springboot运行时新增/更新外部接口的实现方法

package com.rdpaas.dynamic.core;


import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;
import java.security.AccessController;
import java.security.PrivilegedExceptionAction;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;


/**
 * 动态加载外部jar包的自定义类加载器
 * @author rongdi
 * @date 2021-03-06
 * @blog https://www.cnblogs.com/rongdi
 */
public class ModuleClassLoader extends URLClassLoader {

  private Logger logger = LoggerFactory.getLogger(ModuleClassLoader.class);

  private final static String CLASS_SUFFIX = ".class";

  private final static String XML_SUFFIX = ".xml";

  private final static String MAPPER_SUFFIX = "mapper/";

  //属于本类加载器加载的jar包
  private JarFile jarFile;

  private Map<String, byte[]> classBytesMap = new HashMap<>();

  private Map<String, Class<?>> classesMap = new HashMap<>();

  private Map<String, byte[]> xmlBytesMap = new HashMap<>();

  public ModuleClassLoader(ClassLoader classLoader, URL... urls) {
    super(urls, classLoader);
    URL url = urls[0];
    String path = url.getPath();
    try {
      jarFile = new JarFile(path);
    } catch (IOException e) {
      e.printStackTrace();
    }
  }

  @Override
  protected Class<?> findClass(String name) throws ClassNotFoundException {
    byte[] buf = classBytesMap.get(name);
    if (buf == null) {
      return super.findClass(name);
    }
    if(classesMap.containsKey(name)) {
      return classesMap.get(name);
    }
    /**
     * 这里应该算是骚操作了，我不知道市面上有没有人这么做过，反正我是想了好久，遇到各种因为spring要生成代理对象
     * 在他自己的AppClassLoader找不到原对象导致的报错，注意如果你限制你的扩展包你不会有AOP触碰到的类或者@Transactional这种
     * 会产生代理的类，那么其实你不用这么骚，直接在这里调用defineClass把字节码装载进去就行了，不会有什么问题，最多也就是
     * 在加载mybatis的xml那里前后加三句话，
     * 1、获取并使用一个变量保存当前线程类加载器
     * 2、将自定义类加载器设置到当前线程类加载器
     * 3、还原当前线程类加载器为第一步保存的类加载器
     * 这样之后mybatis那些xml里resultType，resultMap之类的需要访问扩展包的Class的就不会报错了。
     * 不过直接用现在这种骚操作，更加一劳永逸，不会有mybatis的问题了
     */
    return loadClass(name,buf);
  }

  /**
   * 使用反射强行将类装载的归属给当前类加载器的父类加载器也就是AppClassLoader，如果报ClassNotFoundException
   * 则递归装载
   * @param name
   * @param bytes
   * @return
   */
  private Class<?> loadClass(String name, byte[] bytes) throws ClassNotFoundException {

    Object[] args = new Object[]{name, bytes, 0, bytes.length};
    try {
      /**
       * 拿到当前类加载器的parent加载器AppClassLoader
       */
      ClassLoader parent = this.getParent();
      /**
       * 首先要明确反射是万能的，仿造org.springframework.cglib.core.ReflectUtils的写法，强行获取被保护
       * 的方法defineClass的对象，然后调用指定类加载器的加载字节码方法，强行将加载归属塞给它，避免被spring的AOP或者@Transactional
       * 触碰到的类需要生成代理对象，而在AppClassLoader下加载不到外部的扩展类而报错，所以这里强行将加载外部扩展包的类的归属给
       * AppClassLoader，让spring的cglib生成代理对象时可以加载到原对象
       */
      Method classLoaderDefineClass = (Method) AccessController.doPrivileged(new PrivilegedExceptionAction() {
        @Override
        public Object run() throws Exception {
          return ClassLoader.class.getDeclaredMethod("defineClass",
              String.class, byte[].class, Integer.TYPE, Integer.TYPE);
        }
      });
      if(!classLoaderDefineClass.isAccessible()) {
        classLoaderDefineClass.setAccessible(true);
      }
      return (Class<?>)classLoaderDefineClass.invoke(parent,args);
    } catch (Exception e) {
      if(e instanceof InvocationTargetException) {
        String message = ((InvocationTargetException) e).getTargetException().getCause().toString();
        /**
         * 无奈，明明ClassNotFoundException是个异常，非要抛个InvocationTargetException，导致
         * 我这里一个不太优雅的判断
         */
        if(message.startsWith("java.lang.ClassNotFoundException")) {
          String notClassName = message.split(":")[1];
          if(StringUtils.isEmpty(notClassName)) {
            throw new ClassNotFoundException(message);
          }
          notClassName = notClassName.trim();
          byte[] bytes1 = classBytesMap.get(notClassName);
          if(bytes1 == null) {
            throw new ClassNotFoundException(message);
          }
          /**
           * 递归装载未找到的类
           */
          Class<?> notClass = loadClass(notClassName, bytes1);
          if(notClass == null) {
            throw new ClassNotFoundException(message);
          }
          classesMap.put(notClassName,notClass);
          return loadClass(name,bytes);
        }
      } else {
        logger.error("",e);
      }
    }
    return null;
  }

  public Map<String,byte[]> getXmlBytesMap() {
    return xmlBytesMap;
  }


  /**
   * 方法描述 初始化类加载器，保存字节码
   */
  public Map<String, Class> load() {

    Map<String, Class> cacheClassMap = new HashMap<>();

