Merge pull request #48 from Mastercard/feature/webflux-support

Adding webflux support

Author: danny-gallagher

README.md

@@ -96,6 +96,7 @@ Usage briefly described below, but you can also refer to the test package for ex
 + [Java HttpsURLConnection](#java-httpsurlconnection)
 + [Apache HTTP Client 4](#apache-http-client-4)
 + [OkHttp 3](#okhttp-3)
++ [Spring Webflux](#spring-webflux)
 
 #### Java HttpsURLConnection <a name="java-httpsurlconnection"></a>
 ```java
@@ -138,6 +139,19 @@ OkHttpSigner signer = new OkHttpSigner(consumerKey, signingKey);
 signer.sign(request);
 ```
 
+#### Spring Webflux <a name="spring-webflux"></a>
+```java
+WebClient client = WebClient.create();
+ClientRequest request = ClientRequest.create(HttpMethod.POST, URI.create("https://api.mastercard.com/service"))
+        .header("Content-Type", MediaType.APPLICATION_JSON_VALUE)
+        .body(BodyInserters.fromValue(yourRequestObject))
+        .build();
+
+SpringWebfluxSigner signer = new SpringWebfluxSigner(consumerKey, signingKey);
+ClientRequest signedRequest = signer.sign(request);
+client.exchange(signedRequest);
+```
+
 ### Integrating with OpenAPI Generator API Client Libraries <a name="integrating-with-openapi-generator-api-client-libraries"></a>
 
 [OpenAPI Generator](https://github.com/OpenAPITools/openapi-generator) generates API client libraries from [OpenAPI Specs](https://github.com/OAI/OpenAPI-Specification). 
@@ -151,6 +165,7 @@ Library options currently supported for the `java` generator:
 + [retrofit](#retrofit)
 + [retrofit2](#retrofit2)
 + [google-api-client](#google-api-client)
++ [spring-webflux](#spring-webflux-interceptor)
 
