groovy是一種動態腳本語言，適用于一些可變、和規則配置性的需求，目前Spring提供ScriptSource介面，支持兩種型別，一種是

ResourceScriptSource，另一種是 StaticScriptSource，但是有的場景我們需要把groovy代碼放進DB中，所以我們需要擴展這個，

ResourceScriptSource：在 resources 下面寫groovy類

StaticScriptSource：把groovy類代碼放進XML里

DatabaseScriptSource：把groovy類代碼放進資料庫中

工程模塊為：

ResourceScriptSource

groovy的pom

        <dependency>
            <artifactId>groovy-all</artifactId>
            <groupId>org.codehaus.groovy</groupId>
            <version>2.1.9</version>
            <scope>compile</scope>
        </dependency>

HelloService介面

package com.maple.resource.groovy;

/**
 * @author: maple
 * @version: HelloService.java, v 0.1 2020年09月25日 21:26 maple Exp $
 */
public interface HelloService {

    String sayHello();
}

resources下面建groovy實作類

package com.maple.resource.groovy

class HelloServiceImpl implements HelloService {

    String name;

    @Override
    String sayHello() {
        return "Hello $name. Welcome to resource in Groovy.";
    }
}

在spring-groovy.xml中配置

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

    <lang:groovy id="helloService" script-source="classpath:groovy/HelloServiceImpl.groovy">
        <lang:property name="name" value="maple"></lang:property>
    </lang:groovy>

</beans>

主類 GroovyResourceApplication

package com.maple.resource;

import com.maple.resource.groovy.HelloService;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.support.ClassPathXmlApplicationContext;

@SpringBootApplication
public class GroovyResourceApplication {

    public static void main(String[] args) {

        //SpringApplication.run(GroovyResourceApplication.class, args);

        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("spring-groovy.xml");

        HelloService bean = context.getBean(HelloService.class);

        String sayHello = bean.sayHello();

        System.out.println(sayHello);
    }

}

啟動并測驗

StaticScriptSource

groovy的pom

        <dependency>
            <artifactId>groovy-all</artifactId>
            <groupId>org.codehaus.groovy</groupId>
            <version>2.1.9</version>
            <scope>compile</scope>
        </dependency>

HelloService介面

package com.maple.groovy.staticscript.groovy;

/**
 * @author: maple
 * @version: HelloService.java, v 0.1 2020年09月25日 21:26 maple Exp $
 */
public interface HelloService {

    String sayHello();
}

在spring-groovy.xml中配置具體的實作類

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

    <lang:groovy id="helloService">

        <lang:inline-script>

            import com.maple.groovy.staticscript.groovy.HelloService

            class HelloServiceImpl implements HelloService {

                String name;

                @Override
                String sayHello() {
                    return "Hello $name. Welcome to static script in Groovy.";
                }
            }

        </lang:inline-script>

        <lang:property name="name" value="maple"/>

    </lang:groovy>

</beans>

主類 GroovyStaticscriptApplication

package com.maple.groovy.staticscript;

import com.maple.groovy.staticscript.groovy.HelloService;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.support.ClassPathXmlApplicationContext;

@SpringBootApplication
public class GroovyStaticscriptApplication {

    public static void main(String[] args) {

        //SpringApplication.run(GroovyStaticscriptApplication.class, args);

        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("spring-groovy.xml");

        HelloService bean = context.getBean(HelloService.class);

        String sayHello = bean.sayHello();

        System.out.println(sayHello);
    }

}

啟動并測驗

DatabaseScriptSource

下面我們先建表，把基本作業做完，這里我使用mybatisplus，dao、service等代碼省略

CREATE TABLE `groovy_script` (
`id` BIGINT ( 20 ) NOT NULL AUTO_INCREMENT,
`script_name` VARCHAR ( 64 ) NOT NULL COMMENT 'script name',
`script_content` text NOT NULL COMMENT 'script content',
`status` VARCHAR ( 16 ) NOT NULL DEFAULT 'ENABLE' COMMENT 'ENABLE/DISENABLE',
`extend_info` VARCHAR ( 4096 ) DEFAULT NULL,
`created_time` TIMESTAMP ( 6 ) NOT NULL DEFAULT CURRENT_TIMESTAMP ( 6 ),
`modified_time` TIMESTAMP ( 6 ) NOT NULL DEFAULT CURRENT_TIMESTAMP ( 6 ) ON UPDATE CURRENT_TIMESTAMP ( 6 ),
PRIMARY KEY ( `id` ) 
) ENGINE = INNODB AUTO_INCREMENT = 1 DEFAULT CHARSET = utf8mb4 COMMENT = 'groovy script';

