Fix Issue #20139

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

@@ -2868,6 +2868,8 @@ protected void updateModelForObject(CodegenModel m, Schema schema) {
         if (ModelUtils.isMapSchema(schema)) {
             // an object or anyType composed schema that has additionalProperties set
             addAdditionPropertiesToCodeGenModel(m, schema);
+        } else if(!ModelUtils.isDisallowAdditionalPropertiesIfNotPresent()) {
+            addAdditionPropertiesToCodeGenModel(m, schema);
         } else if (ModelUtils.isFreeFormObject(schema, openAPI)) {
             // non-composed object type with no properties + additionalProperties
             // additionalProperties must be null, ObjectSchema, or empty Schema

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

@@ -34,6 +34,7 @@
 import org.openapitools.codegen.java.assertions.JavaFileAssert;
 import org.openapitools.codegen.languages.AbstractJavaCodegen;
 import org.openapitools.codegen.languages.JavaClientCodegen;
+import org.openapitools.codegen.languages.KotlinServerCodegen;
 import org.openapitools.codegen.languages.features.BeanValidationFeatures;
 import org.openapitools.codegen.languages.features.CXFServerFeatures;
 import org.openapitools.codegen.meta.features.SecurityFeature;
@@ -56,14 +57,17 @@
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.entry;
 import static org.assertj.core.api.InstanceOfAssertFactories.FILE;
-import static org.openapitools.codegen.CodegenConstants.SERIALIZATION_LIBRARY;
-import static org.openapitools.codegen.TestUtils.newTempFolder;
-import static org.openapitools.codegen.TestUtils.validateJavaSourceFiles;
+import static org.openapitools.codegen.CodegenConstants.*;
+import static org.openapitools.codegen.TestUtils.*;
+import static org.openapitools.codegen.languages.AbstractKotlinCodegen.USE_JAKARTA_EE;
 import static org.openapitools.codegen.languages.JavaClientCodegen.*;
+import static org.openapitools.codegen.languages.KotlinServerCodegen.Constants.INTERFACE_ONLY;
+import static org.openapitools.codegen.languages.KotlinServerCodegen.Constants.JAXRS_SPEC;
 import static org.testng.Assert.*;
 
 public class JavaClientCodegenTest {
@@ -3592,4 +3596,29 @@ public void testClassesAreValidJavaOkHttpGson() {
                 "public some.pkg.B getsomepkgB() throws ClassCastException {"
         );
     }
+
+    @Test(description = "Issue #20139")
+    public void givenAdditionalPropertiesNotDefinedAndIsDisallowAdditionalPropertiesIfNotPresentIsFalseWhenGenerateModelThenAdditionalPropertiesTypeIsObject() throws Exception {
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+
+        JavaClientCodegen codegen = new JavaClientCodegen();
+        codegen.setOutputDir(output.getAbsolutePath());
+        codegen.setUseBeanValidation(true);
+        codegen.additionalProperties().put(DISALLOW_ADDITIONAL_PROPERTIES_IF_NOT_PRESENT, false);
+
+        // Only works for these libraries: jersey3, jersey2, feign, feign-hc5, resttemplate, webclient, restclient native
+        // The default, okhttp-gson, relies on isAdditionalPropertiesTrue and doesn't use additionalPropertiesType
+        codegen.additionalProperties().put(LIBRARY, JERSEY2);
+        new DefaultGenerator().opts(new ClientOptInput()
+                        .openAPI(TestUtils.parseSpec("src/test/resources/2_0/issue_20139.yaml"))
+                        .config(codegen))
+                .generate();
+
+        String outputPath = output.getAbsolutePath() + "/src/main/java/org/openapitools/client";
+        Path jsonWebKey = Paths.get(outputPath + "/model/JsonWebKey.java");
+        JavaFileAssert.assertThat(jsonWebKey)
+                        .assertProperty("additionalProperties")
+                                .withType("Map<String, Object>");
+    }
 }

