spring: fix spring pageable used without any config (#15113) (fix #13052)

* spring: fix spring pageable used without any config

Spring Pageable is imported whenever we have an API with
a Pageable Json schema, even if x-spring-paginated is not
set.

This commit imports Spring Pageable only if
x-spring-paginated is set to true.

* spring: add unit test for pageable fix

* spring: fix spring pageable feedback from review

remove unrelated example

---------

Co-authored-by: gonzalad <gonzalad@users.noreply.github.com>

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/SpringCodegen.java

@@ -530,7 +530,6 @@ public class SpringCodegen extends AbstractJavaCodegen
 
         typeMapping.put("file", "org.springframework.core.io.Resource");
         importMapping.put("org.springframework.core.io.Resource", "org.springframework.core.io.Resource");
-        importMapping.put("Pageable", "org.springframework.data.domain.Pageable");
         importMapping.put("DateTimeFormat", "org.springframework.format.annotation.DateTimeFormat");
         importMapping.put("ApiIgnore", "springfox.documentation.annotations.ApiIgnore");
         importMapping.put("ParameterObject", "org.springdoc.api.annotations.ParameterObject");
@@ -1191,6 +1190,13 @@ public class SpringCodegen extends AbstractJavaCodegen
      */
     @Override
     public CodegenOperation fromOperation(String path, String httpMethod, Operation operation, List<Server> servers) {
+
+        // add Pageable import only if x-spring-paginated explicitly used
+        // this allows to use a custom Pageable schema without importing Spring Pageable.
+        if (Boolean.TRUE.equals(operation.getExtensions().get("x-spring-paginated"))) {
+            importMapping.put("Pageable", "org.springframework.data.domain.Pageable");
+        }
+
         CodegenOperation codegenOperation = super.fromOperation(path, httpMethod, operation, servers);
 
         // add org.springframework.format.annotation.DateTimeFormat when needed

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

@@ -1385,7 +1385,6 @@ public class SpringCodegenTest {
         final SpringCodegen codegen = new SpringCodegen();
         codegen.processOpts();
         Assert.assertEquals(codegen.importMapping().get("org.springframework.core.io.Resource"), "org.springframework.core.io.Resource");
-        Assert.assertEquals(codegen.importMapping().get("Pageable"), "org.springframework.data.domain.Pageable");
         Assert.assertEquals(codegen.importMapping().get("DateTimeFormat"), "org.springframework.format.annotation.DateTimeFormat");
         Assert.assertEquals(codegen.importMapping().get("ApiIgnore"), "springfox.documentation.annotations.ApiIgnore");
         Assert.assertEquals(codegen.importMapping().get("ParameterObject"), "org.springdoc.api.annotations.ParameterObject");
@@ -1781,13 +1780,31 @@ public class SpringCodegenTest {
         files = generateFromContract("src/test/resources/2_0/petstore-with-spring-pageable.yaml", SPRING_BOOT, additionalProperties);
 
         JavaFileAssert.assertThat(files.get("PetApi.java"))
-            .hasImports("org.springdoc.core.annotations.ParameterObject")
+            .hasImports("org.springdoc.core.annotations.ParameterObject", "org.springframework.data.domain.Pageable")
             .assertMethod("findPetsByStatus")
             .hasParameter("pageable").withType("Pageable")
             .assertParameterAnnotations()
             .containsWithName("ParameterObject");
     }
 
+    @Test
+    public void paramPageableIsNotSpringPaginated_issue13052() throws Exception {
+        Map<String, Object> additionalProperties = new HashMap<>();
+        additionalProperties.put(SpringCodegen.USE_TAGS, "true");
+        additionalProperties.put(DOCUMENTATION_PROVIDER, "springdoc");
+        additionalProperties.put(SpringCodegen.INTERFACE_ONLY, "true");
+        additionalProperties.put(SpringCodegen.SKIP_DEFAULT_INTERFACE, "true");
+        additionalProperties.put(USE_SPRING_BOOT3, "true");
+
+        Map<String, File> files = generateFromContract("src/test/resources/bugs/issue_13052.yaml", SPRING_BOOT, additionalProperties);
+
+        JavaFileAssert.assertThat(files.get("PetApi.java"))
+                .hasImports("org.openapitools.model.Pageable")
+                .hasNoImports("org.springframework.data.domain.Pageable", "org.springdoc.core.annotations.ParameterObject")
+                .assertMethod("findPageable")
+                .hasParameter("pageable").withType("Pageable");
+    }
+
     @Test
     public void shouldSetDefaultValueForMultipleArrayItems() throws IOException {
         Map<String, Object> additionalProperties = new HashMap<>();

modules/openapi-generator/src/test/resources/bugs/issue_13052.yaml

@@ -0,0 +1,63 @@
+openapi: 3.0.1
+info:
+  title: OpenAPI Petstore
+  description: This is a sample server Petstore server. For this sample, you can use
+    the api key `special-key` to test the authorization filters.
+  license:
+    name: Apache-2.0
+    url: http://www.apache.org/licenses/LICENSE-2.0.html
+  version: 1.0.0
+servers:
+  - url: http://petstore.swagger.io/v2
+tags:
+  - name: pet
+    description: Everything about your Pets
+  - name: store
+    description: Access to Petstore orders
+  - name: user
+    description: Operations about user
+paths:
+  /pet/findPageable:
+    get:
+      tags:
+        - pet
+      summary: Finds Pets by status
+      description: Multiple status values can be provided with comma separated strings
+      operationId: findPageable
+      parameters:
+        - name: pageable
+          in: query
+          style: form
+          explode: true
+          schema:
+            $ref: "#/components/schemas/Pageable"
+      responses:
+        200:
+          description: successful operation
+          content:
+            application/xml:
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/Pet'
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/Pet'
+        400:
+          description: Invalid status value
+          content: {}
+
+
+components:
+  schemas:
+    Pageable:
+      type: object
+      properties:
+        page:
+          type: integer
+          description: page number
+        size:
+          type: integer
+          description: page size