INSERT INTO `gane-platform`.`groovy_script`(`id`, `script_name`, `script_content`, `status`, `extend_info`, `created_time`, `modified_time`) VALUES (1, 'helloService', 'package com.maple.resource.groovy\r\n\r\nimport com.maple.database.groovy.HelloService\r\n\r\npublic class HelloServiceImpl implements HelloService {\r\n\r\n    @Override\r\n    String sayHello(String name) {\r\n        return \"Hello \"+name+\". Welcome to database in Groovy.\";\r\n    }\r\n}', 'ENABLE', NULL, '2020-09-26 17:16:36.477818', '2020-09-27 08:23:10.790553');

方法一：

1、實時讀取DB里的groovy腳本檔案

2、利用GroovyClassLoader去編譯腳本檔案

3、把class物件注入成Spring bean

4、反射呼叫腳本的方法

package com.maple.database.controller;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.maple.database.entity.GroovyScript;
import com.maple.database.groovy.SpringContextUtils;
import com.maple.database.service.GroovyScriptService;
import groovy.lang.GroovyClassLoader;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 * @author: maple
 * @version: GroovyController.java, v 0.1 2020年09月26日 17:18 maple Exp $
 */
@RestController
public class GroovyController {

    @Resource
    private GroovyScriptService groovyScriptService;

    @GetMapping("/groovyTest")
    private String groovyTest() throws IllegalAccessException, InstantiationException, InvocationTargetException, NoSuchMethodException {

        GroovyScript groovyScript = groovyScriptService.getOne(new QueryWrapper<GroovyScript>()
                .eq("script_name", "helloService").eq("status", "ENABLE"));

        System.out.println(groovyScript.getScriptContent());

        Class clazz = new GroovyClassLoader().parseClass(groovyScript.getScriptContent());

        Object o = clazz.newInstance();

        SpringContextUtils.autowireBean(o);

        Method method = clazz.getMethod("sayHello", String.class);

        return (String) method.invoke(o, "maple");
    }
}

package com.maple.database.groovy;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

/**
 * @author: maple
 * @version: SpringContextUtils.java, v 0.1 2020年09月26日 17:29 maple Exp $
 */
@Component
public class SpringContextUtils implements ApplicationContextAware {

    static ApplicationContext context;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        SpringContextUtils.context = applicationContext;
    }

    public static void autowireBean(Object bean) {
        context.getAutowireCapableBeanFactory().autowireBean(bean);
    }

    public static ApplicationContext getContext() {
        return context;
    }

    public static <T> T getBean(Class<T> clazz) {
        return context.getBean(clazz);

    }

    public static <T> T getBean(String name) {
        return (T) context.getBean(name);

    }
}

啟動測驗結果為：

總結：

優點：實時讀取DB里的腳本，當腳本更改時，可以直接修改DB，對代碼無侵入

缺點：每次都要查詢DB，反射呼叫代碼寫死了

方法二：

1、我們模仿groovy-resource的思路，resource的XML配置是下面這樣的

<lang:groovy id="helloService" script-source="classpath:groovy/HelloServiceImpl.groovy" />

所以，我們可以把DatabaseScriptSource的XML保存成這種格式

<lang:groovy id="helloService" script-source="database:helloService"/>

2、然后模仿Spring保存成XML格式的document的思路，我們也把groovy保存成XML格式的document，放進記憶體里

3、groovy的關鍵處理類是ScriptFactoryPostProcessor，當 Spring 裝載應用程式背景關系時，它首先創建工廠 bean（例如 GroovyScriptFactory bean），然后，執行ScriptFactoryPostProcessor bean，用實際的腳本物件替換所有的工廠 bean，例如，我們本次測驗的配置產生一個名為 helloService 的 bean，它的型別是groovierspring.GroovyHelloService，（如果啟用 Spring 中的 debug 級日志記錄，并觀察應用程式背景關系的啟動，將會看到 Spring 首先創建一個名為 scriptFactory.helloService 的工廠 bean，然后 ScriptFactoryPostProcessor 從該工廠 bean 創建 helloService bean），

我們發現ScriptFactoryPostProcessor這個類中，有getScriptSource這個方法，該方法里有convertToScriptSource方法

