[kotlin] implement serializable data classes (#8317)

Author: LucasKuhlemann

modules/openapi-generator/src/main/resources/kotlin-spring/dataClass.mustache

@@ -14,7 +14,7 @@
 {{/-last}}{{/requiredVars}}{{#hasRequired}}{{#hasOptional}},
 {{/hasOptional}}{{/hasRequired}}{{#optionalVars}}{{>dataClassOptVar}}{{^-last}},
 {{/-last}}{{/optionalVars}}
-) {{/discriminator}}{{#parent}}: {{{.}}}{{/parent}}{
+) {{/discriminator}}{{#parent}}: {{{.}}}{{#serializableModel}}, Serializable{{/serializableModel}}{{/parent}}{{#serializableModel}}: Serializable{{/serializableModel}}{
 {{#discriminator}}
     {{#requiredVars}}
         {{>interfaceReqVar}}
@@ -33,4 +33,9 @@
         @JsonProperty({{{value}}}) {{{name}}}({{{value}}}){{^-last}},{{/-last}}{{/enumVars}}{{/allowableValues}}
     }
 {{/isEnum}}{{/vars}}{{/hasEnums}}
+{{#serializableModel}}
+    companion object {
+        private const val serialVersionUID: kotlin.Long = 1
+    }
+{{/serializableModel}}
 }

modules/openapi-generator/src/main/resources/kotlin-spring/model.mustache

@@ -3,6 +3,9 @@ package {{package}}
 import java.util.Objects
 {{#imports}}import {{import}}
 {{/imports}}
+{{#serializableModel}}
+import java.io.Serializable
+{{/serializableModel}}
 {{#useBeanValidation}}
 import {{javaxPackage}}.validation.constraints.DecimalMax
 import {{javaxPackage}}.validation.constraints.DecimalMin

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

@@ -184,6 +184,7 @@ public void testSettersForConfigValues() throws Exception {
         codegen.setServiceImplementation(true);
         codegen.setUseBeanValidation(false);
         codegen.setReactive(false);
+        codegen.setSerializableModel(true);
         codegen.processOpts();
 
         Assert.assertEquals(codegen.modelPackage(), "xx.yyyyyyyy.model");
@@ -206,6 +207,8 @@ public void testSettersForConfigValues() throws Exception {
         Assert.assertEquals(codegen.additionalProperties().get(KotlinSpringServerCodegen.USE_BEANVALIDATION), false);
         Assert.assertFalse(codegen.isReactive());
         Assert.assertEquals(codegen.additionalProperties().get(KotlinSpringServerCodegen.REACTIVE), false);
+        Assert.assertTrue(codegen.isSerializableModel());
+        Assert.assertEquals(codegen.additionalProperties().get(CodegenConstants.SERIALIZABLE_MODEL), true);
     }
 
     @Test
@@ -747,4 +750,35 @@ public void givenMultipartForm_whenGenerateReactiveServer_thenParameterAreCreate
                            "@Parameter(description = \"image to upload\") @Valid @RequestPart(\"image\", required = false) image: org.springframework.core.io.Resource?");
 
     }
-}
+
+    @Test
+    public void generateSerializableModel() throws Exception {
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+        String outputPath = output.getAbsolutePath().replace('\\', '/');
+
+        KotlinSpringServerCodegen codegen = new KotlinSpringServerCodegen();
+        codegen.setOutputDir(output.getAbsolutePath());
+        codegen.additionalProperties().put(CodegenConstants.SERIALIZABLE_MODEL, true);
+
+        ClientOptInput input = new ClientOptInput()
+                .openAPI(TestUtils.parseSpec("src/test/resources/3_0/kotlin/petstore.yaml"))
+                .config(codegen);
+        DefaultGenerator generator = new DefaultGenerator();
+
+        generator.setGeneratorPropertyDefault(CodegenConstants.MODELS, "true");
+        generator.setGeneratorPropertyDefault(CodegenConstants.MODEL_TESTS, "false");
+        generator.setGeneratorPropertyDefault(CodegenConstants.MODEL_DOCS, "false");
+        generator.setGeneratorPropertyDefault(CodegenConstants.APIS, "false");
+        generator.setGeneratorPropertyDefault(CodegenConstants.SUPPORTING_FILES, "false");
+
+        generator.opts(input).generate();
+
+        assertFileContains(
+                Paths.get(outputPath + "/src/main/kotlin/org/openapitools/model/Pet.kt"),
+                "import java.io.Serializable",
+                ") : Serializable{",
+                "private const val serialVersionUID: kotlin.Long = 1"
+        );
+    }
+}

samples/server/petstore/kotlin-spring-cloud/src/main/kotlin/org/openapitools/model/Category.kt

@@ -2,6 +2,7 @@ package org.openapitools.model
 
 import java.util.Objects
 import com.fasterxml.jackson.annotation.JsonProperty
+import java.io.Serializable
 import javax.validation.constraints.DecimalMax
 import javax.validation.constraints.DecimalMin
 import javax.validation.constraints.Email
@@ -23,7 +24,10 @@ data class Category(
 
     @get:Pattern(regexp="^[a-zA-Z0-9]+[a-zA-Z0-9\\.\\-_]*[a-zA-Z0-9]+$")
     @get:JsonProperty("name") val name: kotlin.String? = null
-) {
+) : Serializable{
 
