kotlin-server: Add support for Javalin

.github/workflows/samples-kotlin-server-jdk17.yaml

@@ -4,11 +4,13 @@ on:
   push:
     branches:
       - 'samples/server/petstore/kotlin-springboot-3*/**'
+      - 'samples/server/petstore/kotlin-server/javalin/**'
       # comment out due to gradle build failure
       # - samples/server/petstore/kotlin-spring-default/**
   pull_request:
     paths:
       - 'samples/server/petstore/kotlin-springboot-3*/**'
+      - 'samples/server/petstore/kotlin-server/javalin/**'
       # comment out due to gradle build failure
       # - samples/server/petstore/kotlin-spring-default/**
 
@@ -26,6 +28,7 @@ jobs:
           # server
           - samples/server/petstore/kotlin-springboot-3
           - samples/server/petstore/kotlin-springboot-request
+          - samples/server/petstore/kotlin-server/javalin
           # comment out due to gradle build failure
           # - samples/server/petstore/kotlin-spring-default/
     steps:

.github/workflows/samples-kotlin-server.yaml

@@ -37,6 +37,7 @@ jobs:
           - samples/server/petstore/kotlin-server/jaxrs-spec
           - samples/server/petstore/kotlin-server/jaxrs-spec-mutiny
           - samples/server/petstore/kotlin-server-modelMutable
+          - samples/server/petstore/kotlin-server/javalin
           - samples/server/others/kotlin-server/jaxrs-spec
           # comment out due to gradle build failure
           #- samples/server/petstore/kotlin-spring-default

bin/configs/kotlin-server-javalin.yaml

@@ -0,0 +1,7 @@
+generatorName: kotlin-server
+outputDir: samples/server/petstore/kotlin-server/javalin
+library: javalin5
+inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore.yaml
+templateDir: modules/openapi-generator/src/main/resources/kotlin-server
+additionalProperties:
+  hideGenerationTimestamp: "true"

docs/generators/kotlin-server.md

@@ -32,7 +32,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |featureResources|Generates routes in a typed way, for both: constructing URLs and reading the parameters.| |true|
 |groupId|Generated artifact package's organization (i.e. maven groupId).| |org.openapitools|
 |interfaceOnly|Whether to generate only API interface stubs without the server files. This option is currently supported only when using jaxrs-spec library.| |false|
-|library|library template (sub-template)|<dl><dt>**ktor**</dt><dd>ktor framework</dd><dt>**jaxrs-spec**</dt><dd>JAX-RS spec only</dd></dl>|ktor|
+|library|library template (sub-template)|<dl><dt>**ktor**</dt><dd>ktor framework</dd><dt>**jaxrs-spec**</dt><dd>JAX-RS spec only</dd><dt>**javalin5**</dt><dd>Javalin 5</dd></dl>|ktor|
 |modelMutable|Create mutable models| |false|
 |omitGradleWrapper|Whether to omit Gradle wrapper for creating a sub project.| |false|
 |packageName|Generated artifact package name.| |org.openapitools.server|

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

@@ -1143,4 +1143,44 @@ protected ImmutableMap.Builder<String, Mustache.Lambda> addMustacheLambdas() {
         return super.addMustacheLambdas()
                 .put("escapeDollar", new EscapeChar("(?<!\\\\)\\$", "\\\\\\$"));
     }
+
+    protected interface DataTypeAssigner {
+        void setReturnType(String returnType);
+
+        void setReturnContainer(String returnContainer);
+    }
+
+    /**
+     * @param returnType       The return type that needs to be converted
+     * @param dataTypeAssigner An object that will assign the data to the respective fields in the model.
+     */
+    protected void doDataTypeAssignment(final String returnType, DataTypeAssigner dataTypeAssigner) {
+        if (returnType == null) {
+            dataTypeAssigner.setReturnType("Unit");
+        } else if (returnType.startsWith("kotlin.collections.List")) {
+            int end = returnType.lastIndexOf(">");
+            if (end > 0) {
+                dataTypeAssigner.setReturnType(returnType.substring("kotlin.collections.List<".length(), end).trim());
+                dataTypeAssigner.setReturnContainer("List");
+            }
+        } else if (returnType.startsWith("kotlin.collections.MutableList")) {
+            int end = returnType.lastIndexOf(">");
+            if (end > 0) {
+                dataTypeAssigner.setReturnType(returnType.substring("kotlin.collections.MutableList<".length(), end).trim());
+                dataTypeAssigner.setReturnContainer("List");
+            }
+        } else if (returnType.startsWith("kotlin.collections.Map")) {
+            int end = returnType.lastIndexOf(">");
+            if (end > 0) {
+                dataTypeAssigner.setReturnType(returnType.substring("kotlin.collections.Map<".length(), end).split(",")[1].trim());
+                dataTypeAssigner.setReturnContainer("Map");
+            }
+        } else if (returnType.startsWith("kotlin.collections.MutableMap")) {
+            int end = returnType.lastIndexOf(">");
+            if (end > 0) {
+                dataTypeAssigner.setReturnType(returnType.substring("kotlin.collections.MutableMap<".length(), end).split(",")[1].trim());
+                dataTypeAssigner.setReturnContainer("Map");
+            }
+        }
+    }
 }