在convertToScriptSource這個方法中，他默認支持我們前面說過的static script和resource兩種型別，但是現在我們新增了一種database型別，所以我們需要重寫該方法，其他的作業都一樣，交給ScriptFactoryPostProcessor幫我們去處理，

package com.maple.database.manage;

import com.maple.database.groovy.DatabaseScriptSource;
import org.apache.commons.lang3.StringUtils;
import org.springframework.core.io.ResourceLoader;
import org.springframework.scripting.ScriptSource;
import org.springframework.scripting.support.ResourceScriptSource;
import org.springframework.scripting.support.ScriptFactoryPostProcessor;
import org.springframework.scripting.support.StaticScriptSource;
import org.springframework.stereotype.Component;

/**
 * @author: maple
 * @version: CustomerScriptFactoryPostProcessor.java, v 0.1 2020年09月26日 20:36 maple Exp $
 */
@Component
public class CustomerScriptFactoryPostProcessor extends ScriptFactoryPostProcessor {

    @Override
    protected ScriptSource convertToScriptSource(String beanName, String scriptSourceLocator, ResourceLoader resourceLoader) {

        if (scriptSourceLocator.startsWith(INLINE_SCRIPT_PREFIX)) {
            return new StaticScriptSource(scriptSourceLocator.substring(INLINE_SCRIPT_PREFIX.length()), beanName);

        }

        if (scriptSourceLocator.startsWith(GroovyConstant.SCRIPT_SOURCE_PREFIX)) {
            return new DatabaseScriptSource(StringUtils.substringAfter(scriptSourceLocator, GroovyConstant.SCRIPT_SOURCE_PREFIX));
        }

        return new ResourceScriptSource(resourceLoader.getResource(scriptSourceLocator));
    }
}

但是我們也要看看ScriptFactoryPostProcessor幫我們處理的其他作業都是什么：

（1）predictBeanType：是 Spring 中從 BeanDefinition 中提取 Bean 型別的底層 API

（2）我們再來看prepareScriptBeans準備了什么

（3）scriptBeanFactory.registerBeanDefinition，向beanDefinitionMap里put鍵值對

（4）createScriptedObjectBeanDefinition

（5）Class<?> scriptedType = scriptFactory.getScriptedObjectType(scriptSource);

這句是為了拿到我們具體的實作類，也是我們的基礎，它里面就是用GroovyClassLoader去編譯我們的groovy腳本內容，并回傳了Class<?> scriptClass我們的HelloServiceImpl

（6）ScriptSource scriptSource = getScriptSource(scriptFactoryBeanName, scriptFactory.getScriptSourceLocator());

這里首先去我們下面新增的DatabaseScriptSource里拿到groovy腳本內容，并放進map里，回傳DatabaseScriptSource

4、新增DatabaseScriptSource類

package com.maple.database.groovy;

import com.maple.database.groovy.cache.GroovyCache;
import org.springframework.scripting.ScriptSource;
import org.springframework.util.StringUtils;

import java.io.IOException;

/**
 * @author: maple
 * @version: DatabaseScriptSource.java, v 0.1 2020年09月26日 15:37 maple Exp $
 */
public final class DatabaseScriptSource implements ScriptSource {

    /**
     * 腳本名稱
     */
    private String scriptName;

    /**
     * 建構式
     *
     * @param scriptName
     */
    public DatabaseScriptSource(String scriptName) {
        this.scriptName = scriptName;
    }

    @Override
    public String getScriptAsString() throws IOException {

        return GroovyCache.getByName(scriptName).getGroovyContent();
    }

    @Override
    public boolean isModified() {
        return false;
    }

    @Override
    public String suggestedClassName() {
        return StringUtils.stripFilenameExtension(this.scriptName);
    }
}

5、把我們的CustomerScriptFactoryPostProcessor放進Spring的List<BeanPostProcessor>中

這樣的話，我們就能從Spring容器中獲取helloService的bean實體了，測驗：

package com.maple.database.controller;

import com.maple.database.groovy.HelloService;
import com.maple.database.groovy.SpringContextUtils;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author: maple
 * @version: GroovyController.java, v 0.1 2020年09月26日 17:18 maple Exp $
 */
@RestController
public class NewGroovyController {

    @GetMapping("/newGroovyTest")
    private String newGroovyTest() {

        HelloService helloService = SpringContextUtils.getBean("helloService");

        String hello = helloService.sayHello("maple");