+    companion object {
+        private const val serialVersionUID: kotlin.Long = 1
+    }
 }
 

samples/server/petstore/kotlin-spring-cloud/src/main/kotlin/org/openapitools/model/ModelApiResponse.kt

@@ -2,6 +2,7 @@ package org.openapitools.model
 
 import java.util.Objects
 import com.fasterxml.jackson.annotation.JsonProperty
+import java.io.Serializable
 import javax.validation.constraints.DecimalMax
 import javax.validation.constraints.DecimalMin
 import javax.validation.constraints.Email
@@ -25,7 +26,10 @@ data class ModelApiResponse(
     @get:JsonProperty("type") val type: kotlin.String? = null,
 
     @get:JsonProperty("message") val message: kotlin.String? = null
-) {
+) : Serializable{
 
+    companion object {
+        private const val serialVersionUID: kotlin.Long = 1
+    }
 }
 

samples/server/petstore/kotlin-spring-cloud/src/main/kotlin/org/openapitools/model/Order.kt

@@ -3,6 +3,7 @@ package org.openapitools.model
 import java.util.Objects
 import com.fasterxml.jackson.annotation.JsonProperty
 import com.fasterxml.jackson.annotation.JsonValue
+import java.io.Serializable
 import javax.validation.constraints.DecimalMax
 import javax.validation.constraints.DecimalMin
 import javax.validation.constraints.Email
@@ -35,7 +36,7 @@ data class Order(
     @get:JsonProperty("status") val status: Order.Status? = null,
 
     @get:JsonProperty("complete") val complete: kotlin.Boolean? = false
-) {
+) : Serializable{
 
     /**
     * Order Status
@@ -48,5 +49,8 @@ data class Order(
         @JsonProperty("delivered") delivered("delivered")
     }
 
+    companion object {
+        private const val serialVersionUID: kotlin.Long = 1
+    }
 }
 

samples/server/petstore/kotlin-spring-cloud/src/main/kotlin/org/openapitools/model/Pet.kt

@@ -5,6 +5,7 @@ import com.fasterxml.jackson.annotation.JsonProperty
 import com.fasterxml.jackson.annotation.JsonValue
 import org.openapitools.model.Category
 import org.openapitools.model.Tag
+import java.io.Serializable
 import javax.validation.constraints.DecimalMax
 import javax.validation.constraints.DecimalMin
 import javax.validation.constraints.Email
@@ -40,7 +41,7 @@ data class Pet(
 
     @Deprecated(message = "")
     @get:JsonProperty("status") val status: Pet.Status? = null
-) {
+) : Serializable{
 
     /**
     * pet status in the store
@@ -53,5 +54,8 @@ data class Pet(
         @JsonProperty("sold") sold("sold")
     }
 
+    companion object {
+        private const val serialVersionUID: kotlin.Long = 1
+    }
 }
 

samples/server/petstore/kotlin-spring-cloud/src/main/kotlin/org/openapitools/model/Tag.kt

@@ -2,6 +2,7 @@ package org.openapitools.model
 
 import java.util.Objects
 import com.fasterxml.jackson.annotation.JsonProperty
+import java.io.Serializable
 import javax.validation.constraints.DecimalMax
 import javax.validation.constraints.DecimalMin
 import javax.validation.constraints.Email
@@ -22,7 +23,10 @@ data class Tag(
     @get:JsonProperty("id") val id: kotlin.Long? = null,
 
     @get:JsonProperty("name") val name: kotlin.String? = null
-) {
+) : Serializable{
 
+    companion object {
+        private const val serialVersionUID: kotlin.Long = 1
+    }
 }
 

samples/server/petstore/kotlin-spring-cloud/src/main/kotlin/org/openapitools/model/User.kt

@@ -2,6 +2,7 @@ package org.openapitools.model
 
 import java.util.Objects
 import com.fasterxml.jackson.annotation.JsonProperty
+import java.io.Serializable
 import javax.validation.constraints.DecimalMax
 import javax.validation.constraints.DecimalMin
 import javax.validation.constraints.Email
@@ -40,7 +41,10 @@ data class User(
     @get:JsonProperty("phone") val phone: kotlin.String? = null,
 
     @get:JsonProperty("userStatus") val userStatus: kotlin.Int? = null
-) {
+) : Serializable{
 
+    companion object {
+        private const val serialVersionUID: kotlin.Long = 1
+    }
 }
 

samples/server/petstore/kotlin-springboot-3/src/main/kotlin/org/openapitools/model/Category.kt

@@ -2,6 +2,7 @@ package org.openapitools.model
 
 import java.util.Objects
 import com.fasterxml.jackson.annotation.JsonProperty
+import java.io.Serializable
 import jakarta.validation.constraints.DecimalMax
 import jakarta.validation.constraints.DecimalMin
 import jakarta.validation.constraints.Email
@@ -23,7 +24,10 @@ data class Category(
 
     @get:Pattern(regexp="^[a-zA-Z0-9]+[a-zA-Z0-9\\.\\-_]*[a-zA-Z0-9]+$")
     @get:JsonProperty("name") val name: kotlin.String? = null
-) {
+) : Serializable{
 
+    companion object {
+        private const val serialVersionUID: kotlin.Long = 1
+    }
 }