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Divide插件源码分析

· One min read
midnight2104
Apache ShenYu Committer

Apache ShenYu 是一个异步的，高性能的，跨语言的，响应式的 API 网关。

ShenYu 网关使用 divide 插件来处理 http 请求。你可以查看官方文档 Http快速开始 了解如何使用该插件。

本文基于shenyu-2.4.3版本进行源码分析，官网的介绍请参考 Http服务接入 。

1. 服务注册#

1.1 声明注册接口#

使用注解@ShenyuSpringMvcClient将服务注册到网关。简单demo如下：

@RestController@RequestMapping("/order")@ShenyuSpringMvcClient(path = "/order")  // API注册public class OrderController {    @GetMapping("/findById")    @ShenyuSpringMvcClient(path = "/findById", desc = "Find by id") // 方法注册    public OrderDTO findById(@RequestParam("id") final String id) {        return build(id, "hello world findById");    }}

注解定义：


/** * 作用于类和方法上 */@Retention(RetentionPolicy.RUNTIME)@Target({ElementType.TYPE, ElementType.METHOD})public @interface ShenyuSpringMvcClient {        //注册路径    String path() default "";        //规则名称    String ruleName() default "";       //描述信息    String desc() default "";
    //是否启用    boolean enabled() default true;        //注册元数据    boolean registerMetaData() default false;}

1.2 扫描注解信息#

注解扫描通过SpringMvcClientBeanPostProcessor完成，它实现了BeanPostProcessor接口，是Spring提供的后置处理器。

在构造器实例化的过程中：

  • 读取属性配置
  • 添加注解，读取path信息
  • 启动注册中心，向shenyu-admin注册
public class SpringMvcClientBeanPostProcessor implements BeanPostProcessor {    //...    /**     * 构造器实例化     */    public SpringMvcClientBeanPostProcessor(final PropertiesConfig clientConfig,                                            final ShenyuClientRegisterRepository shenyuClientRegisterRepository) {        // 1. 读取属性配置        Properties props = clientConfig.getProps();        this.appName = props.getProperty(ShenyuClientConstants.APP_NAME);        this.contextPath = props.getProperty(ShenyuClientConstants.CONTEXT_PATH, "");        if (StringUtils.isBlank(appName) && StringUtils.isBlank(contextPath)) {            String errorMsg = "http register param must config the appName or contextPath";            LOG.error(errorMsg);            throw new ShenyuClientIllegalArgumentException(errorMsg);        }        this.isFull = Boolean.parseBoolean(props.getProperty(ShenyuClientConstants.IS_FULL, Boolean.FALSE.toString()));        // 2. 添加注解        mappingAnnotation.add(ShenyuSpringMvcClient.class);        mappingAnnotation.add(PostMapping.class);        mappingAnnotation.add(GetMapping.class);        mappingAnnotation.add(DeleteMapping.class);        mappingAnnotation.add(PutMapping.class);        mappingAnnotation.add(RequestMapping.class);        // 3. 启动注册中心        publisher.start(shenyuClientRegisterRepository);    }        @Override    public Object postProcessAfterInitialization(@NonNull final Object bean, @NonNull final String beanName) throws BeansException {       // 重写后置处理器逻辑                return bean;    }
  • SpringMvcClientBeanPostProcessor#postProcessAfterInitialization()

重写后置处理器逻辑：读取注解信息，构建元数据对象和URI对象，并向shenyu-admin注册。

    @Override    public Object postProcessAfterInitialization(@NonNull final Object bean, @NonNull final String beanName) throws BeansException {        // 1. 如果是注册整个服务或者不是Controller类，就不处理        if (Boolean.TRUE.equals(isFull) || !hasAnnotation(bean.getClass(), Controller.class)) {            return bean;        }        // 2. 读取类上的注解 ShenyuSpringMvcClient        final ShenyuSpringMvcClient beanShenyuClient = AnnotationUtils.findAnnotation(bean.getClass(), ShenyuSpringMvcClient.class);        // 2.1构建superPath        final String superPath = buildApiSuperPath(bean.getClass());        // 2.2 是否注册整个类方法        if (Objects.nonNull(beanShenyuClient) && superPath.contains("*")) {            // 构建元数据对象，然后向shenyu-admin注册            publisher.publishEvent(buildMetaDataDTO(beanShenyuClient, pathJoin(contextPath, superPath)));            return bean;        }        // 3. 读取所有方法        final Method[] methods = ReflectionUtils.getUniqueDeclaredMethods(bean.getClass());        for (Method method : methods) {            // 3.1 读取方法上的注解 ShenyuSpringMvcClient            ShenyuSpringMvcClient methodShenyuClient = AnnotationUtils.findAnnotation(method, ShenyuSpringMvcClient.class);            // 如果方法上面没有注解，就用类上面的注解            methodShenyuClient = Objects.isNull(methodShenyuClient) ? beanShenyuClient : methodShenyuClient;            if (Objects.nonNull(methodShenyuClient)) {               // 3.2 构建path信息，构建元数据对象，向shenyu-admin注册                publisher.publishEvent(buildMetaDataDTO(methodShenyuClient, buildApiPath(method, superPath)));            }        }                return bean;    }
  • 1.如果是注册整个服务或者不是Controller类，就不处理
  • 2.读取类上的注解 ShenyuSpringMvcClient，如果是注册整个类，就在这里构建元数据对象，然后向shenyu-admin注册
  • 3.处理方法上的注解 ShenyuSpringMvcClient，针对特定方法构建path信息，构建元数据对象，然后向shenyu-admin注册

这里有两个取path的方法，需要特别说明一下：

  • buildApiSuperPath()