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

@@ -19,11 +19,13 @@
 
 import com.google.common.collect.ImmutableMap;
 import org.apache.commons.lang3.StringUtils;
-import org.openapitools.codegen.CodegenConstants;
-import org.openapitools.codegen.CodegenType;
-import org.openapitools.codegen.SupportingFile;
+import org.openapitools.codegen.*;
 import org.openapitools.codegen.languages.features.BeanValidationFeatures;
 import org.openapitools.codegen.meta.features.*;
+import org.openapitools.codegen.model.ModelMap;
+import org.openapitools.codegen.model.OperationMap;
+import org.openapitools.codegen.model.OperationsMap;
+import org.openapitools.codegen.templating.mustache.LowercaseLambda;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -119,6 +121,7 @@ public KotlinServerCodegen() {
 
         supportedLibraries.put(Constants.KTOR, "ktor framework");
         supportedLibraries.put(Constants.JAXRS_SPEC, "JAX-RS spec only");
+        supportedLibraries.put(Constants.JAVALIN5, "Javalin 5");
 
         // TODO: Configurable server engine. Defaults to netty in build.gradle.
         addOption(CodegenConstants.LIBRARY, CodegenConstants.LIBRARY_DESC, DEFAULT_LIBRARY, supportedLibraries);
@@ -322,7 +325,13 @@ public void processOpts() {
             supportingFiles.add(new SupportingFile("Dockerfile.mustache", "", "Dockerfile"));
         }
 
-        supportingFiles.add(new SupportingFile("build.gradle.mustache", "", "build.gradle"));
+        String gradleBuildFile = "build.gradle";
+
+        if (library.equals(Constants.JAVALIN5)) {
+            gradleBuildFile = "build.gradle.kts";
+        }
+
+        supportingFiles.add(new SupportingFile(gradleBuildFile + ".mustache", "", gradleBuildFile));
         supportingFiles.add(new SupportingFile("settings.gradle.mustache", "", "settings.gradle"));
         supportingFiles.add(new SupportingFile("gradle.properties", "", "gradle.properties"));
 
@@ -340,6 +349,13 @@ public void processOpts() {
             final String infrastructureFolder = (sourceFolder + File.separator + packageName + File.separator + "infrastructure").replace(".", File.separator);
 
             supportingFiles.add(new SupportingFile("ApiKeyAuth.kt.mustache", infrastructureFolder, "ApiKeyAuth.kt"));
+        } else if (library.equals(Constants.JAVALIN5)) {
+            supportingFiles.add(new SupportingFile("Main.kt.mustache", packageFolder, "Main.kt"));
+            apiTemplateFiles.put("service.mustache", "Service.kt");
+            apiTemplateFiles.put("serviceImpl.mustache", "ServiceImpl.kt");
+            additionalProperties.put("lowercase", new LowercaseLambda());
+            typeMapping.put("file", "io.javalin.http.UploadedFile");
+            importMapping.put("io.javalin.http.UploadedFile", "io.javalin.http.UploadedFile");
         }
     }
 
