openfeign / feign-cdi

CDI provider for injecting Feign types

Feign CDI

Integration for OpenFeign with Java Contexts & Dependency Injection, allowing you to inject your type safe restful interfaces

Adding to your project

Feign CDI is built using Apache Maven. Artifacts are published, though there's only a single artifact at this time.

<dependency>
    <groupId>io.github.openfeign.cdi</groupId>
    <artifactId>feign-cdi</artifactId>
    <version>0.1.6</version>
</dependency>

Creating clients

Feign CDI uses the normal Feign interfaces for declaring your rest client. You can add additional annotations to your interface to support CDI integration

@FeignClient

public @interface FeignClient {
    Logger.Level logLevel() default Logger.Level.NONE;

    Class<? extends Contract> contract() default Contract.Default.class;

    Class<? extends Client> client() default CDIClient.class;

    Class<? extends Decoder> decoder() default Decoder.Default.class;

    Class<? extends Encoder> encoder() default Encoder.Default.class;

    Class<? extends ErrorDecoder> errorDecoder() default ErrorDecoder.Default.class;

    Class<? extends InvocationHandlerFactory> invocationHandlerFactory() default InvocationHandlerFactory.Default.class;

    Class<? extends Logger> logger() default Logger.NoOpLogger.class;

    Class<? extends Retryer> retryer() default Retryer.Default.class;

    Class<? extends RequestInterceptor>[] requestInterceptors() default {};

    String url();

    int connectTimeoutMillis() default 10 * 1000;

    int readTimeoutMillis() default 60 * 1000;

    boolean decode404() default false;
}

@FeignClient is an annotation to place on your interfaces where you can define the normal configuration options for Feign interfaces. The defaults here match the defaults in Feign.Builder, except for the client implementation to support no-arg constructors.

Any class configured here will follow one of two options:

• Managed CDI Beans
• No-args constructor

Any classes you use here should be normal scoped beans - don't use @Dependent as there is no creational context. If no bean is found, then this extension will instantiate the class using its default constructor.

Managing Scopes

Any @Scope declared on the interface will be used by the bean.

Registering the extension

The CDI extension class to register is feign.cdi.impl.FeignExtension, which will add annotated client beans for each interface discovered.

feign-cdi's Issues

Feign CDI - Optional Hystrix Integration

Add support for the optional capabilities provided in Hystrix module. Since the module provides its own builder, need to leverage that builder instead of the native builder.

CDI module has an error when looking for the bean scope

There are an error in the Feign CDI module, when the producer bean tries to get the bean client scope annotation.

Calling getClass() on an annotation may return a proxy class instead of wanted class.

Related pull request: #7
Related issue: OpenFeign/feign#925

Implement a Feign CDI Module

From @johnament on December 4, 2016 13:30

Feign is an amazing library for working with type safe REST clients. It simplifies a lot of day to day development work being able to leverage the client.

CDI is a dependency injection tool. While a user can define producer methods there is still the boilerplate overhead that they may have to deal with.

I'd like to propose adding a CDI module, which will look for interfaces supporting Feign and provide injection points to CDI users to simply inject their clients. No additional development, all annotation based and configured as needed.

It should provide some kind of fallback to look for common builders for interfaces and leverage those whenever possible.

Copied from original issue: OpenFeign/feign#500

Feign CDI - Core Feign Integration

Provide some core Feign integration - able to create injection targets based on properly annotated feign interfaces.

Feign CDI - Allow building from a produced instance.

Instead of expecting all config in annotations, we should also support produced instances.

The @FeignClient not have responseInterceptor method