    构造SuperPath：先从类上的注解ShenyuSpringMvcClient取path属性，如果没有，就从当前类的RequestMapping注解中取path信息。

    private String buildApiSuperPath(@NonNull final Class<?> method) {        // 先从类上的注解ShenyuSpringMvcClient取path属性        ShenyuSpringMvcClient shenyuSpringMvcClient = AnnotationUtils.findAnnotation(method, ShenyuSpringMvcClient.class);        if (Objects.nonNull(shenyuSpringMvcClient) && StringUtils.isNotBlank(shenyuSpringMvcClient.path())) {            return shenyuSpringMvcClient.path();        }        // 从当前类的RequestMapping注解中取path信息        RequestMapping requestMapping = AnnotationUtils.findAnnotation(method, RequestMapping.class);        if (Objects.nonNull(requestMapping) && ArrayUtils.isNotEmpty(requestMapping.path()) && StringUtils.isNotBlank(requestMapping.path()[0])) {            return requestMapping.path()[0];        }        return "";    }

  • buildApiPath()

    构建path：先读取方法上的注解ShenyuSpringMvcClient，如果存在就构建；否则从方法的其他注解上获取path信息；完整的path = contextPath(上下文信息)+superPath(类信息)+methodPath(方法信息)。

    private String buildApiPath(@NonNull final Method method, @NonNull final String superPath) {        // 1. 读取方法上的注解ShenyuSpringMvcClient        ShenyuSpringMvcClient shenyuSpringMvcClient = AnnotationUtils.findAnnotation(method, ShenyuSpringMvcClient.class);        // 1.1如果存在path，就构建        if (Objects.nonNull(shenyuSpringMvcClient) && StringUtils.isNotBlank(shenyuSpringMvcClient.path())) {            //1.2完整 path = contextPath+superPath+methodPath            return pathJoin(contextPath, superPath, shenyuSpringMvcClient.path());        }        // 2.从方法的其他注解上获取path信息        final String path = getPathByMethod(method);        if (StringUtils.isNotBlank(path)) {             // 2.1 完整的path = contextPath+superPath+methodPath            return pathJoin(contextPath, superPath, path);        }        return pathJoin(contextPath, superPath);    }

  • getPathByMethod()

    从方法的其他注解上获取path信息，其他注解包括：

    • ShenyuSpringMvcClient
    • PostMapping
    • GetMapping
    • DeleteMapping
    • PutMapping
    • RequestMapping

    private String getPathByMethod(@NonNull final Method method) {        // 遍历接口注解获取path信息        for (Class<? extends Annotation> mapping : mappingAnnotation) {            final String pathByAnnotation = getPathByAnnotation(AnnotationUtils.findAnnotation(method, mapping), pathAttributeNames);            if (StringUtils.isNotBlank(pathByAnnotation)) {                return pathByAnnotation;            }        }        return null;    }

扫描注解完成后，构建元数据对象，然后将该对象发送到shenyu-admin，即可完成注册。

  • 元数据对象

    包括当前注册方法的规则信息：contextPath，appName，注册路径，描述信息，注册类型，是否启用，规则名称和是否注册元数据。

 private MetaDataRegisterDTO buildMetaDataDTO(@NonNull final ShenyuSpringMvcClient shenyuSpringMvcClient, final String path) {        return MetaDataRegisterDTO.builder()                .contextPath(contextPath) // contextPath                .appName(appName) // appName                .path(path) // 注册路径，在网关规则匹配时使用                .pathDesc(shenyuSpringMvcClient.desc()) // 描述信息                .rpcType(RpcTypeEnum.HTTP.getName()) // divide插件，默认时http类型                .enabled(shenyuSpringMvcClient.enabled()) // 是否启用规则                .ruleName(StringUtils.defaultIfBlank(shenyuSpringMvcClient.ruleName(), path))//规则名称                .registerMetaData(shenyuSpringMvcClient.registerMetaData()) //是否注册元数据信息                .build();    }

具体的注册逻辑由注册中心实现，在之前的文章中已经分析过了，这里就不再深入分析。

1.3 注册URI信息#

ContextRegisterListener负责将客户端的URI信息注册到shenyu-admin，它实现了ApplicationListener接口，发生上下文刷新事件ContextRefreshedEvent时，执行onApplicationEvent()方法，实现注册逻辑。


public class ContextRegisterListener implements ApplicationListener<ContextRefreshedEvent>, BeanFactoryAware {    //......        /**     * 构造器实例化     */    public ContextRegisterListener(final PropertiesConfig clientConfig) {        // 读取属性配置        final Properties props = clientConfig.getProps();        this.isFull = Boolean.parseBoolean(props.getProperty(ShenyuClientConstants.IS_FULL, Boolean.FALSE.toString()));        this.contextPath = props.getProperty(ShenyuClientConstants.CONTEXT_PATH);        if (Boolean.TRUE.equals(isFull)) {            if (StringUtils.isBlank(contextPath)) {                final String errorMsg = "http register param must config the contextPath";                LOG.error(errorMsg);                throw new ShenyuClientIllegalArgumentException(errorMsg);            }        }        this.port = Integer.parseInt(Optional.ofNullable(props.getProperty(ShenyuClientConstants.PORT)).orElseGet(() -> "-1"));        this.appName = props.getProperty(ShenyuClientConstants.APP_NAME);        this.protocol = props.getProperty(ShenyuClientConstants.PROTOCOL, ShenyuClientConstants.HTTP);        this.host = props.getProperty(ShenyuClientConstants.HOST);    }
    @Override    public void setBeanFactory(final BeanFactory beanFactory) throws BeansException {        this.beanFactory = beanFactory;    }
    // 执行应用事件    @Override    public void onApplicationEvent(@NonNull final ContextRefreshedEvent contextRefreshedEvent) {        // 保证该方法执行一次        if (!registered.compareAndSet(false, true)) {            return;        }        // 1. 如果是注册整个服务        if (Boolean.TRUE.equals(isFull)) {            // 构建元数据，并注册            publisher.publishEvent(buildMetaDataDTO());        }        try {            // 获取端口信息            final int mergedPort = port <= 0 ? PortUtils.findPort(beanFactory) : port;            // 2. 构建URI数据，并注册            publisher.publishEvent(buildURIRegisterDTO(mergedPort));        } catch (ShenyuException e) {            throw new ShenyuException(e.getMessage() + "please config ${shenyu.client.http.props.port} in xml/yml !");        }    }
    // 构建URI数据    private URIRegisterDTO buildURIRegisterDTO(final int port) {        return URIRegisterDTO.builder()            .contextPath(this.contextPath) // contextPath            .appName(appName) // appName            .protocol(protocol) // 服务使用的协议            .host(IpUtils.isCompleteHost(this.host) ? this.host : IpUtils.getHost(this.host)) //主机            .port(port) // 端口            .rpcType(RpcTypeEnum.HTTP.getName()) // divide插件，默认注册http类型            .build();    }
    // 构建元数据    private MetaDataRegisterDTO buildMetaDataDTO() {        return MetaDataRegisterDTO.builder()            .contextPath(contextPath)            .appName(appName)            .path(contextPath)            .rpcType(RpcTypeEnum.HTTP.getName())            .enabled(true)            .ruleName(contextPath)            .build();    }}