@@ -351,6 +367,8 @@ public void setUseBeanValidation(boolean useBeanValidation) {
     public static class Constants {
         public final static String KTOR = "ktor";
         public final static String JAXRS_SPEC = "jaxrs-spec";
+
+        public final static String JAVALIN5 = "javalin5";
         public final static String AUTOMATIC_HEAD_REQUESTS = "featureAutoHead";
         public final static String AUTOMATIC_HEAD_REQUESTS_DESC = "Automatically provide responses to HEAD requests for existing routes that have the GET verb defined.";
         public final static String CONDITIONAL_HEADERS = "featureConditionalHeaders";
@@ -390,4 +408,50 @@ public void postProcess() {
         System.out.println("# Please support his work directly via https://patreon.com/jimschubert \uD83D\uDE4F     #");
         System.out.println("################################################################################");
     }
+
+    @Override
+    public OperationsMap postProcessOperationsWithModels(OperationsMap objs, List<ModelMap> allModels) {
+        OperationMap operations = objs.getOperations();
+        if (operations != null) {
+            List<CodegenOperation> ops = operations.getOperation();
+            ops.forEach(operation -> {
+                List<CodegenResponse> responses = operation.responses;
+                if (responses != null) {
+                    responses.forEach(resp -> {
+
+                        if ("0".equals(resp.code)) {
+                            resp.code = "200";
+                        }
+
+                        doDataTypeAssignment(resp.dataType, new DataTypeAssigner() {
+                            @Override
+                            public void setReturnType(final String returnType) {
+                                resp.dataType = returnType;
+                            }
+
+                            @Override
+                            public void setReturnContainer(final String returnContainer) {
+                                resp.containerType = returnContainer;
+                            }
+                        });
+                    });
+                }
+
+                doDataTypeAssignment(operation.returnType, new DataTypeAssigner() {
+
+                    @Override
+                    public void setReturnType(final String returnType) {
+                        operation.returnType = returnType;
+                    }
+
+                    @Override
+                    public void setReturnContainer(final String returnContainer) {
+                        operation.returnContainer = returnContainer;
+                    }
+                });
+            });
+        }
+
+        return objs;
+    }
 }

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

@@ -949,46 +949,6 @@ private String getNonMutableContainerTypeIfNeeded(String type) {
         return type;
     }
 
-    private interface DataTypeAssigner {
-        void setReturnType(String returnType);
-
-        void setReturnContainer(String returnContainer);
-    }
-
-    /**
-     * @param returnType       The return type that needs to be converted
-     * @param dataTypeAssigner An object that will assign the data to the respective fields in the model.
-     */
-    private void doDataTypeAssignment(final String returnType, DataTypeAssigner dataTypeAssigner) {
-        if (returnType == null) {
-            dataTypeAssigner.setReturnType("Unit");
-        } else if (returnType.startsWith("kotlin.collections.List")) {
-            int end = returnType.lastIndexOf(">");
-            if (end > 0) {
-                dataTypeAssigner.setReturnType(returnType.substring("kotlin.collections.List<".length(), end).trim());
-                dataTypeAssigner.setReturnContainer("List");
-            }
-        } else if (returnType.startsWith("kotlin.collections.MutableList")) {
-            int end = returnType.lastIndexOf(">");
-            if (end > 0) {
-                dataTypeAssigner.setReturnType(returnType.substring("kotlin.collections.MutableList<".length(), end).trim());
-                dataTypeAssigner.setReturnContainer("List");
-            }
-        } else if (returnType.startsWith("kotlin.collections.Map")) {
-            int end = returnType.lastIndexOf(">");
-            if (end > 0) {
-                dataTypeAssigner.setReturnType(returnType.substring("kotlin.collections.Map<".length(), end).split(",")[1].trim());
-                dataTypeAssigner.setReturnContainer("Map");
-            }
-        } else if (returnType.startsWith("kotlin.collections.MutableMap")) {
-            int end = returnType.lastIndexOf(">");
-            if (end > 0) {
-                dataTypeAssigner.setReturnType(returnType.substring("kotlin.collections.MutableMap<".length(), end).split(",")[1].trim());
-                dataTypeAssigner.setReturnContainer("Map");
-            }
-        }
-    }
-
     private static String sanitizeDirectory(String in) {
         return in.replace(".", File.separator);
     }

modules/openapi-generator/src/main/resources/kotlin-server/libraries/javalin5/Main.kt.mustache

