Add support for a token supplier to OAuth based RestClient clients. (#19944)

Fixes OpenAPITools#19943

modules/openapi-generator/src/main/resources/Java/libraries/restclient/auth/OAuth.mustache

@@ -2,25 +2,49 @@
 
 package {{invokerPackage}}.auth;
 
+import java.util.Optional;
+import java.util.function.Supplier;
 import org.springframework.http.HttpHeaders;
 import org.springframework.util.MultiValueMap;
 
+/**
+ * Provides support for RFC 6750 - Bearer Token usage for OAUTH 2.0 Authorization.
+ */
 {{>generatedAnnotation}}
 public class OAuth implements Authentication {
-    private String accessToken;
+    private Supplier<String> tokenSupplier;
 
+    /**
+     * Returns the bearer token used for Authorization.
+     *
+     * @return The bearer token
+     */
     public String getAccessToken() {
-        return accessToken;
+        return tokenSupplier.get();
     }
 
+    /**
+     * Sets the bearer access token used for Authorization.
+     *
+     * @param accessToken The bearer token to send in the Authorization header
+     */
     public void setAccessToken(String accessToken) {
-        this.accessToken = accessToken;
+        setAccessToken(() -> accessToken);
+    }
+
+    /**
+     * Sets the supplier of bearer tokens used for Authorization.
+     *
+     * @param tokenSupplier The supplier of bearer tokens to send in the Authorization header
+     */
+    public void setAccessToken(Supplier<String> tokenSupplier) {
+        this.tokenSupplier = tokenSupplier;
     }
 
     @Override
     public void applyToParams(MultiValueMap<String, String> queryParams, HttpHeaders headerParams, MultiValueMap<String, String> cookieParams) {
-        if (accessToken != null) {
+        Optional.ofNullable(tokenSupplier).map(Supplier::get).ifPresent(accessToken ->
-            headerParams.add(HttpHeaders.AUTHORIZATION, "Bearer " + accessToken);
+            headerParams.add(HttpHeaders.AUTHORIZATION, "Bearer " + accessToken)
-        }
+        );
     }
 }

modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java

@@ -2963,7 +2963,7 @@ public class JavaClientCodegenTest {
 
 
     @Test
-    public void shouldGenerateOAuthTokenSuppliers() {
+    public void testRestTemplateWithGeneratedOAuthTokenSuppliers() {
 
         final Map<String, File> files = generateFromContract(
             "src/test/resources/3_0/java/oauth.yaml",
@@ -2994,6 +2994,27 @@ public class JavaClientCodegenTest {
 
     }
 
+    @Test
+    public void testRestClientWithGeneratedOAuthTokenSuppliers() {
+        final Map<String, File> files = generateFromContract(
+            "src/test/resources/3_0/java/oauth.yaml",
+            JavaClientCodegen.RESTCLIENT
+        );
+
+        final JavaFileAssert oAuth = JavaFileAssert.assertThat(files.get("OAuth.java"))
+            .printFileContent();
+        oAuth
+            .assertMethod("setAccessToken", "String")
+            .bodyContainsLines("setAccessToken(() -> accessToken);");
+        oAuth
+            .assertMethod("setAccessToken", "Supplier<String>")
+            .bodyContainsLines("this.tokenSupplier = tokenSupplier;");
+        oAuth
+            .assertMethod("applyToParams")
+            .bodyContainsLines("Optional.ofNullable(tokenSupplier).map(Supplier::get).ifPresent(accessToken ->")
+            .bodyContainsLines("headerParams.add(HttpHeaders.AUTHORIZATION, \"Bearer \" + accessToken)");
+    }
+    
     @Test public void testRestClientWithXML_issue_19137() {
         final Path output = newTempFolder();
         final CodegenConfigurator configurator = new CodegenConfigurator()

samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/auth/OAuth.java

@@ -13,25 +13,49 @@
 
 package org.openapitools.client.auth;
 
+import java.util.Optional;
+import java.util.function.Supplier;
 import org.springframework.http.HttpHeaders;
 import org.springframework.util.MultiValueMap;
 
+/**
+ * Provides support for RFC 6750 - Bearer Token usage for OAUTH 2.0 Authorization.
+ */
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.10.0-SNAPSHOT")
 public class OAuth implements Authentication {
-    private String accessToken;
+    private Supplier<String> tokenSupplier;
 
+    /**
+     * Returns the bearer token used for Authorization.
+     *
+     * @return The bearer token
+     */
     public String getAccessToken() {
-        return accessToken;
+        return tokenSupplier.get();
     }
 
