fix(spring): avoid duplicate Tag import when a model is named Tag

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

@@ -977,6 +977,16 @@ public void preprocessOpenAPI(OpenAPI openAPI) {
 
     @Override
     public OperationsMap postProcessOperationsWithModels(OperationsMap objs, List<ModelMap> allModels) {
+        // A model named `Tag` collides with io.swagger.v3.oas.annotations.tags.Tag. When this file
+        // imports the model, importing the annotation too is a duplicate single-type-import, which
+        // javac rejects outright. Reference the annotation by its fully qualified name instead and
+        // skip its import -- only for the files that actually hit the clash.
+        final String tagModelImport = modelPackage() + ".Tag";
+        if (objs.getImports() != null
+                && objs.getImports().stream().anyMatch(imp -> tagModelImport.equals(imp.get("import")))) {
+            objs.put("qualifySwaggerTagAnnotation", true);
+        }
+
         final OperationMap operations = objs.getOperations();
         if (operations != null) {
             final List<CodegenOperation> ops = operations.getOperation();

modules/openapi-generator/src/main/resources/JavaSpring/api.mustache

@@ -17,7 +17,9 @@ import io.swagger.v3.oas.annotations.media.Content;
 import io.swagger.v3.oas.annotations.media.Schema;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
 import io.swagger.v3.oas.annotations.security.SecurityRequirement;
+{{^qualifySwaggerTagAnnotation}}
 import io.swagger.v3.oas.annotations.tags.Tag;
+{{/qualifySwaggerTagAnnotation}}
 import io.swagger.v3.oas.annotations.enums.ParameterIn;
 import io.swagger.v3.oas.annotations.media.ExampleObject;
 {{/swagger2AnnotationLibrary}}
@@ -106,7 +108,7 @@ import {{javaxPackage}}.annotation.Generated;
 {{/useResponseEntity}}
 {{/useSpringController}}
 {{#swagger2AnnotationLibrary}}
-@Tag(name = "{{{tagName}}}", description = {{#tagDescription}}"{{{.}}}"{{/tagDescription}}{{^tagDescription}}"the {{{tagName}}} API"{{/tagDescription}})
+{{#qualifySwaggerTagAnnotation}}@io.swagger.v3.oas.annotations.tags.Tag{{/qualifySwaggerTagAnnotation}}{{^qualifySwaggerTagAnnotation}}@Tag{{/qualifySwaggerTagAnnotation}}(name = "{{{tagName}}}", description = {{#tagDescription}}"{{{.}}}"{{/tagDescription}}{{^tagDescription}}"the {{{tagName}}} API"{{/tagDescription}})
 {{/swagger2AnnotationLibrary}}
 {{#swagger1AnnotationLibrary}}
 @Api(value = "{{{tagName}}}", description = {{#tagDescription}}"{{{.}}}"{{/tagDescription}}{{^tagDescription}}"the {{{tagName}}} API"{{/tagDescription}})

modules/openapi-generator/src/main/resources/JavaSpring/apiController.mustache

@@ -11,7 +11,9 @@ import io.swagger.v3.oas.annotations.media.Content;
 import io.swagger.v3.oas.annotations.media.Schema;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
 import io.swagger.v3.oas.annotations.security.SecurityRequirement;
+{{^qualifySwaggerTagAnnotation}}
 import io.swagger.v3.oas.annotations.tags.Tag;
+{{/qualifySwaggerTagAnnotation}}
 {{/swagger2AnnotationLibrary}}
 {{#swagger1AnnotationLibrary}}
 import io.swagger.annotations.*;

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

@@ -1206,6 +1206,35 @@ public void shouldGenerateExclusiveMinMaxForOAS31() throws IOException {
     }
 
 
+    @Test
+    public void modelNamedTagDoesNotClashWithSwaggerTagAnnotation() throws IOException {
+        // A model named `Tag` collides with io.swagger.v3.oas.annotations.tags.Tag. Importing both
+        // is a duplicate single-type-import, which javac rejects outright, so the generated api
+        // must fall back to the fully qualified annotation name and skip the import.
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+
+        OpenAPI openAPI = new OpenAPIParser()
+                .readLocation("src/test/resources/3_0/spring/model-named-tag.yaml", null, new ParseOptions())
+                .getOpenAPI();
+        SpringCodegen codegen = new SpringCodegen();
+        codegen.setOutputDir(output.getAbsolutePath());
+        codegen.additionalProperties().put(INTERFACE_ONLY, "true");
+
+        ClientOptInput input = new ClientOptInput().openAPI(openAPI).config(codegen);
+        DefaultGenerator generator = new DefaultGenerator();
+        generator.setGenerateMetadata(false);
+
+        Map<String, File> files = generator.opts(input).generate().stream()
+                .collect(Collectors.toMap(File::getName, Function.identity()));
+
+        Path api = files.get("TagApi.java").toPath();
+        assertFileNotContains(api, "import io.swagger.v3.oas.annotations.tags.Tag;");
+        assertFileContains(api, "@io.swagger.v3.oas.annotations.tags.Tag(name = \"pets\"");
+        // the model import must still be there -- that is the type actually used in signatures
+        assertFileContains(api, "import org.openapitools.model.Tag;");
+    }
+
     @Test
     public void shouldUseTagsForClassname() throws IOException {
         File output = Files.createTempDirectory("test").toFile().getCanonicalFile();

modules/openapi-generator/src/test/resources/3_0/spring/model-named-tag.yaml

@@ -0,0 +1,25 @@
+openapi: 3.0.3
+info:
+  title: model named Tag
+  version: 1.0.0
+tags:
+  - name: pets
+paths:
+  /tag:
+    get:
+      tags:
+        - pets
+      operationId: getTag
+      responses:
+        "200":
+          description: ok
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Tag"
+components:
+  schemas:
+    Tag:
+      properties:
+        id:
+          type: string