1.4 处理注册信息#

客户端通过注册中心注册的元数据和URI数据，在shenyu-admin进行处理，负责存储到数据库和同步给shenyu网关。Divide插件的客户端注册处理逻辑在ShenyuClientRegisterDivideServiceImpl中。继承关系如下：

  • ShenyuClientRegisterService：客户端注册服务，顶层接口；
  • FallbackShenyuClientRegisterService：注册失败，提供重试操作；
  • AbstractShenyuClientRegisterServiceImpl：抽象类，实现部分公共注册逻辑；
  • AbstractContextPathRegisterService：抽象类，负责注册ContextPath；
  • ShenyuClientRegisterDivideServiceImpl：实现Divide插件的注册；
1.4.1 注册服务#

  • org.apache.shenyu.admin.service.register.AbstractShenyuClientRegisterServiceImpl#register()

    客户端通过注册中心注册的元数据MetaDataRegisterDTO对象在shenyu-admin的register()方法被接送到。

   @Override    public String register(final MetaDataRegisterDTO dto) {        //1. 注册选择器        String selectorHandler = selectorHandler(dto);        String selectorId = selectorService.registerDefault(dto, PluginNameAdapter.rpcTypeAdapter(rpcType()), selectorHandler);        //2. 注册规则        String ruleHandler = ruleHandler();        RuleDTO ruleDTO = buildRpcDefaultRuleDTO(selectorId, dto, ruleHandler);        ruleService.registerDefault(ruleDTO);        //3. 注册元数据        registerMetadata(dto);        //4. 注册ContextPath        String contextPath = dto.getContextPath();        if (StringUtils.isNotEmpty(contextPath)) {            registerContextPath(dto);        }        return ShenyuResultMessage.SUCCESS;    }
1.4.1.1 注册选择器#
  • org.apache.shenyu.admin.service.impl.SelectorServiceImpl#registerDefault()

构建contextPath，查找选择器信息是否存在，如果存在就返回id；不存在就创建默认的选择器信息。

    @Override    public String registerDefault(final MetaDataRegisterDTO dto, final String pluginName, final String selectorHandler) {        // 构建contextPath        String contextPath = ContextPathUtils.buildContextPath(dto.getContextPath(), dto.getAppName());        // 通过名称查找选择器信息是否存在        SelectorDO selectorDO = findByNameAndPluginName(contextPath, pluginName);        if (Objects.isNull(selectorDO)) {            // 不存在就创建默认的选择器信息            return registerSelector(contextPath, pluginName, selectorHandler);        }        return selectorDO.getId();    }

  • 默认选择器信息

    在这里构建默认选择器信息及其条件属性。

   //注册选择器   private String registerSelector(final String contextPath, final String pluginName, final String selectorHandler) {        //构建选择器        SelectorDTO selectorDTO = buildSelectorDTO(contextPath, pluginMapper.selectByName(pluginName).getId());        selectorDTO.setHandle(selectorHandler);        //注册默认选择器        return registerDefault(selectorDTO);    }     //构建选择器    private SelectorDTO buildSelectorDTO(final String contextPath, final String pluginId) {        //构建默认选择器        SelectorDTO selectorDTO = buildDefaultSelectorDTO(contextPath);        selectorDTO.setPluginId(pluginId);         //构建默认选择器的条件属性        selectorDTO.setSelectorConditions(buildDefaultSelectorConditionDTO(contextPath));        return selectorDTO;    }
  • 构建默认选择器
private SelectorDTO buildDefaultSelectorDTO(final String name) {    return SelectorDTO.builder()            .name(name) // 名称            .type(SelectorTypeEnum.CUSTOM_FLOW.getCode()) // 默认类型自定义            .matchMode(MatchModeEnum.AND.getCode()) //默认匹配方式 and            .enabled(Boolean.TRUE)  //默认启开启            .loged(Boolean.TRUE)  //默认记录日志            .continued(Boolean.TRUE) //默认继续后续选择器            .sort(1) //默认顺序1            .build();}
  • 构建默认选择器条件属性
private List<SelectorConditionDTO> buildDefaultSelectorConditionDTO(final String contextPath) {    SelectorConditionDTO selectorConditionDTO = new SelectorConditionDTO();    selectorConditionDTO.setParamType(ParamTypeEnum.URI.getName()); // 默认参数类型URI    selectorConditionDTO.setParamName("/");    selectorConditionDTO.setOperator(OperatorEnum.MATCH.getAlias()); // 默认匹配策略 match    selectorConditionDTO.setParamValue(contextPath + AdminConstants.URI_SUFFIX); // 默认值 /contextPath/**    return Collections.singletonList(selectorConditionDTO);}
  • 注册默认选择器
@Overridepublic String registerDefault(final SelectorDTO selectorDTO) {    //选择器信息    SelectorDO selectorDO = SelectorDO.buildSelectorDO(selectorDTO);    //选择器条件属性    List<SelectorConditionDTO> selectorConditionDTOs = selectorDTO.getSelectorConditions();    if (StringUtils.isEmpty(selectorDTO.getId())) {        // 向数据库插入选择器信息        selectorMapper.insertSelective(selectorDO);          // 向数据库插入选择器条件属性        selectorConditionDTOs.forEach(selectorConditionDTO -> {            selectorConditionDTO.setSelectorId(selectorDO.getId());                        selectorConditionMapper.insertSelective(SelectorConditionDO.buildSelectorConditionDO(selectorConditionDTO));        });    }    // 发布同步事件，向网关同步选择信息及其条件属性    publishEvent(selectorDO, selectorConditionDTOs);    return selectorDO.getId();}
1.4.1.2 注册规则#