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

@@ -58,9 +58,12 @@
 
 import static java.util.stream.Collectors.groupingBy;
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.openapitools.codegen.CodegenConstants.DISALLOW_ADDITIONAL_PROPERTIES_IF_NOT_PRESENT;
+import static org.openapitools.codegen.CodegenConstants.LIBRARY;
 import static org.openapitools.codegen.TestUtils.*;
 import static org.openapitools.codegen.languages.AbstractJavaCodegen.GENERATE_BUILDERS;
 import static org.openapitools.codegen.languages.AbstractJavaCodegen.GENERATE_CONSTRUCTOR_WITH_ALL_ARGS;
+import static org.openapitools.codegen.languages.JavaClientCodegen.JERSEY2;
 import static org.openapitools.codegen.languages.SpringCodegen.*;
 import static org.openapitools.codegen.languages.features.DocumentationProviderFeatures.ANNOTATION_LIBRARY;
 import static org.openapitools.codegen.languages.features.DocumentationProviderFeatures.DOCUMENTATION_PROVIDER;
@@ -5501,4 +5504,25 @@ public void testEnumFieldShouldBeFinal_issue21018() throws IOException {
         JavaFileAssert.assertThat(files.get("SomeObject.java"))
                 .fileContains("private final String value");
     }
+
+    @Test(description = "Issue #20139")
+    public void givenAdditionalPropertiesNotDefinedAndIsDisallowAdditionalPropertiesIfNotPresentIsFalseWhenGenerateModelThenAdditionalPropertiesTypeIsObject() throws Exception {
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+
+        SpringCodegen codegen = new SpringCodegen();
+        codegen.setOutputDir(output.getAbsolutePath());
+        codegen.setUseBeanValidation(true);
+        codegen.additionalProperties().put(DISALLOW_ADDITIONAL_PROPERTIES_IF_NOT_PRESENT, false);
+        new DefaultGenerator().opts(new ClientOptInput()
+                        .openAPI(TestUtils.parseSpec("src/test/resources/2_0/issue_20139.yaml"))
+                        .config(codegen))
+                .generate();
+
+        String outputPath = output.getAbsolutePath() + "/src/main/java/org/openapitools";
+        Path jsonWebKey = Paths.get(outputPath + "/model/JsonWebKey.java");
+        JavaFileAssert.assertThat(jsonWebKey)
+                .assertProperty("additionalProperties")
+                .withType("Map<String, Object>");
+    }
 }

modules/openapi-generator/src/test/resources/2_0/issue_20139.yaml

@@ -0,0 +1,23 @@
+swagger: '2.0'
+info:
+  version: '1.0'
+  title: FooBar
+paths:
+  /jwks:
+    get:
+      operationId: getJwks
+      responses:
+        200:
+          description: "Success"
+          schema:
+            type: "array"
+            items:
+              $ref: "#/definitions/JsonWebKey"
+definitions:
+  JsonWebKey:
+    title: JSON Web Key
+    type: object
+    properties:
+      kid:
+        type: string
+    # No additionalProperties specified

modules/openapi-generator/src/test/resources/3_0/java/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml

@@ -1969,11 +1969,13 @@ components:
           type: string
           pattern: /^[A-Z\s]*$/i
       nullable: true
+      additionalProperties: false
     banana:
       type: object
       properties:
         lengthCm:
           type: number
+      additionalProperties: false
     mammal:
       oneOf:
         - $ref: '#/components/schemas/whale'

samples/client/petstore/java/jersey3/api/openapi.yaml

@@ -2038,6 +2038,7 @@ components:
         color:
           type: string
     apple:
+      additionalProperties: false
       nullable: true
       properties:
         cultivar:
@@ -2048,6 +2049,7 @@ components:
           type: string
       type: object
     banana:
+      additionalProperties: false
       properties:
         lengthCm:
           type: number

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java

@@ -15,6 +15,10 @@
 
 import org.apache.commons.lang3.builder.EqualsBuilder;
 import org.apache.commons.lang3.builder.HashCodeBuilder;
+import java.util.Map;
+import java.util.HashMap;
+import com.fasterxml.jackson.annotation.JsonAnyGetter;
+import com.fasterxml.jackson.annotation.JsonAnySetter;
 import java.util.Objects;
 import java.util.Map;
 import java.util.HashMap;
@@ -333,6 +337,43 @@ public void setMapWithUndeclaredPropertiesString(@jakarta.annotation.Nullable Ma
     this.mapWithUndeclaredPropertiesString = mapWithUndeclaredPropertiesString;
   }
 
+  /**
+   * A container for additional, undeclared properties.
+   * This is a holder for any undeclared properties as specified with
+   * the 'additionalProperties' keyword in the OAS document.
+   */
+  private Map<String, Object> additionalProperties;
+
+  /**
+   * Set the additional (undeclared) property with the specified name and value.
+   * If the property does not already exist, create it otherwise replace it.
+   */
+  @JsonAnySetter
+  public AdditionalPropertiesClass putAdditionalProperty(String key, Object value) {
+    if (this.additionalProperties == null) {
+        this.additionalProperties = new HashMap<>();
+    }
+    this.additionalProperties.put(key, value);
+    return this;
+  }
+
+  /**
+   * Return the additional (undeclared) property.
+   */
+  @JsonAnyGetter
+  public Map<String, Object> getAdditionalProperties() {
+    return additionalProperties;
+  }
+
+  /**
+   * Return the additional (undeclared) property with the specified name.
+   */
+  public Object getAdditionalProperty(String key) {
+    if (this.additionalProperties == null) {
+        return null;
+    }
+    return this.additionalProperties.get(key);
+  }
 