    //解析jar包每一项
    Enumeration<JarEntry> en = jarFile.entries();
    InputStream input = null;
    try {
      while (en.hasMoreElements()) {
        JarEntry je = en.nextElement();
        String name = je.getName();
        //这里添加了路径扫描限制
        if (name.endsWith(CLASS_SUFFIX)) {
          String className = name.replace(CLASS_SUFFIX, "").replaceAll("/", ".");
          input = jarFile.getInputStream(je);
          ByteArrayOutputStream baos = new ByteArrayOutputStream();
          int bufferSize = 4096;
          byte[] buffer = new byte[bufferSize];
          int bytesNumRead = 0;
          while ((bytesNumRead = input.read(buffer)) != -1) {
            baos.write(buffer, 0, bytesNumRead);
          }
          byte[] classBytes = baos.toByteArray();
          classBytesMap.put(className, classBytes);
        } else if(name.endsWith(XML_SUFFIX) && name.startsWith(MAPPER_SUFFIX)) {
          input = jarFile.getInputStream(je);
          ByteArrayOutputStream baos = new ByteArrayOutputStream();
          int bufferSize = 4096;
          byte[] buffer = new byte[bufferSize];
          int bytesNumRead = 0;
          while ((bytesNumRead = input.read(buffer)) != -1) {
            baos.write(buffer, 0, bytesNumRead);
          }
          byte[] xmlBytes = baos.toByteArray();
          xmlBytesMap.put(name, xmlBytes);
        }
      }
    } catch (IOException e) {
      logger.error("",e);
    } finally {
      if (input != null) {
        try {
          input.close();
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
    }

    //将jar中的每一个class字节码进行Class载入
    for (Map.Entry<String, byte[]> entry : classBytesMap.entrySet()) {
      String key = entry.getKey();
      Class<?> aClass = null;
      try {
        aClass = loadClass(key);
      } catch (ClassNotFoundException e) {
        logger.error("",e);
      }
      cacheClassMap.put(key, aClass);
    }
    return cacheClassMap;

  }

  public Map<String, byte[]> getClassBytesMap() {
    return classBytesMap;
  }
}

package com.rdpaas.dynamic.core;

import org.apache.ibatis.builder.xml.XMLMapperBuilder;
import org.apache.ibatis.builder.xml.XMLMapperEntityResolver;
import org.apache.ibatis.executor.ErrorContext;
import org.apache.ibatis.executor.keygen.SelectKeyGenerator;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.parsing.XNode;
import org.apache.ibatis.parsing.XPathParser;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.mapper.MapperFactoryBean;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.ByteArrayInputStream;
import java.lang.reflect.Field;
import java.util.*;

/**
 * mybatis的mapper.xml和@Mapper加载类
 * @author rongdi
 * @date 2021-03-06
 * @blog https://www.cnblogs.com/rongdi
 */
public class MapperLoader {

  private Logger logger = LoggerFactory.getLogger(MapperLoader.class);

  private Configuration configuration;

  /**
   * 刷新外部mapper，包括文件和@Mapper修饰的接口
   * @param sqlSessionFactory
   * @param xmlBytesMap
   * @return
   */
  public Map<String,Object> refresh(SqlSessionFactory sqlSessionFactory, Map<String, byte[]> xmlBytesMap) {
    Configuration configuration = sqlSessionFactory.getConfiguration();
    this.configuration = configuration;

    /**
     * 这里用来区分mybatis-plus和mybatis，mybatis-plus的Configuration是继承自mybatis的子类
     */
    boolean isSupper = configuration.getClass().getSuperclass() == Configuration.class;
    Map<String,Object> mapperMap = new HashMap<>();
    try {
      /**
       * 遍历外部传入的xml字节码map
       */
      for(Map.Entry<String,byte[]> entry:xmlBytesMap.entrySet()) {
        String resource = entry.getKey();
        byte[] bytes = entry.getValue();
        /**
         * 使用反射强行拿出configuration中的loadedResources属性
         */
        Field loadedResourcesField = isSupper
            ? configuration.getClass().getSuperclass().getDeclaredField("loadedResources")
            : configuration.getClass().getDeclaredField("loadedResources");
        loadedResourcesField.setAccessible(true);
        Set loadedResourcesSet = ((Set) loadedResourcesField.get(configuration));
        /**
         * 加载mybatis中的xml
         */
        XPathParser xPathParser = new XPathParser(new ByteArrayInputStream(bytes), true, configuration.getVariables(),
            new XMLMapperEntityResolver());
        /**
         * 解析mybatis的xml的根节点，
         */
        XNode context = xPathParser.evalNode("/mapper");
        /**
         * 拿到namespace，namespace就是指Mapper接口的全限定名
         */
        String namespace = context.getStringAttribute("namespace");
        Field field = configuration.getMapperRegistry().getClass().getDeclaredField("knownMappers");
        field.setAccessible(true);