在注册服务的第二步中，开始构建默认规则，然后注册规则。

@Override    public String register(final MetaDataRegisterDTO dto) {        //1. 注册选择器        //......                //2. 注册规则        // 默认规则处理属性        String ruleHandler = ruleHandler();        // 构建默认规则信息        RuleDTO ruleDTO = buildRpcDefaultRuleDTO(selectorId, dto, ruleHandler);        // 注册规则        ruleService.registerDefault(ruleDTO);                //3. 注册元数据        //......                //4. 注册ContextPath        //......                return ShenyuResultMessage.SUCCESS;    }
  • 默认规则处理属性
    @Override    protected String ruleHandler() {        // 默认规则处理属性        return new DivideRuleHandle().toJson();    }

Divide插件默认规则处理属性


public class DivideRuleHandle implements RuleHandle {
    /**     * 负载均衡：默认随机     */    private String loadBalance = LoadBalanceEnum.RANDOM.getName();
    /**     * 重试策略：默认重试当前服务     */    private String retryStrategy = RetryEnum.CURRENT.getName();
    /**     * 重试次数：默认3次     */    private int retry = 3;
    /**     * 调用超时：默认 3000     */    private long timeout = Constants.TIME_OUT;
    /**     * header最大值：10240 byte     */    private long headerMaxSize = Constants.HEADER_MAX_SIZE;
    /**     * request最大值：102400 byte     */    private long requestMaxSize = Constants.REQUEST_MAX_SIZE;}
  • 构建默认规则信息
  // 构建默认规则信息    private RuleDTO buildRpcDefaultRuleDTO(final String selectorId, final MetaDataRegisterDTO metaDataDTO, final String ruleHandler) {        return buildRuleDTO(selectorId, ruleHandler, metaDataDTO.getRuleName(), metaDataDTO.getPath());    }   //  构建默认规则信息    private RuleDTO buildRuleDTO(final String selectorId, final String ruleHandler, final String ruleName, final String path) {        RuleDTO ruleDTO = RuleDTO.builder()                .selectorId(selectorId) //关联的选择器id                .name(ruleName) //规则名称                .matchMode(MatchModeEnum.AND.getCode()) // 默认匹配模式 and                .enabled(Boolean.TRUE) // 默认开启                .loged(Boolean.TRUE) //默认记录日志                .sort(1) //默认顺序 1                .handle(ruleHandler)                .build();        RuleConditionDTO ruleConditionDTO = RuleConditionDTO.builder()                .paramType(ParamTypeEnum.URI.getName()) // 默认参数类型URI                .paramName("/")                .paramValue(path) //参数值path                .build();        if (path.indexOf("*") > 1) {            ruleConditionDTO.setOperator(OperatorEnum.MATCH.getAlias()); //如果path中有*，操作类型则默认为 match        } else {            ruleConditionDTO.setOperator(OperatorEnum.EQ.getAlias()); // 否则，默认操作类型 =         }        ruleDTO.setRuleConditions(Collections.singletonList(ruleConditionDTO));        return ruleDTO;    }
  • org.apache.shenyu.admin.service.impl.RuleServiceImpl#registerDefault()

注册规则：向数据库插入记录，并向网关发布事件，进行数据同步。


    @Override    public String registerDefault(final RuleDTO ruleDTO) {        RuleDO exist = ruleMapper.findBySelectorIdAndName(ruleDTO.getSelectorId(), ruleDTO.getName());        if (Objects.nonNull(exist)) {            return "";        }
        RuleDO ruleDO = RuleDO.buildRuleDO(ruleDTO);        List<RuleConditionDTO> ruleConditions = ruleDTO.getRuleConditions();        if (StringUtils.isEmpty(ruleDTO.getId())) {            // 向数据库插入规则信息            ruleMapper.insertSelective(ruleDO);            //向数据库插入规则体条件属性            ruleConditions.forEach(ruleConditionDTO -> {                ruleConditionDTO.setRuleId(ruleDO.getId());                            ruleConditionMapper.insertSelective(RuleConditionDO.buildRuleConditionDO(ruleConditionDTO));            });        }        // 向网关发布事件，进行数据同步        publishEvent(ruleDO, ruleConditions);        return ruleDO.getId();    }
1.4.1.3 注册元数据#
   @Override    public String register(final MetaDataRegisterDTO dto) {        //1. 注册选择器        //......                //2. 注册规则        //......                //3. 注册元数据        registerMetadata(dto);                //4. 注册ContextPath        //......                return ShenyuResultMessage.SUCCESS;    }

  • org.apache.shenyu.admin.service.register.ShenyuClientRegisterDivideServiceImpl#registerMetadata()

