https://github.com/jmnarloch/feign-vnderror-spring-cloud-starter

Spring Cloud Feign vnd.error decoder
https://github.com/jmnarloch/feign-vnderror-spring-cloud-starter

Last synced: 4 days ago
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Spring Cloud Feign vnd.error decoder

• Host: GitHub
• URL: https://github.com/jmnarloch/feign-vnderror-spring-cloud-starter
• Owner: jmnarloch
• License: apache-2.0
• Created: 2015-08-18T18:32:38.000Z (about 9 years ago)
• Default Branch: master
• Last Pushed: 2015-12-25T13:55:50.000Z (almost 9 years ago)
• Last Synced: 2023-05-25T06:46:22.233Z (over 1 year ago)
• Language: Java
• Homepage:
• Size: 97.7 KB
• Stars: 9
• Watchers: 2
• Forks: 9
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Spring Cloud Netflix Feign vnd.error decoder

> A custom error decoder for Netflix Feign that will unmarshall [vnd.error](https://github.com/blongden/vnd.error).

[![Build Status](https://travis-ci.org/jmnarloch/feign-vnderror-spring-cloud-starter.svg?branch=master)](https://travis-ci.org/jmnarloch/feign-vnderror-spring-cloud-starter)

[![Coverage Status](https://coveralls.io/repos/jmnarloch/feign-vnderror-spring-cloud-starter/badge.svg?branch=master&service=github)](https://coveralls.io/github/jmnarloch/feign-vnderror-spring-cloud-starter?branch=master)

## Features

A custom Feign ErrorDecoder capable of handling JSON vnd.error responses. 

## Setup

Add the Spring Cloud starter to your project:

```xml

  com.github.jmnarloch

  feign-vnderror-spring-cloud-starter

  1.2.0

```

## Usage

First on server side make sure that your exception handling logic will return VndErrors 

(this is part of Spring Hateoas project). 

You can accomplish that by registering custom `@ExceptionHandler` in your application

```java

@ExceptionHandler

ResponseEntity someExceptionHandler(SomeException e) {

    String logref = UUID.randomUUID();

    

    HttpHeaders httpHeaders = new HttpHeaders();

    httpHeaders.setContentType(MediaType.parseMediaType("application/vnd.error+json"));

    return new ResponseEntity<>(new VndErrors(logref, e.getMessage()), httpHeaders, HttpStatus.INTERNAL_SERVER_ERROR);

}

```

Place it in your `@Controller` or `@ControllerAdvice` annotated beans. You can populate the logref with some 

meaningful identifier that afterwards could be used during log analysis. Generally it could be a good idea to add 

[HandlerInterceptor](http://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/web/servlet/HandlerInterceptor.html) 

to populate request scoped identifier on `preHandle()`.

 

The error decoding happens base on content type matching so it is crucial to return `application/vnd.error+json` as 

response content type.

You use your Feign clients in the same manner as in any other cases, the only difference is that whenever a client call 

will end with vnd.error you should expect `VndErrorException` instead of `FeignException`.

Example:

```java

try {

    feignClient.operation();    

} catch (VndErrorException exc) {

    ...

}

```

The `VndErrorException` makes very convenient to passthrough exceptions, if you call remote service from a web 

application you can register `@ExceptionHandler` and return the original vnd.error retrieved from the `VndErrorException`. 

## Properties

```

feign.vnderror.enabled=true # whether to enable the vnd error decoder, true by default

```

## Migration to 1.2.x

The VndErrorException has been reworked to include extra request information like http status, http headers and

response body, replacing the existing exception constructors.

Also effort has been made to include the exception type directly in Spring HATEOAS.

## License

Apache 2.0