        /**
         * 拿到存放Mapper接口和对应代理子类的映射map，
         */
        Map mapConfig = (Map) field.get(configuration.getMapperRegistry());
        /**
         * 拿到Mapper接口对应的class对象
         */
        Class nsClass = Resources.classForName(namespace);

        /**
         * 先删除各种
         */
        mapConfig.remove(nsClass);
        loadedResourcesSet.remove(resource);
        configuration.getCacheNames().remove(namespace);

        /**
         * 清掉namespace下各种缓存
         */
        cleanParameterMap(context.evalNodes("/mapper/parameterMap"), namespace);
        cleanResultMap(context.evalNodes("/mapper/resultMap"), namespace);
        cleanKeyGenerators(context.evalNodes("insert|update|select|delete"), namespace);
        cleanSqlElement(context.evalNodes("/mapper/sql"), namespace);

        /**
         * 加载并解析对应xml
         */
        XMLMapperBuilder xmlMapperBuilder = new XMLMapperBuilder(new ByteArrayInputStream(bytes),
            sqlSessionFactory.getConfiguration(), resource,
            sqlSessionFactory.getConfiguration().getSqlFragments());
        xmlMapperBuilder.parse();

        /**
         * 构造MapperFactoryBean，注意这里一定要传入sqlSessionFactory,
         * 这块逻辑通过debug源码试验了很久
         */
        MapperFactoryBean mapperFactoryBean = new MapperFactoryBean(nsClass);
        mapperFactoryBean.setSqlSessionFactory(sqlSessionFactory);
        /**
         * 放入map，返回出去给ModuleApplication去加载
         */
        mapperMap.put(namespace,mapperFactoryBean);
        logger.info("refresh: '" + resource + "', success!");

      }
      return mapperMap;
    } catch (Exception e) {
      logger.error("refresh error",e.getMessage());
    } finally {
      ErrorContext.instance().reset();
    }
    return null;
  }

  /**
   * 清理parameterMap
   *
   * @param list
   * @param namespace
   */
  private void cleanParameterMap(List<XNode> list, String namespace) {
    for (XNode parameterMapNode : list) {
      String id = parameterMapNode.getStringAttribute("id");
      configuration.getParameterMaps().remove(namespace + "." + id);
    }
  }

  /**
   * 清理resultMap
   *
   * @param list
   * @param namespace
   */
  private void cleanResultMap(List<XNode> list, String namespace) {
    for (XNode resultMapNode : list) {
      String id = resultMapNode.getStringAttribute("id", resultMapNode.getValueBasedIdentifier());
      configuration.getResultMapNames().remove(id);
      configuration.getResultMapNames().remove(namespace + "." + id);
      clearResultMap(resultMapNode, namespace);
    }
  }

  private void clearResultMap(XNode xNode, String namespace) {
    for (XNode resultChild : xNode.getChildren()) {
      if ("association".equals(resultChild.getName()) || "collection".equals(resultChild.getName())
          || "case".equals(resultChild.getName())) {
        if (resultChild.getStringAttribute("select") == null) {
          configuration.getResultMapNames()
              .remove(resultChild.getStringAttribute("id", resultChild.getValueBasedIdentifier()));
          configuration.getResultMapNames().remove(namespace + "."
              + resultChild.getStringAttribute("id", resultChild.getValueBasedIdentifier()));
          if (resultChild.getChildren() != null && !resultChild.getChildren().isEmpty()) {
            clearResultMap(resultChild, namespace);
          }
        }
      }
    }
  }

  /**
   * 清理selectKey
   *
   * @param list
   * @param namespace
   */
  private void cleanKeyGenerators(List<XNode> list, String namespace) {
    for (XNode context : list) {
      String id = context.getStringAttribute("id");
      configuration.getKeyGeneratorNames().remove(id + SelectKeyGenerator.SELECT_KEY_SUFFIX);
      configuration.getKeyGeneratorNames().remove(namespace + "." + id + SelectKeyGenerator.SELECT_KEY_SUFFIX);

      Collection<MappedStatement> mappedStatements = configuration.getMappedStatements();
      List<MappedStatement> objects = new ArrayList<>();
      Iterator<MappedStatement> it = mappedStatements.iterator();
      while (it.hasNext()) {
        Object object = it.next();
        if (object instanceof MappedStatement) {
          MappedStatement mappedStatement = (MappedStatement) object;
          if (mappedStatement.getId().equals(namespace + "." + id)) {
            objects.add(mappedStatement);
          }
        }
      }
      mappedStatements.removeAll(objects);
    }
  }

  /**
   * 清理sql节点缓存
   *
   * @param list
   * @param namespace
   */
  private void cleanSqlElement(List<XNode> list, String namespace) {
    for (XNode context : list) {
      String id = context.getStringAttribute("id");
      configuration.getSqlFragments().remove(id);
      configuration.getSqlFragments().remove(namespace + "." + id);
    }
  }

}

package com.rdpaas.dynamic.core;

import com.rdpaas.dynamic.utils.ReflectUtil;
import com.rdpaas.dynamic.utils.SpringUtil;
import org.apache.ibatis.session.SqlSessionFactory;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.plugin.core.PluginRegistry;
import org.springframework.util.MultiValueMap;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.mvc.method.RequestMappingInfo;
import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.builders.ResponseMessageBuilder;
import springfox.documentation.schema.ModelRef;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.service.Contact;
import springfox.documentation.service.ResponseMessage;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spi.service.DocumentationPlugin;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.spring.web.plugins.DocumentationPluginsBootstrapper;
import springfox.documentation.spring.web.plugins.DocumentationPluginsManager;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.net.URL;
import java.util.*;