+    /**
+     * Sets the bearer access token used for Authorization.
+     *
+     * @param accessToken The bearer token to send in the Authorization header
+     */
     public void setAccessToken(String accessToken) {
-        this.accessToken = accessToken;
+        setAccessToken(() -> accessToken);
+    }
+
+    /**
+     * Sets the supplier of bearer tokens used for Authorization.
+     *
+     * @param tokenSupplier The supplier of bearer tokens to send in the Authorization header
+     */
+    public void setAccessToken(Supplier<String> tokenSupplier) {
+        this.tokenSupplier = tokenSupplier;
     }
 
     @Override
     public void applyToParams(MultiValueMap<String, String> queryParams, HttpHeaders headerParams, MultiValueMap<String, String> cookieParams) {
-        if (accessToken != null) {
+        Optional.ofNullable(tokenSupplier).map(Supplier::get).ifPresent(accessToken ->
-            headerParams.add(HttpHeaders.AUTHORIZATION, "Bearer " + accessToken);
+            headerParams.add(HttpHeaders.AUTHORIZATION, "Bearer " + accessToken)
-        }
+        );
     }
 }

samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/auth/OAuth.java

@@ -13,25 +13,49 @@
 
 package org.openapitools.client.auth;
 
+import java.util.Optional;
+import java.util.function.Supplier;
 import org.springframework.http.HttpHeaders;
 import org.springframework.util.MultiValueMap;
 
+/**
+ * Provides support for RFC 6750 - Bearer Token usage for OAUTH 2.0 Authorization.
+ */
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.10.0-SNAPSHOT")
 public class OAuth implements Authentication {
-    private String accessToken;
+    private Supplier<String> tokenSupplier;
 
+    /**
+     * Returns the bearer token used for Authorization.
+     *
+     * @return The bearer token
+     */
     public String getAccessToken() {
-        return accessToken;
+        return tokenSupplier.get();
     }
 
+    /**
+     * Sets the bearer access token used for Authorization.
+     *
+     * @param accessToken The bearer token to send in the Authorization header
+     */
     public void setAccessToken(String accessToken) {
-        this.accessToken = accessToken;
+        setAccessToken(() -> accessToken);
+    }
+
+    /**
+     * Sets the supplier of bearer tokens used for Authorization.
+     *
+     * @param tokenSupplier The supplier of bearer tokens to send in the Authorization header
+     */
+    public void setAccessToken(Supplier<String> tokenSupplier) {
+        this.tokenSupplier = tokenSupplier;
     }
 
     @Override
     public void applyToParams(MultiValueMap<String, String> queryParams, HttpHeaders headerParams, MultiValueMap<String, String> cookieParams) {
-        if (accessToken != null) {
+        Optional.ofNullable(tokenSupplier).map(Supplier::get).ifPresent(accessToken ->
-            headerParams.add(HttpHeaders.AUTHORIZATION, "Bearer " + accessToken);
+            headerParams.add(HttpHeaders.AUTHORIZATION, "Bearer " + accessToken)
-        }
+        );
     }
 }

samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/auth/OAuth.java

@@ -13,25 +13,49 @@
 
 package org.openapitools.client.auth;
 
+import java.util.Optional;
+import java.util.function.Supplier;
 import org.springframework.http.HttpHeaders;
 import org.springframework.util.MultiValueMap;
 
+/**
+ * Provides support for RFC 6750 - Bearer Token usage for OAUTH 2.0 Authorization.
+ */
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.10.0-SNAPSHOT")
 public class OAuth implements Authentication {
-    private String accessToken;
+    private Supplier<String> tokenSupplier;
 
+    /**
+     * Returns the bearer token used for Authorization.
+     *
+     * @return The bearer token
+     */
     public String getAccessToken() {
-        return accessToken;
+        return tokenSupplier.get();
     }
 
+    /**
+     * Sets the bearer access token used for Authorization.
+     *
+     * @param accessToken The bearer token to send in the Authorization header
+     */
     public void setAccessToken(String accessToken) {
-        this.accessToken = accessToken;
+        setAccessToken(() -> accessToken);
+    }
+
+    /**
+     * Sets the supplier of bearer tokens used for Authorization.
+     *
+     * @param tokenSupplier The supplier of bearer tokens to send in the Authorization header
+     */
+    public void setAccessToken(Supplier<String> tokenSupplier) {
+        this.tokenSupplier = tokenSupplier;
     }
 
     @Override
     public void applyToParams(MultiValueMap<String, String> queryParams, HttpHeaders headerParams, MultiValueMap<String, String> cookieParams) {
-        if (accessToken != null) {
+        Optional.ofNullable(tokenSupplier).map(Supplier::get).ifPresent(accessToken ->
-            headerParams.add(HttpHeaders.AUTHORIZATION, "Bearer " + accessToken);
+            headerParams.add(HttpHeaders.AUTHORIZATION, "Bearer " + accessToken)
-        }
+        );
     }
 }