@@ -0,0 +1,36 @@
+package {{packageName}}
+
+import io.javalin.Javalin
+import io.javalin.community.routing.dsl.routing
+
+{{#apiInfo}}
+{{#apis}}
+{{#operations}}import {{apiPackage}}.{{classname}}
+import {{apiPackage}}.{{classname}}ServiceImpl
+{{/operations}}
+{{/apis}}
+
+fun main() {
+    {{#apis}}
+    {{#operations}}
+    val {{classname}} = {{classname}}({{classname}}ServiceImpl())
+    {{/operations}}
+    {{/apis}}
+
+    val app = Javalin
+        .create { config ->
+            config.routing {
+                {{#apis}}
+                {{#operations}}
+                {{#operation}}
+                {{#lowercase}}{{httpMethod}}{{/lowercase}}("{{path}}", {{classname}}::{{operationId}})
+                {{/operation}}
+                {{/operations}}
+
+                {{/apis}}
+            }
+        }
+
+    app.start({{serverPort}})
+}
+{{/apiInfo}}

modules/openapi-generator/src/main/resources/kotlin-server/libraries/javalin5/README.mustache

@@ -0,0 +1,94 @@
+# {{packageName}} - Kotlin Server library for {{appName}}
+
+{{#unescapedAppDescription}}
+{{.}}
+{{/unescapedAppDescription}}
+
+Generated by OpenAPI Generator {{generatorVersion}}{{^hideGenerationTimestamp}} ({{generatedDate}}){{/hideGenerationTimestamp}}.
+
+## Build
+
+First, create the gradle wrapper script:
+
+```
+gradle wrapper
+```
+
+Then, run:
+
+```
+./gradlew check assemble
+```
+
+This runs all tests and packages the library.
+
+## Running
+
+The server builds as a fat jar with a main entrypoint. To start the service, run `java -jar ./build/libs/{{artifactId}}.jar`.
+
+You may also run in docker:
+
+```
+docker build -t {{artifactId}} .
+docker run -p 8080:8080 {{artifactId}}
+```
+
+## Features/Implementation Notes
+
+* Supports JSON inputs/outputs, File inputs, and Form inputs (see ktor documentation for more info).
+* ~Supports collection formats for query parameters: csv, tsv, ssv, pipes.~
+* Some Kotlin and Java types are fully qualified to avoid conflicts with types defined in OpenAPI definitions.
+
+{{#generateApiDocs}}
+<a id="documentation-for-api-endpoints"></a>
+## Documentation for API Endpoints
+
+All URIs are relative to *{{{basePath}}}*
+
+Class | Method | HTTP request | Description
+------------ | ------------- | ------------- | -------------
+{{#apiInfo}}{{#apis}}{{#operations}}{{#operation}}*{{classname}}* | [**{{operationId}}**]({{apiDocPath}}{{classname}}.md#{{operationIdLowerCase}}) | **{{httpMethod}}** {{path}} | {{{summary}}}
+{{/operation}}{{/operations}}{{/apis}}{{/apiInfo}}
+{{/generateApiDocs}}
+
+{{#generateModelDocs}}
+<a id="documentation-for-models"></a>
+## Documentation for Models
+
+{{#modelPackage}}
+{{#models}}{{#model}} - [{{{modelPackage}}}.{{{classname}}}]({{modelDocPath}}{{{classname}}}.md)
+{{/model}}{{/models}}
+{{/modelPackage}}
+{{^modelPackage}}
+No model defined in this package
+{{/modelPackage}}
+{{/generateModelDocs}}
+
+<a id="documentation-for-authorization"></a>
+## Documentation for Authorization
+
+{{^authMethods}}Endpoints do not require authorization.{{/authMethods}}
+{{#hasAuthMethods}}Authentication schemes defined for the API:{{/hasAuthMethods}}
+{{#authMethods}}
+<a id="{{name}}"></a>
+### {{name}}
+
+{{#isApiKey}}- **Type**: API key
+- **API key parameter name**: {{keyParamName}}
+- **Location**: {{#isKeyInQuery}}URL query string{{/isKeyInQuery}}{{#isKeyInHeader}}HTTP header{{/isKeyInHeader}}
+{{/isApiKey}}
+{{#isBasicBasic}}- **Type**: HTTP basic authentication
+{{/isBasicBasic}}
+{{#isBasicBearer}}- **Type**: HTTP Bearer Token authentication{{#bearerFormat}} ({{{.}}}){{/bearerFormat}}
+{{/isBasicBearer}}
+{{#isHttpSignature}}- **Type**: HTTP signature authentication
+{{/isHttpSignature}}
+{{#isOAuth}}- **Type**: OAuth
+- **Flow**: {{flow}}
+- **Authorization URL**: {{authorizationUrl}}
+- **Scopes**: {{^scopes}}N/A{{/scopes}}
+{{#scopes}}  - {{scope}}: {{description}}
+{{/scopes}}
+{{/isOAuth}}
+
+{{/authMethods}}