feign.interceptor

Interface MethodInterceptor

@Experimental
public interface MethodInterceptor

An around-style interceptor invoked once per method call, after the Contract has resolved the RequestTemplate from method arguments and before RequestInterceptors mutate it. Implementations have full access to the raw method arguments, the MethodMetadata, the resolved RequestTemplate (headers, query params, body bytes), and after MethodInterceptor.Chain.next(Invocation) completes successfully, the Response via Invocation.response().

Use this extension point when RequestInterceptor or ResponseInterceptor are not enough — typically when you need both the typed argument objects (e.g. for validation) and the resolved request, or when you need to short-circuit the entire HTTP exchange and return a value without sending a request.

Short-circuit: simply return a value without calling MethodInterceptor.Chain.next(Invocation).

Exception propagation: any Throwable thrown surfaces to the caller of the Feign interface method, after retry handling.

 public Object intercept(Invocation invocation, Chain chain) throws Throwable {
   validate(invocation.arguments());
   return chain.next(invocation);
 }
 

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	MethodInterceptor.Chain Contract for delegation to the rest of the chain.

Method Summary

Modifier and Type	Method and Description
default MethodInterceptor	andThen(MethodInterceptor next) Returns a new MethodInterceptor that invokes the current interceptor first and then the one passed in.
default MethodInterceptor.Chain	apply(MethodInterceptor.Chain chain) Apply this interceptor to the given chain, producing a chain that runs this interceptor first.
Object	intercept(Invocation invocation, MethodInterceptor.Chain chain) Called for every method invocation on a Feign-built proxy.

Method Detail

intercept

Object intercept(Invocation invocation,
                 MethodInterceptor.Chain chain)
          throws Throwable

Called for every method invocation on a Feign-built proxy.

Parameters:

invocation - context for the current method call

chain - delegate to invoke the rest of the pipeline (request interceptors, HTTP, response interceptors, decoder)

Returns:

the value to return from the proxied method

Throws:

Throwable

apply

default MethodInterceptor.Chain apply(MethodInterceptor.Chain chain)

Apply this interceptor to the given chain, producing a chain that runs this interceptor first.

andThen

default MethodInterceptor andThen(MethodInterceptor next)

Returns a new MethodInterceptor that invokes the current interceptor first and then the one passed in.