 See also:
 * [OpenAPI Generator (maven Plugin)](https://mvnrepository.com/artifact/org.openapitools/openapi-generator-maven-plugin)
@@ -284,3 +299,25 @@ ApiClient client = new ApiClient("https://sandbox.api.mastercard.com", null, ini
 ServiceApi serviceApi = client.serviceApi();
 // ...
 ```
+
+#### spring-webflux <a name="spring-webflux-interceptor"></a>
+##### OpenAPI Generator Plugin Configuration
+```xml
+<configuration>
+    <inputSpec>${project.basedir}/src/main/resources/openapi-spec.yaml</inputSpec>
+    <generatorName>spring</generatorName>
+    <library>spring-cloud</library>
+    <!-- ... -->
+</configuration>
+```
+
+##### Usage of the `HttpExecuteOAuth1Interceptor`
+```java
+WebClient.Builder webClientBuilder = WebClient.builder()
+  .baseUrl("https://api.mastercard.com/service")
+  .filter(new SpringWebfluxOAuth1Interceptor(consumerKey, signingKey));
+
+ApiClient apiClient = new ApiClient(webClientBuilder);
+ServiceApi serviceApi = client.serviceApi();
+// ...
+```

pom.xml

@@ -14,6 +14,7 @@
 
     <properties>
         <spring-version>5.3.33</spring-version>
+        <spring-webflux-version>3.5.3</spring-webflux-version>
         <okhttp2-version>2.7.5</okhttp2-version>
         <okhttp3-version>4.12.0</okhttp3-version>
         <google-api-client-version>2.3.0</google-api-client-version>
@@ -85,6 +86,13 @@
             <scope>provided</scope>
         </dependency>
 
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-webflux</artifactId>
+            <version>${spring-webflux-version}</version>
+            <scope>provided</scope>
+        </dependency>
+
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>

src/main/java/com/mastercard/developer/interceptors/SpringWebfluxOAuth1Interceptor.java

@@ -0,0 +1,32 @@
+package com.mastercard.developer.interceptors;
+
+import com.mastercard.developer.signers.SpringWebfluxSigner;
+import org.springframework.web.reactive.function.client.ClientRequest;
+import org.springframework.web.reactive.function.client.ClientResponse;
+import org.springframework.web.reactive.function.client.ExchangeFilterFunction;
+import org.springframework.web.reactive.function.client.ExchangeFunction;
+import reactor.core.publisher.Mono;
+
+import java.security.PrivateKey;
+
+/**
+ * A Spring webflux request interceptor for handling OAuth1.0a
+ */
+public class SpringWebfluxOAuth1Interceptor implements ExchangeFilterFunction {
+
+    private final SpringWebfluxSigner signer;
+
+    public SpringWebfluxOAuth1Interceptor(String consumerKey, PrivateKey signingKey) {
+        this.signer = new SpringWebfluxSigner(consumerKey, signingKey);
+    }
+
+    @Override
+    public Mono<ClientResponse> filter(ClientRequest request, ExchangeFunction next) {
+        try {
+            ClientRequest req = signer.sign(request);
+            return next.exchange(req).doOnNext(response -> {});
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+}

src/main/java/com/mastercard/developer/signers/SpringWebfluxSigner.java

@@ -0,0 +1,30 @@
+package com.mastercard.developer.signers;
+
+import com.mastercard.developer.oauth.OAuth;
+import org.springframework.web.reactive.function.client.ClientRequest;
+import reactor.core.publisher.Mono;
+
+import java.net.URI;
+import java.security.PrivateKey;
+
+/**
+ * Utility class for signing Spring webflux requests
+ */
+public class SpringWebfluxSigner extends AbstractSigner {
+
+    public SpringWebfluxSigner(String consumerKey, PrivateKey signingKey) {
+        super(consumerKey, signingKey);
+    }
+
+    public ClientRequest sign(ClientRequest request) throws Exception {
+        URI uri = request.url();
+        String method = request.method().name();
+
+        String authHeader = OAuth.getAuthorizationHeader(uri, method, request.body().toString(), charset, consumerKey, signingKey);
+
+        // Add auth header
+        return Mono.just(ClientRequest.from(request)
+                .headers(headers -> headers.add(OAuth.AUTHORIZATION_HEADER_NAME, authHeader))
+                .build()).block();
+    }
+}

src/test/java/com/mastercard/developer/signers/SpringWebfluxSignerTest.java

@@ -0,0 +1,40 @@
+package com.mastercard.developer.signers;
+
+import com.squareup.okhttp.MediaType;
+import com.squareup.okhttp.RequestBody;
+import org.junit.Assert;
+import org.junit.Test;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.ReactiveHttpOutputMessage;
+import org.springframework.web.reactive.function.BodyInserter;
+import org.springframework.web.reactive.function.BodyInserters;
+import org.springframework.web.reactive.function.client.ClientRequest;
+
+import java.net.URI;
+import java.security.PrivateKey;
+
+import static com.mastercard.developer.test.TestUtils.UTF8_CHARSET;
+import static com.mastercard.developer.test.TestUtils.getTestSigningKey;
+
+public class SpringWebfluxSignerTest {
+
+    @Test
+    public void testSign_ShouldAddOAuth1HeaderToPostRequest() throws Exception {
+
+        // GIVEN
+        PrivateKey signingKey = getTestSigningKey();
+        String consumerKey = "Some key";
+        MediaType jsonMediaType = MediaType.parse("application/json; charset=" + UTF8_CHARSET.name());
+        RequestBody body = RequestBody.create(jsonMediaType, "{\"foo\":\"bår\"}");
+        BodyInserter<RequestBody, ReactiveHttpOutputMessage> inserter = BodyInserters.fromValue(body);
+        ClientRequest request = ClientRequest.create(HttpMethod.GET, URI.create("https://api.mastercard.com/service")).body(inserter).build();
+
+        // WHEN
+        SpringWebfluxSigner instanceUnderTest = new SpringWebfluxSigner(consumerKey, signingKey);
+        ClientRequest signedRequest = instanceUnderTest.sign(request);
+
+        // THEN
+        String authorizationHeaderValue = signedRequest.headers().getFirst("Authorization");
+        Assert.assertNotNull(authorizationHeaderValue);
+    }
+}