    插入或更新元数据，然后发布同步事件到网关。


    @Override    protected void registerMetadata(final MetaDataRegisterDTO dto) {        if (dto.isRegisterMetaData()) { // 如果注册元数据            // 获取metaDataService            MetaDataService metaDataService = getMetaDataService();            // 元数据是否存在            MetaDataDO exist = metaDataService.findByPath(dto.getPath());            // 插入或更新元数据            metaDataService.saveOrUpdateMetaData(exist, dto);        }    }
    @Override    public void saveOrUpdateMetaData(final MetaDataDO exist, final MetaDataRegisterDTO metaDataDTO) {        DataEventTypeEnum eventType;        // 数据类型转换 DTO->DO        MetaDataDO metaDataDO = MetaDataTransfer.INSTANCE.mapRegisterDTOToEntity(metaDataDTO);        // 插入数据        if (Objects.isNull(exist)) {            Timestamp currentTime = new Timestamp(System.currentTimeMillis());            metaDataDO.setId(UUIDUtils.getInstance().generateShortUuid());            metaDataDO.setDateCreated(currentTime);            metaDataDO.setDateUpdated(currentTime);            metaDataMapper.insert(metaDataDO);            eventType = DataEventTypeEnum.CREATE;        } else {            // 更新数据            metaDataDO.setId(exist.getId());            metaDataMapper.update(metaDataDO);            eventType = DataEventTypeEnum.UPDATE;        }        // 发布同步事件到网关        eventPublisher.publishEvent(new DataChangedEvent(ConfigGroupEnum.META_DATA, eventType,                Collections.singletonList(MetaDataTransfer.INSTANCE.mapToData(metaDataDO))));    }
1.4.1.4 注册ContextPath#
   @Override    public String register(final MetaDataRegisterDTO dto) {        //1. 注册选择器        //......                //2. 注册规则        //......                //3. 注册元数据        //......                //4. 注册ContextPath        String contextPath = dto.getContextPath();        if (StringUtils.isNotEmpty(contextPath)) {            registerContextPath(dto);        }        return ShenyuResultMessage.SUCCESS;    }
  • org.apache.shenyu.admin.service.register.AbstractContextPathRegisterService#registerContextPath()
    @Override    public void registerContextPath(final MetaDataRegisterDTO dto) {        // 设置选择器的contextPath        String contextPathSelectorId = getSelectorService().registerDefault(dto, PluginEnum.CONTEXT_PATH.getName(), "");        ContextMappingRuleHandle handle = new ContextMappingRuleHandle();        handle.setContextPath(PathUtils.decoratorContextPath(dto.getContextPath()));        // 设置规则的contextPath        getRuleService().registerDefault(buildContextPathDefaultRuleDTO(contextPathSelectorId, dto, handle.toJson()));    }
1.4.2 注册URI#
  • org.apache.shenyu.admin.service.register.FallbackShenyuClientRegisterService#registerURI()

服务端收到客户端注册的URI信息后，进行处理。

    @Override    public String registerURI(final String selectorName, final List<URIRegisterDTO> uriList) {        String result;        String key = key(selectorName);        try {            this.removeFallBack(key);            // 注册URI            result = this.doRegisterURI(selectorName, uriList);            logger.info("Register success: {},{}", selectorName, uriList);        } catch (Exception ex) {            logger.warn("Register exception: cause:{}", ex.getMessage());            result = "";            // 注册失败后，进行重试            this.addFallback(key, new FallbackHolder(selectorName, uriList));        }        return result;    }
  • org.apache.shenyu.admin.service.register.AbstractShenyuClientRegisterServiceImpl#doRegisterURI()

从客户端注册的URI中获取有效的URI，更新对应的选择器handle属性，向网关发送选择器更新事件。

@Override    public String doRegisterURI(final String selectorName, final List<URIRegisterDTO> uriList) {        //参数检查        if (CollectionUtils.isEmpty(uriList)) {            return "";        }        //获取选择器信息        SelectorDO selectorDO = selectorService.findByNameAndPluginName(selectorName, PluginNameAdapter.rpcTypeAdapter(rpcType()));        if (Objects.isNull(selectorDO)) {            throw new ShenyuException("doRegister Failed to execute,wait to retry.");        }        // 获取有效的URI        List<URIRegisterDTO> validUriList = uriList.stream().filter(dto -> Objects.nonNull(dto.getPort()) && StringUtils.isNotBlank(dto.getHost())).collect(Collectors.toList());        // 构建选择器的handle属性        String handler = buildHandle(validUriList, selectorDO);        if (handler != null) {            selectorDO.setHandle(handler);            SelectorData selectorData = selectorService.buildByName(selectorName, PluginNameAdapter.rpcTypeAdapter(rpcType()));            selectorData.setHandle(handler);            // 向数据库更新选择器的handle属性            selectorService.updateSelective(selectorDO);            // 向网关发送选择器更新事件            eventPublisher.publishEvent(new DataChangedEvent(ConfigGroupEnum.SELECTOR, DataEventTypeEnum.UPDATE, Collections.singletonList(selectorData)));        }        return ShenyuResultMessage.SUCCESS;    }

关于服务注册的源码分析就以及完成了，分析流程图如下：

接下来就分析divide插件是如何根据这些信息向http服务发起调用。

2. 服务调用#

divide插件是网关用于处理 http协议请求的核心处理插件。

以官网提供的案例 Http快速开始 为例，一个直连请求如下：

GET http://localhost:8189/order/findById?id=100Accept: application/json

通过ShenYu网关代理后，请求如下：

GET http://localhost:9195/http/order/findById?id=100Accept: application/json

通过ShenYu网关代理后的服务仍然能够请求到之前的服务，在这里起作用的就是divide插件。类继承关系如下：

  • ShenyuPlugin：顶层接口，定义接口方法；
  • AbstractShenyuPlugin：抽象类，实现插件共有逻辑；
  • DividePlugin：Divide插件。