/**
 * 基于spring的应用上下文提供一些工具方法
 * @author rongdi
 * @date 2021-03-06
 * @blog https://www.cnblogs.com/rongdi
 */
public class ModuleApplication {

  private final static String SINGLETON = "singleton";

  private final static String DYNAMIC_DOC_PACKAGE = "dynamic.swagger.doc.package";

  private Set<RequestMappingInfo> extMappingInfos = new HashSet<>();

  private ApplicationContext applicationContext;

  /**
   * 使用spring上下文拿到指定beanName的对象
   */
  public <T> T getBean(String beanName) {
    return (T) ((ConfigurableApplicationContext) applicationContext).getBeanFactory().getBean(beanName);
  }

  /**
   * 使用spring上下文拿到指定类型的对象
   */
  public <T> T getBean(Class<T> clazz) {
    return (T) ((ConfigurableApplicationContext) applicationContext).getBeanFactory().getBean(clazz);
  }

  /**
   * 加载一个外部扩展jar，包括springmvc接口资源，mybatis的@mapper和mapper.xml和spring bean等资源
   * @param url jar url
   * @param applicationContext spring context
   * @param sqlSessionFactory mybatis的session工厂
   */
  public void reloadJar(URL url, ApplicationContext applicationContext,SqlSessionFactory sqlSessionFactory) throws Exception {
    this.applicationContext = applicationContext;
    URL[] urls = new URL[]{url};
    /**
     * 这里实际上是将spring的ApplicationContext的类加载器当成parent传给了自定义类加载器，很明自定义的子类加载器自己加载
     * 的类，parent类加载器直接是获取不到的，所以在自定义类加载器做了特殊的骚操作
     */
    ModuleClassLoader moduleClassLoader = new ModuleClassLoader(applicationContext.getClassLoader(), urls);
    /**
     * 使用模块类加载器加载url资源的jar包，直接返回类的全限定名和Class对象的映射，这些Class对象是
     * jar包里所有.class结尾的文件加载后的结果,同时mybatis的xml加载后，无奈的放入了
     * moduleClassLoader.getXmlBytesMap()，不是很优雅
     */
    Map<String, Class> classMap = moduleClassLoader.load();

    MapperLoader mapperLoader = new MapperLoader();

    /**
     * 刷新mybatis的xml和Mapper接口资源，Mapper接口其实就是xml的namespace
     */
    Map<String, Object> extObjMap = mapperLoader.refresh(sqlSessionFactory, moduleClassLoader.getXmlBytesMap());
    /**
     * 将各种资源放入spring容器
     */
    registerBeans(applicationContext, classMap, extObjMap);
  }

  /**
   * 装载bean到spring中
   *
   * @param applicationContext
   * @param cacheClassMap
   */
  public void registerBeans(ApplicationContext applicationContext, Map<String, Class> cacheClassMap,Map<String,Object> extObjMap) throws Exception {
    /**
     * 将applicationContext转换为ConfigurableApplicationContext
     */
    ConfigurableApplicationContext configurableApplicationContext = (ConfigurableApplicationContext) applicationContext;
    /**
     * 获取bean工厂并转换为DefaultListableBeanFactory
     */
    DefaultListableBeanFactory defaultListableBeanFactory = (DefaultListableBeanFactory) configurableApplicationContext.getBeanFactory();

    /**
     * 有一些对象想给spring管理，则放入spring中，如mybatis的@Mapper修饰的接口的代理类
     */
    if(extObjMap != null && !extObjMap.isEmpty()) {
      extObjMap.forEach((beanName,obj) ->{
        /**
         * 如果已经存在，则销毁之后再注册
         */
        if(defaultListableBeanFactory.containsSingleton(beanName)) {
          defaultListableBeanFactory.destroySingleton(beanName);
        }
        defaultListableBeanFactory.registerSingleton(beanName,obj);
      });
    }

    for (Map.Entry<String, Class> entry : cacheClassMap.entrySet()) {
      String className = entry.getKey();
      Class<?> clazz = entry.getValue();
      if (SpringUtil.isSpringBeanClass(clazz)) {
        //将变量首字母置小写
        String beanName = StringUtils.uncapitalize(className);
        beanName = beanName.substring(beanName.lastIndexOf(".") + 1);
        beanName = StringUtils.uncapitalize(beanName);

        /**
         * 已经在spring容器就删了
         */
        if (defaultListableBeanFactory.containsBeanDefinition(beanName)) {
          defaultListableBeanFactory.removeBeanDefinition(beanName);
        }
        /**
         * 使用spring的BeanDefinitionBuilder将Class对象转成BeanDefinition
         */
        BeanDefinitionBuilder beanDefinitionBuilder = BeanDefinitionBuilder.genericBeanDefinition(clazz);
        BeanDefinition beanDefinition = beanDefinitionBuilder.getRawBeanDefinition();
        //设置当前bean定义对象是单利的
        beanDefinition.setScope(SINGLETON);
        /**
         * 以指定beanName注册上面生成的BeanDefinition
         */
        defaultListableBeanFactory.registerBeanDefinition(beanName, beanDefinition);
      }