        System.out.println(hello);

        return hello;
    }
}

總結：

優點：專案初始化的時候，就把DB里的groovy腳本讀取到，放進本次快取里，并交給Spring管理，減少與DB的互動次數；沒有硬編碼，擴展性更好，

缺點：當DB里的groovy腳本檔案需要修改時，我們改完之后不能立即生效，需要重啟工程或者重繪本次快取，再次放進Spring容器里才行

附上核心處理類：GroovyDynamicLoader，部分代碼不全的話，可以私信我

package com.maple.database.manage;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.maple.database.entity.GroovyScript;
import com.maple.database.groovy.cache.GroovyCache;
import com.maple.database.groovy.cache.GroovyInfo;
import com.maple.database.service.GroovyScriptService;
import groovy.lang.GroovyClassLoader;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.xml.ResourceEntityResolver;
import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.annotation.Configuration;
import org.springframework.util.Assert;
import org.springframework.util.CollectionUtils;

import javax.annotation.Resource;
import java.util.List;
import java.util.stream.Collectors;

/**
 * @author: maple
 * @version: GroovyDynamicLoader.java, v 0.1 2020年09月26日 20:00 maple Exp $
 */
@Configuration
public class GroovyDynamicLoader implements ApplicationContextAware, InitializingBean {


    private ConfigurableApplicationContext applicationContext;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = (ConfigurableApplicationContext) applicationContext;
    }

    @Resource
    private GroovyScriptService groovyScriptService;

    private static final GroovyClassLoader groovyClassLoader = new GroovyClassLoader(GroovyDynamicLoader.class.getClassLoader());


    @Override
    public void afterPropertiesSet() throws Exception {
        init();
    }

    private void init() {

        List<GroovyScript> groovyScripts = groovyScriptService.list(new QueryWrapper<GroovyScript>().eq("status", "ENABLE"));

        List<GroovyInfo> groovyInfos = groovyScripts.stream().map(groovyScript -> {
            GroovyInfo groovyInfo = new GroovyInfo();
            groovyInfo.setClassName(groovyScript.getScriptName());
            groovyInfo.setGroovyContent(groovyScript.getScriptContent());
            return groovyInfo;
        }).collect(Collectors.toList());

        if (CollectionUtils.isEmpty(groovyInfos)) {
            return;
        }

        ConfigurationXMLWriter config = new ConfigurationXMLWriter();

        addConfiguration(config, groovyInfos);

        GroovyCache.put2map(groovyInfos);

        loadBeanDefinitions(config);
    }

    private void addConfiguration(ConfigurationXMLWriter config, List<GroovyInfo> groovyInfos) {
        for (GroovyInfo groovyInfo : groovyInfos) {
            writeBean(config, groovyInfo);
        }
    }

    private void writeBean(ConfigurationXMLWriter config, GroovyInfo groovyInfo) {

        if (checkSyntax(groovyInfo)) {

            DynamicBean bean = composeDynamicBean(groovyInfo);

            config.write(GroovyConstant.SPRING_TAG, bean);
        }
    }

    private boolean checkSyntax(GroovyInfo groovyInfo) {

        try {
            groovyClassLoader.parseClass(groovyInfo.getGroovyContent());
        } catch (Exception e) {
            return false;
        }

        return true;
    }

    private DynamicBean composeDynamicBean(GroovyInfo groovyInfo) {

        DynamicBean bean = new DynamicBean();

        String scriptName = groovyInfo.getClassName();

        Assert.notNull(scriptName, "parser className cannot be empty!");

        //設定bean的屬性，這里只有id和script-source，
        bean.put("id", scriptName);
        bean.put("script-source", GroovyConstant.SCRIPT_SOURCE_PREFIX + scriptName);

        return bean;
    }

    private void loadBeanDefinitions(ConfigurationXMLWriter config) {

        String contextString = config.getContent();

        if (StringUtils.isBlank(contextString)) {
            return;
        }

        XmlBeanDefinitionReader beanDefinitionReader = new XmlBeanDefinitionReader((BeanDefinitionRegistry) this.applicationContext.getBeanFactory());
        beanDefinitionReader.setResourceLoader(this.applicationContext);
        beanDefinitionReader.setBeanClassLoader(applicationContext.getClassLoader());
        beanDefinitionReader.setEntityResolver(new ResourceEntityResolver(this.applicationContext));
        beanDefinitionReader.loadBeanDefinitions(new InMemoryResource(contextString));

        String[] postProcessorNames = applicationContext.getBeanFactory().getBeanNamesForType(CustomerScriptFactoryPostProcessor.class, true, false);

        for (String postProcessorName : postProcessorNames) {
            applicationContext.getBeanFactory().addBeanPostProcessor((BeanPostProcessor) applicationContext.getBean(postProcessorName));
        }
    }

}

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Spring中集成Groovy的四種方式

ResourceScriptSource

StaticScriptSource

DatabaseScriptSource

方法一：

總結：

方法二：

總結：