sentinel/sentinel-adapter/sentinel-spring-webmvc-adapter

Sentinel Spring MVC Interceptor

Sentinel provides Spring MVC Interceptor integration to enable flow control for web requests, And support url like ‘/foo/{id}’

Add the following dependency in pom.xml (if you are using Maven):

<dependency>
    <groupId>com.alibaba.csp</groupId>
    <artifactId>sentinel-spring-webmvc-adapter</artifactId>
    <version>x.y.z</version>
</dependency>

Configure interceptor

@Configuration
public class InterceptorConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //Add sentinel interceptor
        addSpringMvcInterceptor(registry);
        //If you want to sentinel the total flow, you can add total interceptor
        addSpringMvcTotalInterceptor(registry);
    }

    private void addSpringMvcInterceptor(InterceptorRegistry registry) {
        //Configure
        SentinelWebMvcConfig config = new SentinelWebMvcConfig();
        //Custom configuration if necessary
        config.setHttpMethodSpecify(true);
        config.setOriginParser(request -> request.getHeader("S-user"));
        //Add sentinel interceptor
        registry.addInterceptor(new SentinelInterceptor(config)).addPathPatterns("/**");
    }

    private void addSpringMvcTotalInterceptor(InterceptorRegistry registry) {
        //Configure
        SentinelWebMvcTotalConfig config = new SentinelWebMvcTotalConfig();
        //Custom configuration if necessary
        config.setRequestAttributeName("my_sentinel_spring_mvc_total_entity_container");
        config.setTotalResourceName("my-spring-mvc-total-url-request");
        //Add sentinel interceptor
        registry.addInterceptor(new SentinelTotalInterceptor(config)).addPathPatterns("/**");
    }
}

Configure ‘BlockException’ handler, there are three options:

1. Global exception handling in spring MVC.

   @ControllerAdvice
   @Order(0)
   public class SentinelSpringMvcBlockHandlerConfig {
   private Logger logger = LoggerFactory.getLogger(this.getClass());
   @ExceptionHandler(BlockException.class)
   @ResponseBody
   public String sentinelBlockHandler(BlockException e) {
       AbstractRule rule = e.getRule();
       logger.info("Blocked by sentinel, {}", rule.toString());
       return "Blocked by Sentinel";
   }
   }
   

   1. Use DefaultBlockExceptionHandler java //SentinelWebMvcTotalConfig config = new SentinelWebMvcTotalConfig(); SentinelWebMvcConfig config = new SentinelWebMvcConfig(); config.setBlockExceptionHandler(new DefaultBlockExceptionHandler());

2. implements BlockExceptionHandler

   //SentinelWebMvcTotalConfig config = new SentinelWebMvcTotalConfig();
   SentinelWebMvcConfig config = new SentinelWebMvcConfig();
   config.setBlockExceptionHandler((request, response, e) -> {
   String resourceName = e.getRule().getResource();
   //Depending on your situation, you can choose to process or throw
   if ("/hello".equals(resourceName)) {
       //Do something ......
       //Write string or error page;
       response.getWriter().write("Blocked by sentinel");
   } else {
       //Handle it in global exception handling
       throw e;
   }
   });
   

   Configuration

   • Common configuration in SentinelWebMvcConfig and SentinelWebMvcTotalConfig | name | description | type | default value | |------|------------|------|-------| | blockExceptionHandler| The handler when blocked by sentinel, there are three options:
     1. The default value is null, you can hanlde BlockException in spring MVC;
     2.Use DefaultBlockExceptionHandler;
     3. implements BlockExceptionHandler | BlockExceptionHandler | null | | originParser | RequestOriginParser interface is useful for extracting request origin (e.g. IP or appName from HTTP Header) from HTTP request | RequestOriginParser | null |
   • SentinelWebMvcConfig configuration | name | description | type | default value | |------|------------|------|-------| | urlCleaner | The UrlCleaner interface is designed for clean and unify the URL resource. For REST APIs, you can to clean the URL resource (e.g. /api/user/getById and /api/user/getByName -> /api/user/getBy*), avoid the amount of context and will exceed the threshold | UrlCleaner | null | | requestAttributeName | Attribute name in request used by sentinel, please check record log, if it is already used, please set | String | sentinel_spring_mvc_entry_container | | httpMethodSpecify | Specify http method, for example: GET:/hello | boolean | false | SentinelWebMvcTotalConfig configuration | name | description | type | default value | |------|------------|------|-------| | totalResourceName | The resource name in SentinelTotalInterceptor | String | spring-mvc-total-url-request | | requestAttributeName | Attribute name in request used by sentinel, please check record log, if it is already used, please set | String | sentinel_spring_mvc_total_entry_container |