    }

    /**
     * 刷新springmvc，让新增的接口生效
     */
    refreshMVC((ConfigurableApplicationContext) applicationContext);

  }

  /**
   * 刷新springMVC,这里花了大量时间调试，找不到开放的方法，只能取个巧，在更新RequestMappingHandlerMapping前先记录之前
   * 所有RequestMappingInfo，记得这里一定要copy一下，然后刷新后再记录一次，计算出差量存放在成员变量Set中，然后每次开头判断
   * 差量那里是否有内容，有就先unregiester掉
   */
  private void refreshMVC(ConfigurableApplicationContext applicationContext) throws Exception {


    Map<String, RequestMappingHandlerMapping> map = applicationContext.getBeanFactory().getBeansOfType(RequestMappingHandlerMapping.class);
    /**
     * 先拿到RequestMappingHandlerMapping对象
     */
    RequestMappingHandlerMapping mappingHandlerMapping = map.get("requestMappingHandlerMapping");

    /**
     * 重新注册mapping前先判断是否存在了，存在了就先unregister掉
     */
    if(!extMappingInfos.isEmpty()) {
      for(RequestMappingInfo requestMappingInfo:extMappingInfos) {
        mappingHandlerMapping.unregisterMapping(requestMappingInfo);
      }
    }

    /**
     * 获取刷新前的RequestMappingInfo
     */
    Map<RequestMappingInfo, HandlerMethod> preMappingInfoHandlerMethodMap = mappingHandlerMapping.getHandlerMethods();
    /**
     * 这里注意一定要拿到拷贝，不然刷新后内容就一致了，就没有差量了
     */
    Set<RequestMappingInfo> preRequestMappingInfoSet = new HashSet(preMappingInfoHandlerMethodMap.keySet());

    /**
     * 这里是刷新springmvc上下文
     */
    applicationContext.getBeanFactory().getBeansOfType(RequestMappingHandlerMapping.class)
    .forEach((key,value) ->{
      value.afterPropertiesSet();
    });

    /**
     * 获取刷新后的RequestMappingInfo
     */
    Map<RequestMappingInfo, HandlerMethod> afterMappingInfoHandlerMethodMap = mappingHandlerMapping.getHandlerMethods();
    Set<RequestMappingInfo> afterRequestMappingInfoSet = afterMappingInfoHandlerMethodMap.keySet();

    /**
     * 填充差量部分RequestMappingInfo
     */
    fillSurplusRequestMappingInfos(preRequestMappingInfoSet,afterRequestMappingInfoSet);

    /**
     * 这里真的是不讲武德了，每次调用value.afterPropertiesSet();如下urlLookup都会产生重复，暂时没找到开放方法去掉重复，这里重复会导致
     * 访问的时候报错Ambiguous handler methods mapped for
     * 目标是去掉RequestMappingHandlerMapping -> RequestMappingInfoHandlerMapping -> AbstractHandlerMethodMapping
     * -> mappingRegistry -> urlLookup重复的RequestMappingInfo,这里的.getClass().getSuperclass().getSuperclass()相信会
     * 很懵逼，如果单独通过getClass().getDeclaredMethod("getMappingRegistry",new Class[]{})是无论如何都拿不到父类的非public非
     * protected方法的，因为这个方法不属于子类，只有父类才可以访问到，只有你拿得到你才有资格不讲武德的使用method.setAccessible(true)强行
     * 访问
     */
    Method method = ReflectUtil.getMethod(mappingHandlerMapping,"getMappingRegistry",new Class[]{});
    method.setAccessible(true);
    Object mappingRegistryObj = method.invoke(mappingHandlerMapping,new Object[]{});
    Field field = mappingRegistryObj.getClass().getDeclaredField("urlLookup");
    field.setAccessible(true);
    MultiValueMap<String, RequestMappingInfo> multiValueMap = (MultiValueMap)field.get(mappingRegistryObj);
    multiValueMap.forEach((key,list) -> {
      clearMultyMapping(list);
    });

  }
 /**
   * 填充差量的RequestMappingInfo，因为已经重写过hashCode和equals方法所以可以直接用对象判断是否存在
   * @param preRequestMappingInfoSet
   * @param afterRequestMappingInfoSet
   */
  private void fillSurplusRequestMappingInfos(Set<RequestMappingInfo> preRequestMappingInfoSet,Set<RequestMappingInfo> afterRequestMappingInfoSet) {
    for(RequestMappingInfo requestMappingInfo:afterRequestMappingInfoSet) {
      if(!preRequestMappingInfoSet.contains(requestMappingInfo)) {
        extMappingInfos.add(requestMappingInfo);
      }
    }
  }

  /**
   * 简单的逻辑，删除List里重复的RequestMappingInfo，已经写了toString，直接使用mappingInfo.toString()就可以区分重复了
   * @param mappingInfos
   */
  private void clearMultyMapping(List<RequestMappingInfo> mappingInfos) {
    Set<String> containsList = new HashSet<>();
    for(Iterator<RequestMappingInfo> iter = mappingInfos.iterator();iter.hasNext();) {
      RequestMappingInfo mappingInfo = iter.next();
      String flag = mappingInfo.toString();
      if(containsList.contains(flag)) {
        iter.remove();
      } else {
        containsList.add(flag);
      }
    }
  }

