fixes imports when spec contains no schema

Author: frantuma

modules/swagger-codegen/src/main/java/io/swagger/codegen/v3/DefaultGenerator.java

@@ -416,6 +416,11 @@ private void generateApis(List<File> files, List<Object> allOperations, List<Obj
         if (!generateApis) {
             return;
         }
+        boolean hasModel = true;
+        if (allModels == null || allModels.isEmpty()) {
+            hasModel = false;
+        }
+
         Map<String, List<CodegenOperation>> paths = processPaths(this.openAPI.getPaths());
         Set<String> apisToGenerate = null;
         String apiNames = System.getProperty("apis");
@@ -464,6 +469,9 @@ public int compare(CodegenOperation one, CodegenOperation another) {
                 }
                 operation.put("sortParamsByRequiredFlag", sortParamsByRequiredFlag);
 
+                operation.put("hasModel", hasModel);
+
+
                 allOperations.add(new HashMap<>(operation));
                 for (int i = 0; i < allOperations.size(); i++) {
                     Map<String, Object> oo = (Map<String, Object>) allOperations.get(i);

modules/swagger-codegen/src/test/java/io/swagger/codegen/v3/service/GeneratorServiceTest.java

@@ -6,6 +6,7 @@
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.parser.OpenAPIV3Parser;
 import io.swagger.v3.parser.core.models.ParseOptions;
+import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.IOUtils;
 import org.testng.Assert;
 import org.testng.annotations.Test;
@@ -33,6 +34,34 @@ public void testGeneratorServiceJava3() {
         Assert.assertFalse(files.isEmpty());
     }
 
+    @Test
+    public void testNoModel() throws Exception{
+
+        String path = getTmpFolder().getAbsolutePath();
+        GenerationRequest request = new GenerationRequest();
+        request
+                .codegenVersion(GenerationRequest.CodegenVersion.V3)
+                .type(GenerationRequest.Type.SERVER)
+                .lang("jaxrs-jersey")
+                .spec(loadSpecAsNode("3_0_0/noModel.yaml", true, false))
+                .options(
+                        new Options()
+                                .outputDir(path)
+                );
+        List<File> files = new GeneratorService().generationRequest(request).generate();
+        System.out.println(path);
+        Assert.assertFalse(files.isEmpty());
+        for (File f: files) {
+            String relPath = f.getAbsolutePath().substring(path.length());
+            if ("/src/main/java/io/swagger/api/impl/FooApiServiceImpl.java".equals(relPath) ||
+                    "/src/gen/java/io/swagger/api/FooApiService.java".equals(relPath) ||
+                    "/src/gen/java/io/swagger/api/FooApi.java".equals(relPath)) {
+                Assert.assertFalse(FileUtils.readFileToString(f).contains("import io.swagger.model"));
+            }
+        }
+
+    }
+
     @Test(description = "test generator service with java 2.0")
     public void testGeneratorServiceJava2() {
 

modules/swagger-codegen/src/test/resources/3_0_0/noModel.yaml

@@ -0,0 +1,16 @@
+openapi: 3.0.0
+info:
+  title: Sample API
+  version: '1'
+servers:
+  - url: 'http://localhost:9080/1'
+paths:
+  /foo:
+    get:
+      responses:
+        '200':
+          description: OK
+          content:
+            application/json:
+              schema:
+                type: object