Package org.apache.ignite.services

Interface ServiceCallInterceptor

  • All Superinterfaces:
    Serializable
    public interface ServiceCallInterceptor
extends Serializable
    Service call interceptor.

    Allows the user to intercept the call to any service method except lifecycle methods (init(), execute() and cancel()).

    A typical use of an interceptor is a middleware logic that applies to all custom methods in a service. The user can specify multiple interceptors in the service configuration. Each interceptor invokes the next interceptor in the chain using a delegated call, the last interceptor will call the service method.

    Usage example: 

     ServiceCallInterceptor security = (mtd, args, ctx, svcCall) -> {
     if (!CustomSecurityProvider.get().access(mtd, ctx.currentCallContext().attribute("sessionId")))
         throw new SecurityException("Method invocation is not permitted");

     // Execute remaining interceptors and service method.
     return svcCall.call();
 };

 ServiceCallInterceptor audit = (mtd, args, ctx, svcCall) -> {
     String sessionId = ctx.currentCallContext().attribute("sessionId");
     AuditProvider prov = AuditProvider.get();

     // Record an event before execution of the method.
     prov.recordStartEvent(ctx.name(), mtd, sessionId);

     try {
         // Execute service method.
         return svcCall.call();
     }
     catch (Exception e) {
         // Record error.
         prov.recordError(ctx.name(), mtd, sessionId), e.getMessage());

         // Re-throw exception to initiator.
         throw e;
     }
     finally {
         // Record finish event after execution of the service method.
         prov.recordFinishEvent(ctx.name(), mtd, sessionId);
     }
 }

 ServiceConfiguration svcCfg = new ServiceConfiguration()
     .setName("service")
     .setService(new MyServiceImpl())
     .setMaxPerNodeCount(1)
     .setInterceptors(audit, security);

 // Deploy service.
 ignite.services().deploy(svcCfg);

 // Set context parameters for the service proxy.
 ServiceCallContext callCtx = ServiceCallContext.builder().put("sessionId", sessionId).build();

 // Make a service proxy with the call context to define the "sessionId" attribute.
 MyService proxy = ignite.services().serviceProxy("service", MyService.class, false, callCtx, 0);

 // Service method call will be intercepted.
 proxy.placeOrder(order1);
 proxy.placeOrder(order2);
    See Also:
    ServiceCallContext, ServiceContext

    • Method Detail

      • invoke

        Object invoke​(String mtd,
              Object[] args,
              ServiceContext ctx,
              Callable<Object> next)
       throws Exception
        Intercepts delegated service call.
        Parameters:
        mtd - Method name.
        args - Method arguments.
        ctx - Service context.
        next - Delegated call to a service method and/or interceptor in the chain.
        Returns:
        Service call result.
        Throws:
        Exception