   /**
    * Return true if this AdditionalPropertiesClass object is equal to o.
@@ -370,6 +411,7 @@ public String toString() {
     sb.append("    mapWithUndeclaredPropertiesAnytype3: ").append(toIndentedString(mapWithUndeclaredPropertiesAnytype3)).append("\n");
     sb.append("    emptyMap: ").append(toIndentedString(emptyMap)).append("\n");
     sb.append("    mapWithUndeclaredPropertiesString: ").append(toIndentedString(mapWithUndeclaredPropertiesString)).append("\n");
+    sb.append("    additionalProperties: ").append(toIndentedString(additionalProperties)).append("\n");
     sb.append("}");
     return sb.toString();
   }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Animal.java

@@ -15,6 +15,10 @@
 
 import org.apache.commons.lang3.builder.EqualsBuilder;
 import org.apache.commons.lang3.builder.HashCodeBuilder;
+import java.util.Map;
+import java.util.HashMap;
+import com.fasterxml.jackson.annotation.JsonAnyGetter;
+import com.fasterxml.jackson.annotation.JsonAnySetter;
 import java.util.Objects;
 import java.util.Map;
 import java.util.HashMap;
@@ -115,6 +119,43 @@ public void setColor(@jakarta.annotation.Nullable String color) {
     this.color = color;
   }
 
+  /**
+   * A container for additional, undeclared properties.
+   * This is a holder for any undeclared properties as specified with
+   * the 'additionalProperties' keyword in the OAS document.
+   */
+  private Map<String, Object> additionalProperties;
+
+  /**
+   * Set the additional (undeclared) property with the specified name and value.
+   * If the property does not already exist, create it otherwise replace it.
+   */
+  @JsonAnySetter
+  public Animal putAdditionalProperty(String key, Object value) {
+    if (this.additionalProperties == null) {
+        this.additionalProperties = new HashMap<>();
+    }
+    this.additionalProperties.put(key, value);
+    return this;
+  }
+
+  /**
+   * Return the additional (undeclared) property.
+   */
+  @JsonAnyGetter
+  public Map<String, Object> getAdditionalProperties() {
+    return additionalProperties;
+  }
+
+  /**
+   * Return the additional (undeclared) property with the specified name.
+   */
+  public Object getAdditionalProperty(String key) {
+    if (this.additionalProperties == null) {
+        return null;
+    }
+    return this.additionalProperties.get(key);
+  }
 
   /**
    * Return true if this Animal object is equal to o.
@@ -135,6 +176,7 @@ public String toString() {
     sb.append("class Animal {\n");
     sb.append("    className: ").append(toIndentedString(className)).append("\n");
     sb.append("    color: ").append(toIndentedString(color)).append("\n");
+    sb.append("    additionalProperties: ").append(toIndentedString(additionalProperties)).append("\n");
     sb.append("}");
     return sb.toString();
   }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java

@@ -15,6 +15,10 @@
 
 import org.apache.commons.lang3.builder.EqualsBuilder;
 import org.apache.commons.lang3.builder.HashCodeBuilder;
+import java.util.Map;
+import java.util.HashMap;
+import com.fasterxml.jackson.annotation.JsonAnyGetter;
+import com.fasterxml.jackson.annotation.JsonAnySetter;
 import java.util.Objects;
 import java.util.Map;
 import java.util.HashMap;
@@ -82,6 +86,43 @@ public void setArrayArrayNumber(@jakarta.annotation.Nullable List<List<BigDecima
     this.arrayArrayNumber = arrayArrayNumber;
   }
 
+  /**
+   * A container for additional, undeclared properties.
+   * This is a holder for any undeclared properties as specified with
+   * the 'additionalProperties' keyword in the OAS document.
+   */
+  private Map<String, Object> additionalProperties;
+
+  /**
+   * Set the additional (undeclared) property with the specified name and value.
+   * If the property does not already exist, create it otherwise replace it.
+   */
+  @JsonAnySetter
+  public ArrayOfArrayOfNumberOnly putAdditionalProperty(String key, Object value) {
+    if (this.additionalProperties == null) {
+        this.additionalProperties = new HashMap<>();
+    }
+    this.additionalProperties.put(key, value);
+    return this;
+  }
+
+  /**
+   * Return the additional (undeclared) property.
+   */
+  @JsonAnyGetter
+  public Map<String, Object> getAdditionalProperties() {
+    return additionalProperties;
+  }
+
+  /**
+   * Return the additional (undeclared) property with the specified name.
+   */
+  public Object getAdditionalProperty(String key) {
+    if (this.additionalProperties == null) {
+        return null;
+    }
+    return this.additionalProperties.get(key);
+  }
 
   /**
    * Return true if this ArrayOfArrayOfNumberOnly object is equal to o.
@@ -101,6 +142,7 @@ public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class ArrayOfArrayOfNumberOnly {\n");
     sb.append("    arrayArrayNumber: ").append(toIndentedString(arrayArrayNumber)).append("\n");
+    sb.append("    additionalProperties: ").append(toIndentedString(additionalProperties)).append("\n");
     sb.append("}");
     return sb.toString();
   }