Package com.linecorp.armeria.resilience4j.circuitbreaker.client

Class Resilience4JCircuitBreakerClientHandler

java.lang.Object

com.linecorp.armeria.resilience4j.circuitbreaker.client.Resilience4JCircuitBreakerClientHandler

All Implemented Interfaces:

CircuitBreakerClientHandler

@UnstableApi
public final class Resilience4JCircuitBreakerClientHandler
extends Object
implements CircuitBreakerClientHandler

A CircuitBreakerClientHandler implementation for use with Resilience4j's CircuitBreaker.

 // for HttpRequest
 CircuitBreakerRule rule = CircuitBreakerRule.onStatusClass(HttpStatusClass.SERVER_ERROR);
 CircuitBreakerRegistry registry = CircuitBreakerRegistry.ofDefaults();
 Resilience4jCircuitBreakerMapping mapping =
     Resilience4jCircuitBreakerMapping.builder()
                                      .registry(registry)
                                      .perHost()
                                      .build();
 WebClient.builder()
          .decorator(CircuitBreakerClient.newDecorator(
              Resilience4JCircuitBreakerClientHandler.of(mapping), rule))
          ...

 // for RpcRequest
 CircuitBreakerRuleWithContent rule = ...;
 CircuitBreakerRegistry registry = CircuitBreakerRegistry.ofDefaults();
 Resilience4jCircuitBreakerMapping mapping =
     Resilience4jCircuitBreakerMapping.builder()
                                      .registry(registry)
                                      .perHost()
                                      .build();
 ThriftClients.builder("http://thrift.api.com")
              .rpcDecorator(CircuitBreakerRpcClient.newDecorator(
                  Resilience4JCircuitBreakerClientHandler.of(mapping), rule))
              ...
 

Method Summary

Modifier and Type	Method	Description
boolean	isCircuitBreakerException(Exception ex)	Determines if the given Exception is related to a circuit breaker.
static CircuitBreakerClientHandler	of()	Creates a default CircuitBreakerClientHandler which uses Resilience4jCircuitBreakerMapping.of() to handle requests.
static CircuitBreakerClientHandler	of(Resilience4jCircuitBreakerMapping mapping)	Creates a default CircuitBreakerClientHandler which uses the provided CircuitBreakerMapping to handle requests.
static CircuitBreakerClientHandler	of(io.github.resilience4j.circuitbreaker.CircuitBreaker circuitBreaker)	Creates a default CircuitBreakerClientHandler which uses the provided CircuitBreaker to handle requests.
CircuitBreakerCallback	tryRequest(ClientRequestContext ctx, Request req)	Invoked by CircuitBreakerClient right before sending a request.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

of

public static CircuitBreakerClientHandler of()

Creates a default CircuitBreakerClientHandler which uses Resilience4jCircuitBreakerMapping.of() to handle requests.

of

public static CircuitBreakerClientHandler of(io.github.resilience4j.circuitbreaker.CircuitBreaker circuitBreaker)

Creates a default CircuitBreakerClientHandler which uses the provided CircuitBreaker to handle requests.

of

public static CircuitBreakerClientHandler of(Resilience4jCircuitBreakerMapping mapping)

Creates a default CircuitBreakerClientHandler which uses the provided CircuitBreakerMapping to handle requests.

tryRequest

public CircuitBreakerCallback tryRequest(ClientRequestContext ctx,
 Request req)

Description copied from interface: CircuitBreakerClientHandler

Invoked by CircuitBreakerClient right before sending a request. In a typical implementation, users may extract the appropriate circuit breaker implementation using the provided ClientRequestContext and Request. Afterwards, one of the following can occur:

• If the circuit breaker rejects the request, an exception such as FailFastException may be thrown.
• If the circuit breaker doesn't reject the request, users may choose to return a CircuitBreakerCallback. A callback method will be invoked depending on the configured CircuitBreakerRule.
• One may return null to proceed normally as if the CircuitBreakerClient doesn't exist.

Specified by:

tryRequest in interface CircuitBreakerClientHandler

isCircuitBreakerException

public boolean isCircuitBreakerException(Exception ex)

Description copied from interface: CircuitBreakerClientHandler

Determines if the given Exception is related to a circuit breaker. This method is invoked by the CircuitBreakerClient to determine if a fallback logic should be executed.

Specified by:

isCircuitBreakerException in interface CircuitBreakerClientHandler