}

classLoaderDefineClass = (Method) AccessController.doPrivileged(new PrivilegedExceptionAction() {
  public Object run() throws Exception {
   return ClassLoader.class.getDeclaredMethod("defineClass",
      String.class, byte[].class, Integer.TYPE, Integer.TYPE, ProtectionDomain.class);
  }
});
classLoaderDefineClassMethod = classLoaderDefineClass;
// Classic option: protected ClassLoader.defineClass method
if (c == null && classLoaderDefineClassMethod != null) {
  if (protectionDomain == null) {
   protectionDomain = PROTECTION_DOMAIN;
  }
  Object[] args = new Object[]{className, b, 0, b.length, protectionDomain};
  try {
   if (!classLoaderDefineClassMethod.isAccessible()) {
     classLoaderDefineClassMethod.setAccessible(true);
   }
   c = (Class) classLoaderDefineClassMethod.invoke(loader, args);
  }
  catch (InvocationTargetException ex) {
   throw new CodeGenerationException(ex.getTargetException());
  }
  catch (Throwable ex) {
   // Fall through if setAccessible fails with InaccessibleObjectException on JDK 9+
   // (on the module path and/or with a JVM bootstrapped with --illegal-access=deny)
   if (!ex.getClass().getName().endsWith("InaccessibleObjectException")) {
     throw new CodeGenerationException(ex);
   }
  }
}

/**
     * 这里真的是不讲武德了，每次调用value.afterPropertiesSet();如下urlLookup都会产生重复，暂时没找到开放方法去掉重复，这里重复会导致
     * 访问的时候报错Ambiguous handler methods mapped for
     * 目标是去掉RequestMappingHandlerMapping -> RequestMappingInfoHandlerMapping -> AbstractHandlerMethodMapping
     * -> mappingRegistry -> urlLookup重复的RequestMappingInfo,这里的.getClass().getSuperclass().getSuperclass()相信会
     * 很懵逼，如果单独通过getClass().getDeclaredMethod("getMappingRegistry",new Class[]{})是无论如何都拿不到父类的非public非
     * protected方法的，因为这个方法不属于子类，只有父类才可以访问到，只有你拿得到你才有资格不讲武德的使用method.setAccessible(true)强行
     * 访问
     */
    Method method = ReflectUtil.getMethod(mappingHandlerMapping,"getMappingRegistry",new Class[]{});
    method.setAccessible(true);
    Object mappingRegistryObj = method.invoke(mappingHandlerMapping,new Object[]{});
    Field field = mappingRegistryObj.getClass().getDeclaredField("urlLookup");
    field.setAccessible(true);
    MultiValueMap<String, RequestMappingInfo> multiValueMap = (MultiValueMap)field.get(mappingRegistryObj);
    multiValueMap.forEach((key,list) -> {
      clearMultyMapping(list);
    });

 　　/**
   * 简单的逻辑，删除List里重复的RequestMappingInfo，已经写了toString，直接使用mappingInfo.toString()就可以区分重复了
   * @param mappingInfos
   */
  private void clearMultyMapping(List<RequestMappingInfo> mappingInfos) {
    Set<String> containsList = new HashSet<>();
    for(Iterator<RequestMappingInfo> iter = mappingInfos.iterator();iter.hasNext();) {
      RequestMappingInfo mappingInfo = iter.next();
      String flag = mappingInfo.toString();
      if(containsList.contains(flag)) {
        iter.remove();
      } else {
        containsList.add(flag);
      }
    }
  }

@Configuration
@EnableSwagger2
public class SwaggerConfig {

  //swagger2的配置文件，这里可以配置swagger2的一些基本的内容，比如扫描的包等等
  @Bean
  public Docket createRestApi() {
    List<ResponseMessage> responseMessageList = new ArrayList<>();
    responseMessageList.add(new ResponseMessageBuilder().code(200).message("成功").responseModel(new ModelRef("Payload")).build());
    Docket docket = new Docket(DocumentationType.SWAGGER_2)
        .globalResponseMessage(RequestMethod.GET,responseMessageList)
        .globalResponseMessage(RequestMethod.DELETE,responseMessageList)
        .globalResponseMessage(RequestMethod.POST,responseMessageList)
        .apiInfo(apiInfo()).select()
        //为当前包路径
        .apis(RequestHandlerSelectors.basePackage("com.xxx")).paths(PathSelectors.any()).build();
    return docket;
  }

  //构建 api文档的详细信息函数,注意这里的注解引用的是哪个
  private ApiInfo apiInfo() {
    return new ApiInfoBuilder()
        //页面标题
        .title("使用 Swagger2 构建RESTful API")
        //创建人
        .contact(new Contact("rongdi", "https://www.cnblogs.com/rongdi", "495194630@qq.com"))
        //版本号
        .version("1.0")
        //描述
        .description("api管理").build();
  }