2.1 接收请求#

通过ShenYu网关代理后，请求入口是ShenyuWebHandler，它实现了org.springframework.web.server.WebHandler接口。

public final class ShenyuWebHandler implements WebHandler, ApplicationListener<SortPluginEvent> {    //......        /**     * 处理web请求     */    @Override    public Mono<Void> handle(@NonNull final ServerWebExchange exchange) {       // 执行默认插件链        Mono<Void> execute = new DefaultShenyuPluginChain(plugins).execute(exchange);        if (scheduled) {            return execute.subscribeOn(scheduler);        }        return execute;    }        private static class DefaultShenyuPluginChain implements ShenyuPluginChain {
        private int index;
        private final List<ShenyuPlugin> plugins;
        /**         * 实例化默认插件链         */        DefaultShenyuPluginChain(final List<ShenyuPlugin> plugins) {            this.plugins = plugins;        }
        /**         * 执行每个插件.         */        @Override        public Mono<Void> execute(final ServerWebExchange exchange) {            return Mono.defer(() -> {                if (this.index < plugins.size()) {                    // 获取当前执行插件                    ShenyuPlugin plugin = plugins.get(this.index++);                    // 是否跳过当前插件                    boolean skip = plugin.skip(exchange);                    if (skip) {                        // 如果跳过就执行下一个                        return this.execute(exchange);                    }                    // 执行当前插件                    return plugin.execute(exchange, this);                }                return Mono.empty();            });        }    }}

2.2 匹配规则#

  • org.apache.shenyu.plugin.base.AbstractShenyuPlugin#execute()

在execute()方法中执行选择器和规则的匹配逻辑。

  • 匹配选择器；
  • 匹配规则；
  • 执行插件。
@Override    public Mono<Void> execute(final ServerWebExchange exchange, final ShenyuPluginChain chain) {        // 插件名称        String pluginName = named();        // 插件信息        PluginData pluginData = BaseDataCache.getInstance().obtainPluginData(pluginName);        if (pluginData != null && pluginData.getEnabled()) {            // 选择器信息            final Collection<SelectorData> selectors = BaseDataCache.getInstance().obtainSelectorData(pluginName);            if (CollectionUtils.isEmpty(selectors)) {                return handleSelectorIfNull(pluginName, exchange, chain);            }            // 匹配选择器            SelectorData selectorData = matchSelector(exchange, selectors);            if (Objects.isNull(selectorData)) {                return handleSelectorIfNull(pluginName, exchange, chain);            }            selectorLog(selectorData, pluginName);            // 规则信息            List<RuleData> rules = BaseDataCache.getInstance().obtainRuleData(selectorData.getId());            if (CollectionUtils.isEmpty(rules)) {                return handleRuleIfNull(pluginName, exchange, chain);            }            // 匹配规则            RuleData rule;            if (selectorData.getType() == SelectorTypeEnum.FULL_FLOW.getCode()) {                //get last                rule = rules.get(rules.size() - 1);            } else {                rule = matchRule(exchange, rules);            }            if (Objects.isNull(rule)) {                return handleRuleIfNull(pluginName, exchange, chain);            }            ruleLog(rule, pluginName);            // 执行插件            return doExecute(exchange, chain, selectorData, rule);        }        return chain.execute(exchange);    }

2.3 执行divide插件#

  • org.apache.shenyu.plugin.divide.DividePlugin#doExecute()

在doExecute()方法中执行divide插件的具体逻辑：

  • 校验header大小；
  • 校验request大小；
  • 获取服务列表；
  • 实现负载均衡；
  • 设置请求url，超时时间，重试策略。
@Override    protected Mono<Void> doExecute(final ServerWebExchange exchange, final ShenyuPluginChain chain, final SelectorData selector, final RuleData rule) {        // 获取上下文信息        ShenyuContext shenyuContext = exchange.getAttribute(Constants.CONTEXT);        assert shenyuContext != null;        // 获取规则的handle属性        DivideRuleHandle ruleHandle = DividePluginDataHandler.CACHED_HANDLE.get().obtainHandle(CacheKeyUtils.INST.getKey(rule));        long headerSize = 0;        // 校验header大小        for (List<String> multiHeader : exchange.getRequest().getHeaders().values()) {            for (String value : multiHeader) {                headerSize += value.getBytes(StandardCharsets.UTF_8).length;            }        }        if (headerSize > ruleHandle.getHeaderMaxSize()) {            LOG.error("request header is too large");            Object error = ShenyuResultWrap.error(exchange, ShenyuResultEnum.REQUEST_HEADER_TOO_LARGE, null);            return WebFluxResultUtils.result(exchange, error);        }                // 校验request大小        if (exchange.getRequest().getHeaders().getContentLength() > ruleHandle.getRequestMaxSize()) {            LOG.error("request entity is too large");            Object error = ShenyuResultWrap.error(exchange, ShenyuResultEnum.REQUEST_ENTITY_TOO_LARGE, null);            return WebFluxResultUtils.result(exchange, error);        }        // 获取服务列表upstreamList        List<Upstream> upstreamList = UpstreamCacheManager.getInstance().findUpstreamListBySelectorId(selector.getId());        if (CollectionUtils.isEmpty(upstreamList)) {            LOG.error("divide upstream configuration error： {}", rule);            Object error = ShenyuResultWrap.error(exchange, ShenyuResultEnum.CANNOT_FIND_HEALTHY_UPSTREAM_URL, null);            return WebFluxResultUtils.result(exchange, error);        }        // 请求ip        String ip = Objects.requireNonNull(exchange.getRequest().getRemoteAddress()).getAddress().getHostAddress();        // 实现负载均衡        Upstream upstream = LoadBalancerFactory.selector(upstreamList, ruleHandle.getLoadBalance(), ip);        if (Objects.isNull(upstream)) {            LOG.error("divide has no upstream");            Object error = ShenyuResultWrap.error(exchange, ShenyuResultEnum.CANNOT_FIND_HEALTHY_UPSTREAM_URL, null);            return WebFluxResultUtils.result(exchange, error);        }        // 设置url        String domain = upstream.buildDomain();        exchange.getAttributes().put(Constants.HTTP_DOMAIN, domain);        // 设置超时时间        exchange.getAttributes().put(Constants.HTTP_TIME_OUT, ruleHandle.getTimeout());        exchange.getAttributes().put(Constants.HTTP_RETRY, ruleHandle.getRetry());        // 设置重试策略        exchange.getAttributes().put(Constants.RETRY_STRATEGY, ruleHandle.getRetryStrategy());        exchange.getAttributes().put(Constants.LOAD_BALANCE, ruleHandle.getLoadBalance());        exchange.getAttributes().put(Constants.DIVIDE_SELECTOR_ID, selector.getId());        return chain.execute(exchange);    }

