2.jar

    ├── spring-boot-starter-2.4.2.jar

    ├── spring-boot-starter-json-2.4.2.jar

    ├── spring-boot-starter-logging-2.4.2.jar

    ├── spring-boot-starter-test-2.4.2.jar

    ├── spring-boot-starter-tomcat-2.4.2.jar

    ├── spring-boot-starter-web-2.4.2.jar

    ├── spring-boot-test-2.4.2.jar

    ├── spring-boot-test-autoconfigure-2.4.2.jar

    ├── spring-context-5.3.3.jar

    ├── spring-core-5.3.3.jar

    ├── spring-expression-5.3.3.jar

    ├── spring-jcl-5.3.3.jar

    ├── spring-plugin-core-2.0.0.RELEASE.jar

    ├── spring-plugin-metadata-2.0.0.RELEASE.jar

    ├── spring-test-5.3.3.jar

    ├── spring-web-5.3.3.jar

    ├── spring-webmvc-5.3.3.jar

    ├── tomcat-embed-core-9.0.41.jar

    ├── tomcat-embed-websocket-9.0.41.jar

    └── xmlunit-core-2.7.0.jar

默认运行效果

移除一个插件的效果

说明

实际上目前也是有不少缺陷的，比如类java，外部jar 加载，以及类隔离的一些问题，同时也缺少维护了，但是对于简单项目还是很不错的，可以使用

参考资料

https://github.com/spring-projects/spring-plugin
https://github.com/rongfengliang/spring-plugin-learning