}

//swagger2的配置文件，这里可以配置swagger2的一些基本的内容，比如扫描的包等等
  @Bean
  public Docket createRestApi() {
    List<ResponseMessage> responseMessageList = new ArrayList<>();
    responseMessageList.add(new ResponseMessageBuilder().code(200).message("成功").responseModel(new ModelRef("Payload")).build());
    Docket docket = new Docket(DocumentationType.SWAGGER_2)
        .globalResponseMessage(RequestMethod.GET,responseMessageList)
        .globalResponseMessage(RequestMethod.DELETE,responseMessageList)
        .globalResponseMessage(RequestMethod.POST,responseMessageList)
        .apiInfo(apiInfo()).select()
        //为当前包路径
        .apis(RequestHandlerSelectors.basePackage("com.xxx")).paths(PathSelectors.any()).build();
    return docket;
  }

/**
   * 刷新springMVC,这里花了大量时间调试，找不到开放的方法，只能取个巧，在更新RequestMappingHandlerMapping前先记录之前
   * 所有RequestMappingInfo，记得这里一定要copy一下，然后刷新后再记录一次，计算出差量存放在成员变量Set中，然后每次开头判断
   * 差量那里是否有内容，有就先unregiester掉
   */
  private void refreshMVC(ConfigurableApplicationContext applicationContext) throws Exception {


    Map<String, RequestMappingHandlerMapping> map = applicationContext.getBeanFactory().getBeansOfType(RequestMappingHandlerMapping.class);
    /**
     * 先拿到RequestMappingHandlerMapping对象
     */
    RequestMappingHandlerMapping mappingHandlerMapping = map.get("requestMappingHandlerMapping");

    /**
     * 重新注册mapping前先判断是否存在了，存在了就先unregister掉
     */
    if(!extMappingInfos.isEmpty()) {
      for(RequestMappingInfo requestMappingInfo:extMappingInfos) {
        mappingHandlerMapping.unregisterMapping(requestMappingInfo);
      }
    }

    /**
     * 获取刷新前的RequestMappingInfo
     */
    Map<RequestMappingInfo, HandlerMethod> preMappingInfoHandlerMethodMap = mappingHandlerMapping.getHandlerMethods();
    /**
     * 这里注意一定要拿到拷贝，不然刷新后内容就一致了，就没有差量了
     */
    Set<RequestMappingInfo> preRequestMappingInfoSet = new HashSet(preMappingInfoHandlerMethodMap.keySet());

    /**
     * 这里是刷新springmvc上下文
     */
    applicationContext.getBeanFactory().getBeansOfType(RequestMappingHandlerMapping.class)
    .forEach((key,value) ->{
      value.afterPropertiesSet();
    });

    /**
     * 获取刷新后的RequestMappingInfo
     */
    Map<RequestMappingInfo, HandlerMethod> afterMappingInfoHandlerMethodMap = mappingHandlerMapping.getHandlerMethods();
    Set<RequestMappingInfo> afterRequestMappingInfoSet = afterMappingInfoHandlerMethodMap.keySet();

    /**
     * 填充差量部分RequestMappingInfo
     */
    fillSurplusRequestMappingInfos(preRequestMappingInfoSet,afterRequestMappingInfoSet);

    /**
     * 这里真的是不讲武德了，每次调用value.afterPropertiesSet();如下urlLookup都会产生重复，暂时没找到开放方法去掉重复，这里重复会导致
     * 访问的时候报错Ambiguous handler methods mapped for
     * 目标是去掉RequestMappingHandlerMapping -> RequestMappingInfoHandlerMapping -> AbstractHandlerMethodMapping
     * -> mappingRegistry -> urlLookup重复的RequestMappingInfo,这里的.getClass().getSuperclass().getSuperclass()相信会
     * 很懵逼，如果单独通过getClass().getDeclaredMethod("getMappingRegistry",new Class[]{})是无论如何都拿不到父类的非public非
     * protected方法的，因为这个方法不属于子类，只有父类才可以访问到，只有你拿得到你才有资格不讲武德的使用method.setAccessible(true)强行
     * 访问
     */
    Method method = ReflectUtil.getMethod(mappingHandlerMapping,"getMappingRegistry",new Class[]{});
    method.setAccessible(true);
    Object mappingRegistryObj = method.invoke(mappingHandlerMapping,new Object[]{});
    Field field = mappingRegistryObj.getClass().getDeclaredField("urlLookup");
    field.setAccessible(true);
    MultiValueMap<String, RequestMappingInfo> multiValueMap = (MultiValueMap)field.get(mappingRegistryObj);
    multiValueMap.forEach((key,list) -> {
      clearMultyMapping(list);
    });

    /**
     * 刷新swagger文档
     */
    refreshSwagger(applicationContext);
  }


  /**
   * 刷新swagger文档
   * @param applicationContext
   * @throws Exception
   */
  private void refreshSwagger(ConfigurableApplicationContext applicationContext) throws Exception {
    /**
     * 获取扩展包swagger的地址接口扫描包，如果有配置则执行文档刷新操作
     */
    String extSwaggerDocPackage = applicationContext.getEnvironment().getProperty(DYNAMIC_DOC_PACKAGE);
    if (!StringUtils.isEmpty(extSwaggerDocPackage)) {
      /**
       * 拿到swagger解析文档的入口类，真的不想这样，主要是根本不提供刷新和重新加载文档的方法，只能不讲武德了
       */
      DocumentationPluginsBootstrapper bootstrapper = applicationContext.getBeanFactory().getBean(DocumentationPluginsBootstrapper.class);
      /**
       * 不管愿不愿意，强行拿到属性得到documentationPluginsManager对象
       */
      Field field1 = bootstrapper.getClass().getDeclaredField("documentationPluginsManager");
      field1.setAccessible(true);
      DocumentationPluginsManager documentationPluginsManager = (DocumentationPluginsManager) field1.get(bootstrapper);