2.4 发起请求#

默认由WebClientPlugin向http服务发起调用请求，类继承关系如下：

  • ShenyuPlugin：顶层插件，定义插件方法；
  • AbstractHttpClientPlugin：抽象类，实现请求调用的公共逻辑；
  • WebClientPlugin：通过WebClient发起请求；
  • NettyHttpClientPlugin：通过Netty发起请求。

发起请求调用：

  • org.apache.shenyu.plugin.httpclient.AbstractHttpClientPlugin#execute()

在execute()方法中发起请求调用：

  • 获取指定的超时时间，重试次数
  • 发起请求
  • 根据指定的重试策略进行失败后重试操作

public abstract class AbstractHttpClientPlugin<R> implements ShenyuPlugin {
    protected static final Logger LOG = LoggerFactory.getLogger(AbstractHttpClientPlugin.class);
    @Override    public final Mono<Void> execute(final ServerWebExchange exchange, final ShenyuPluginChain chain) {        // 获取上下文信息        final ShenyuContext shenyuContext = exchange.getAttribute(Constants.CONTEXT);        assert shenyuContext != null;        // 获取uri        final URI uri = exchange.getAttribute(Constants.HTTP_URI);        if (Objects.isNull(uri)) {            Object error = ShenyuResultWrap.error(exchange, ShenyuResultEnum.CANNOT_FIND_URL, null);            return WebFluxResultUtils.result(exchange, error);        }        // 获取指定的超时时间        final long timeout = (long) Optional.ofNullable(exchange.getAttribute(Constants.HTTP_TIME_OUT)).orElse(3000L);        final Duration duration = Duration.ofMillis(timeout);        // 获取指定重试次数        final int retryTimes = (int) Optional.ofNullable(exchange.getAttribute(Constants.HTTP_RETRY)).orElse(0);        // 获取指定的重试策略        final String retryStrategy = (String) Optional.ofNullable(exchange.getAttribute(Constants.RETRY_STRATEGY)).orElseGet(RetryEnum.CURRENT::getName);        LOG.info("The request urlPath is {}, retryTimes is {}, retryStrategy is {}", uri.toASCIIString(), retryTimes, retryStrategy);        // 构建header        final HttpHeaders httpHeaders = buildHttpHeaders(exchange);        // 发起请求        final Mono<R> response = doRequest(exchange, exchange.getRequest().getMethodValue(), uri, httpHeaders, exchange.getRequest().getBody())                .timeout(duration, Mono.error(new TimeoutException("Response took longer than timeout: " + duration)))                .doOnError(e -> LOG.error(e.getMessage(), e));                // 重试策略CURRENT，对当前服务进行重试        if (RetryEnum.CURRENT.getName().equals(retryStrategy)) {            //old version of DividePlugin and SpringCloudPlugin will run on this            return response.retryWhen(Retry.anyOf(TimeoutException.class, ConnectTimeoutException.class, ReadTimeoutException.class, IllegalStateException.class)                    .retryMax(retryTimes)                    .backoff(Backoff.exponential(Duration.ofMillis(200), Duration.ofSeconds(20), 2, true)))                    .onErrorMap(TimeoutException.class, th -> new ResponseStatusException(HttpStatus.GATEWAY_TIMEOUT, th.getMessage(), th))                    .flatMap((Function<Object, Mono<? extends Void>>) o -> chain.execute(exchange));        }                // 对其他服务进行重试        // 排除已经调用过的服务        final Set<URI> exclude = Sets.newHashSet(uri);        // 请求重试        return resend(response, exchange, duration, httpHeaders, exclude, retryTimes)                .onErrorMap(TimeoutException.class, th -> new ResponseStatusException(HttpStatus.GATEWAY_TIMEOUT, th.getMessage(), th))                .flatMap((Function<Object, Mono<? extends Void>>) o -> chain.execute(exchange));    }
    private Mono<R> resend(final Mono<R> clientResponse,                           final ServerWebExchange exchange,                           final Duration duration,                           final HttpHeaders httpHeaders,                           final Set<URI> exclude,                           final int retryTimes) {        Mono<R> result = clientResponse;        // 根据指定的重试次数进行重试        for (int i = 0; i < retryTimes; i++) {            result = resend(result, exchange, duration, httpHeaders, exclude);        }        return result;    }
    private Mono<R> resend(final Mono<R> response,                           final ServerWebExchange exchange,                           final Duration duration,                           final HttpHeaders httpHeaders,                           final Set<URI> exclude) {        return response.onErrorResume(th -> {            final String selectorId = exchange.getAttribute(Constants.DIVIDE_SELECTOR_ID);            final String loadBalance = exchange.getAttribute(Constants.LOAD_BALANCE);            //查询可用服务            final List<Upstream> upstreamList = UpstreamCacheManager.getInstance().findUpstreamListBySelectorId(selectorId)                    .stream().filter(data -> {                        final String trimUri = data.getUrl().trim();                        for (URI needToExclude : exclude) {                            // exclude already called                            if ((needToExclude.getHost() + ":" + needToExclude.getPort()).equals(trimUri)) {                                return false;                            }                        }                        return true;                    }).collect(Collectors.toList());            if (CollectionUtils.isEmpty(upstreamList)) {                // no need to retry anymore                return Mono.error(new ShenyuException(ShenyuResultEnum.CANNOT_FIND_HEALTHY_UPSTREAM_URL_AFTER_FAILOVER.getMsg()));            }            // 请求ip            final String ip = Objects.requireNonNull(exchange.getRequest().getRemoteAddress()).getAddress().getHostAddress();            // 实现负载均衡            final Upstream upstream = LoadBalancerFactory.selector(upstreamList, loadBalance, ip);            if (Objects.isNull(upstream)) {                // no need to retry anymore                return Mono.error(new ShenyuException(ShenyuResultEnum.CANNOT_FIND_HEALTHY_UPSTREAM_URL_AFTER_FAILOVER.getMsg()));            }            final URI newUri = RequestUrlUtils.buildRequestUri(exchange, upstream.buildDomain());            // 排除已经调用的uri            exclude.add(newUri);             // 进行再次调用            return doRequest(exchange, exchange.getRequest().getMethodValue(), newUri, httpHeaders, exchange.getRequest().getBody())                    .timeout(duration, Mono.error(new TimeoutException("Response took longer than timeout: " + duration)))                    .doOnError(e -> LOG.error(e.getMessage(), e));        });    }
    //......}
  • org.apache.shenyu.plugin.httpclient.WebClientPlugin#doRequest()

