This tutorial is going to illustrate how to do basic authentication with Open Feign, a java to http client binder powered by OpenFiegn.
1. Overview
In general, we will use the BasicAuthRequestInterceptor class, which is an interceptor that adds the request header needed to use HTTP basic authentication, for basic authentication purposes.
In this tutorial, let’s assume that we will consume a REST API that requires basic authentication on the https://httpbin.org/, a HTTP Client Testing Service. The REST API which returns the current authenticated user and status, can be described as below:
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GET https://httpbin.org/basic-auth/user/passwd |
Responses: application/json
Example:
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{ "authenticated": true, "user": "user" } |
STATUS 200 if get resource successfully.
STATUS 401 if not authorized.
2. The source code
In this tutorial, we will use the Feign version: 8.18.0. The Maven dependencies are as below:
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<dependencies> <!-- Begin Netflix Feign dependencies --> <dependency> <groupId>com.netflix.feign</groupId> <artifactId>feign-core</artifactId> <version>8.18.0</version> </dependency> <dependency> <groupId>com.netflix.feign</groupId> <artifactId>feign-jackson</artifactId> <version>8.18.0</version> </dependency> <!-- End Netflix Feign dependencies --> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.8.1</version> <scope>test</scope> </dependency> </dependencies> |
The source code can be found on Github or you can download it via the link:java-examples.zip
3. Basic Authentication with Open Feign
3.1. Define a Proxy Interface at the client side
Firstly, we need to define a proxy interface which contains all methods targeted with the REST API. Let’s see how the interface is defined as below:
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@Headers("Accept: application/json") interface HttpBinResource { @RequestLine("GET /basic-auth/user/passwd") AuthStatus getAuthenticatedUser(); } |
For more detail, you can refer to my recent post about implementing Java REST client using Feign.
As for the response, we also need to define a class to bind with it. Let’s see how it is defined:
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public class AuthStatus { private boolean authenticated; private String user; //getters and setters are omitted for shortly } |
3.2. Invoke methods on the Proxy
Now we will invoke the method defined on the Proxy Interface. Note that the method require basic authentication. Let’s see an example code:
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public class RequestReponseService { private static final String HTTP_BIN_URL = "http://httpbin.org/"; public static final String USERNAME = "user"; public static final String PASSWORD = "passwd"; public AuthStatus getAuthenticatedUser() { BasicAuthRequestInterceptor interceptor = new BasicAuthRequestInterceptor(USERNAME, PASSWORD); HttpBinResource bookResource = Feign.builder().encoder(new JacksonEncoder()) .decoder(new JacksonDecoder()).requestInterceptor(interceptor) .target(HttpBinResource.class, HTTP_BIN_URL); return bookResource.getAuthenticatedUser(); } } |
Here are some essential points:
- We create a instance of the BasicAuthRequestInterceptor with default username and password for basic authentication with the REST API and set it as a request interceptor of the Feign targeted http apis.
- We use JacksonEncoder to convert the response into our AuthStatus object.
3.3. Verify
Let’s write a piece of unit test for the method:
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public class TestRequestReponseService { @Test public void testAuthenticate() { RequestReponseService service = new RequestReponseService(); AuthStatus authStatus = service.getAuthenticatedUser(); assertEquals(authStatus.getUser(), RequestReponseService.USERNAME); assertTrue(authStatus.isAuthenticated()); } } |
Running the test will give the Green color.
4. Conclusion
The tutorial has just shown you how to do basic authentication with Open Feign by using the BasicAuthRequestInterceptor class as a request interceptor. Beside, there are other approaches to do basic authentication and we will get to know in next posts. Here are other related articles:
Java REST Client Using Netflix Feign
File Uploading with Open Feign