      /**
       * 继续往下层拿documentationPlugins属性
       */
      Field field2 = documentationPluginsManager.getClass().getDeclaredField("documentationPlugins");
      field2.setAccessible(true);
      PluginRegistry<DocumentationPlugin, DocumentationType> pluginRegistrys = (PluginRegistry<DocumentationPlugin, DocumentationType>) field2.get(documentationPluginsManager);
      /**
       * 拿到最关键的文档插件集合，所有逻辑文档解析逻辑都在插件中
       */
      List<DocumentationPlugin> dockets = pluginRegistrys.getPlugins();
      /**
       * 真的不能怪我，好端端，你还搞个不能修改的集合，强行往父类递归拿到unmodifiableList的list属性
       */
      Field unModList = ReflectUtil.getField(dockets,"list");
      unModList.setAccessible(true);
      List<DocumentationPlugin> modifyerList = (List<DocumentationPlugin>) unModList.get(dockets);
      /**
       * 这下老实了吧，把自己的Docket加入进去，这里的groupName为dynamic
       */
      modifyerList.add(createRestApi(extSwaggerDocPackage));
      /**
       * 清空罪魁祸首DocumentationCache缓存，不然就算再加载一次，获取文档还是从这个缓存中拿，不会完成更新
       */
      bootstrapper.stop();
      /**
       * 手动执行重新解析swagger文档
       */
      bootstrapper.start();
    }
  }

  public Docket createRestApi(String basePackage) {
    List<ResponseMessage> responseMessageList = new ArrayList<>();
    responseMessageList.add(new ResponseMessageBuilder().code(200).message("成功").responseModel(new ModelRef("Payload")).build());
    Docket docket = new Docket(DocumentationType.SWAGGER_2)
        .groupName("dynamic")
        .globalResponseMessage(RequestMethod.GET,responseMessageList)
        .globalResponseMessage(RequestMethod.DELETE,responseMessageList)
        .globalResponseMessage(RequestMethod.POST,responseMessageList)
        .apiInfo(apiInfo()).select()
        //为当前包路径
        .apis(RequestHandlerSelectors.basePackage(basePackage)).paths(PathSelectors.any()).build();
    return docket;
  }

  /**
   * 构建api文档的详细信息函数
   */
  private ApiInfo apiInfo() {
    return new ApiInfoBuilder()
        //页面标题
        .title("SpringBoot动态扩展")
        //创建人
        .contact(new Contact("rongdi", "https://www.cnblogs.com/rongdi", "495194630@qq.com"))
        //版本号
        .version("1.0")
        //描述
        .description("api管理").build();
  }

package com.rdpaas.dynamic.config;

import com.rdpaas.dynamic.core.ModuleApplication;
import org.apache.ibatis.session.SqlSessionFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.context.event.ApplicationStartedEvent;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.ApplicationListener;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.net.URL;

/**
 * 一切配置的入口
 * @author rongdi
 * @date 2021-03-06
 * @blog https://www.cnblogs.com/rongdi
 */
@Configuration
public class DynamicConfig implements ApplicationContextAware {

  private static final Logger logger = LoggerFactory.getLogger(DynamicConfig.class);

  @Autowired
  private SqlSessionFactory sqlSessionFactory;

  private ApplicationContext applicationContext;

  @Value("${dynamic.jar:/}")
  private String dynamicJar;

  @Bean
  public ModuleApplication moduleApplication() throws Exception {
    return new ModuleApplication();
  }

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

  /**
   * 随便找个事件ApplicationStartedEvent，用来reload外部的jar，其实直接在moduleApplication()方法也可以做
   * 这件事，但是为了验证容器初始化后再加载扩展包还可以生效，所以故意放在了这里。
   * @return
   */
  @Bean
  @ConditionalOnProperty(prefix = "dynamic",name = "jar")
  public ApplicationListener applicationListener1() {
    return (ApplicationListener<ApplicationStartedEvent>) event -> {
      try {
        /**
         * 加载外部扩展jar
         */
        moduleApplication().reloadJar(new URL(dynamicJar),applicationContext,sqlSessionFactory);
      } catch (Exception e) {
        logger.error("",e);
      }

    };
  }


}

package com.rdpaas.dynamic.anno;

import com.rdpaas.dynamic.config.DynamicConfig;
import org.springframework.context.annotation.Import;

import java.lang.annotation.*;

/**
 * 开启动态扩展的注解
 * @author rongdi
 * @date 2021-03-06
 * @blog https://www.cnblogs.com/rongdi
 */
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE})
@Documented
@Import({DynamicConfig.class})
public @interface EnableDynamic {
}