在doRequest()方法中通过webClient发起真正的请求调用。


@Override    protected Mono<ClientResponse> doRequest(final ServerWebExchange exchange, final String httpMethod, final URI uri,                                             final HttpHeaders httpHeaders, final Flux<DataBuffer> body) {        return webClient.method(HttpMethod.valueOf(httpMethod)).uri(uri) //请求uri                .headers(headers -> headers.addAll(httpHeaders)) // 请求header                .body(BodyInserters.fromDataBuffers(body))                .exchange() // 发起请求                .doOnSuccess(res -> {                    if (res.statusCode().is2xxSuccessful()) { // 成功                        exchange.getAttributes().put(Constants.CLIENT_RESPONSE_RESULT_TYPE, ResultEnum.SUCCESS.getName());                    } else { // 失败                        exchange.getAttributes().put(Constants.CLIENT_RESPONSE_RESULT_TYPE, ResultEnum.ERROR.getName());                    }                    exchange.getResponse().setStatusCode(res.statusCode());                    exchange.getAttributes().put(Constants.CLIENT_RESPONSE_ATTR, res);                });    }

2.5 处理响应结果#

  • org.apache.shenyu.plugin.response.ResponsePlugin#execute()

响应结果由ResponsePlugin插件处理。

    @Override    public Mono<Void> execute(final ServerWebExchange exchange, final ShenyuPluginChain chain) {        ShenyuContext shenyuContext = exchange.getAttribute(Constants.CONTEXT);        assert shenyuContext != null;        // 根据rpc类型处理结果        return writerMap.get(shenyuContext.getRpcType()).writeWith(exchange, chain);    }

处理类型由MessageWriter决定，类继承关系如下：

  • MessageWriter：接口，定义消息处理方法；
  • NettyClientMessageWriter：处理Netty调用结果；
  • RPCMessageWriter：处理RPC调用结果；
  • WebClientMessageWriter：处理WebClient调用结果；

默认是通过WebCient发起http请求。

  • org.apache.shenyu.plugin.response.strategy.WebClientMessageWriter#writeWith()

在writeWith()方法中处理响应结果。


    @Override    public Mono<Void> writeWith(final ServerWebExchange exchange, final ShenyuPluginChain chain) {        return chain.execute(exchange).then(Mono.defer(() -> {            // 获取响应            ServerHttpResponse response = exchange.getResponse();            ClientResponse clientResponse = exchange.getAttribute(Constants.CLIENT_RESPONSE_ATTR);            if (Objects.isNull(clientResponse)) {                Object error = ShenyuResultWrap.error(exchange, ShenyuResultEnum.SERVICE_RESULT_ERROR, null);                return WebFluxResultUtils.result(exchange, error);            }            //获取cookies和headers            response.getCookies().putAll(clientResponse.cookies());            response.getHeaders().putAll(clientResponse.headers().asHttpHeaders());            // image, pdf or stream does not do format processing.            // 处理特殊响应类型            if (clientResponse.headers().contentType().isPresent()) {                final String media = clientResponse.headers().contentType().get().toString().toLowerCase();                if (media.matches(COMMON_BIN_MEDIA_TYPE_REGEX)) {                    return response.writeWith(clientResponse.body(BodyExtractors.toDataBuffers()))                            .doOnCancel(() -> clean(exchange));                }            }            // 处理一般响应类型            clientResponse = ResponseUtils.buildClientResponse(response, clientResponse.body(BodyExtractors.toDataBuffers()));            return clientResponse.bodyToMono(byte[].class)                    .flatMap(originData -> WebFluxResultUtils.result(exchange, originData))                    .doOnCancel(() -> clean(exchange));        }));    }

分析至此，关于Divide插件的源码分析就完成了，分析流程图如下：

3. 小结#

本文源码分析从http服务注册开始，到divide插件的服务调用。divide插件主要用来处理http请求。有些源码没有进入深入分析，比如负载均衡的实现，服务探活，将在后续继续分析。