addd flag for media type example set value

modules/swagger-core/src/main/java/io/swagger/v3/core/jackson/mixin/ExampleMixin.java

@@ -0,0 +1,23 @@
+package io.swagger.v3.core.jackson.mixin;
+
+import com.fasterxml.jackson.annotation.JsonAnyGetter;
+import com.fasterxml.jackson.annotation.JsonAnySetter;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonInclude;
+
+import java.util.Map;
+
+public abstract class ExampleMixin {
+
+    @JsonAnyGetter
+    public abstract Map<String, Object> getExtensions();
+
+    @JsonAnySetter
+    public abstract void addExtension(String name, Object value);
+
+    @JsonInclude(JsonInclude.Include.CUSTOM)
+    public abstract Object getValue();
+
+    @JsonIgnore
+    public abstract boolean getValueSetFlag();
+}

modules/swagger-core/src/main/java/io/swagger/v3/core/jackson/mixin/MediaTypeMixin.java

@@ -0,0 +1,23 @@
+package io.swagger.v3.core.jackson.mixin;
+
+import com.fasterxml.jackson.annotation.JsonAnyGetter;
+import com.fasterxml.jackson.annotation.JsonAnySetter;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonInclude;
+
+import java.util.Map;
+
+public abstract class MediaTypeMixin {
+
+    @JsonAnyGetter
+    public abstract Map<String, Object> getExtensions();
+
+    @JsonAnySetter
+    public abstract void addExtension(String name, Object value);
+
+    @JsonIgnore
+    public abstract boolean getExampleSetFlag();
+
+    @JsonInclude(JsonInclude.Include.CUSTOM)
+    public abstract Object getExample();
+}

modules/swagger-core/src/main/java/io/swagger/v3/core/util/ObjectMapperFactory.java

@@ -17,7 +17,9 @@
 import io.swagger.v3.core.jackson.SchemaSerializer;
 import io.swagger.v3.core.jackson.mixin.ComponentsMixin;
 import io.swagger.v3.core.jackson.mixin.DateSchemaMixin;
+import io.swagger.v3.core.jackson.mixin.ExampleMixin;
 import io.swagger.v3.core.jackson.mixin.ExtensionsMixin;
+import io.swagger.v3.core.jackson.mixin.MediaTypeMixin;
 import io.swagger.v3.core.jackson.mixin.OpenAPIMixin;
 import io.swagger.v3.core.jackson.mixin.OperationMixin;
 import io.swagger.v3.core.jackson.mixin.SchemaMixin;
@@ -107,14 +109,14 @@ public JsonSerializer<?> modifySerializer(
         sourceMixins.put(Contact.class, ExtensionsMixin.class);
         sourceMixins.put(Encoding.class, ExtensionsMixin.class);
         sourceMixins.put(EncodingProperty.class, ExtensionsMixin.class);
-        sourceMixins.put(Example.class, ExtensionsMixin.class);
+        sourceMixins.put(Example.class, ExampleMixin.class);
         sourceMixins.put(ExternalDocumentation.class, ExtensionsMixin.class);
         sourceMixins.put(Header.class, ExtensionsMixin.class);
         sourceMixins.put(Info.class, ExtensionsMixin.class);
         sourceMixins.put(License.class, ExtensionsMixin.class);
         sourceMixins.put(Link.class, ExtensionsMixin.class);
         sourceMixins.put(LinkParameter.class, ExtensionsMixin.class);
-        sourceMixins.put(MediaType.class, ExtensionsMixin.class);
+        sourceMixins.put(MediaType.class, MediaTypeMixin.class);
         sourceMixins.put(OAuthFlow.class, ExtensionsMixin.class);
         sourceMixins.put(OAuthFlows.class, ExtensionsMixin.class);
         sourceMixins.put(OpenAPI.class, OpenAPIMixin.class);

modules/swagger-core/src/test/java/io/swagger/v3/core/deserialization/JsonDeserializationTest.java

@@ -17,8 +17,10 @@
 import io.swagger.v3.oas.models.responses.ApiResponses;
 import io.swagger.v3.oas.models.security.SecurityRequirement;
 import io.swagger.v3.oas.models.security.SecurityScheme;
+import org.apache.commons.io.FileUtils;
 import org.testng.annotations.Test;
 
+import java.io.File;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.List;
@@ -409,4 +411,20 @@ public void testNullExampleDeserialization() throws Exception {
         Yaml.prettyPrint(oas);
     }
 
+    @Test
+    public void testExampleDeserializationOnMediaType() throws Exception {
+        String content = FileUtils.readFileToString(new File("src/test/resources/specFiles/media-type-null-example.yaml"), "UTF-8");
+        OpenAPI openAPI = Yaml.mapper().readValue(content, OpenAPI.class);
+
+        assertNull(openAPI.getPaths().get("/pets/{petId}").getGet().getResponses().get("200").getContent().get("application/json").getExample());
+        assertTrue(openAPI.getPaths().get("/pets/{petId}").getGet().getResponses().get("200").getContent().get("application/json").getExampleSetFlag());
+
+        assertNull(openAPI.getPaths().get("/pet").getPost().getResponses().get("200").getContent().get("application/json").getExample());
+        assertFalse(openAPI.getPaths().get("/pet").getPost().getResponses().get("200").getContent().get("application/json").getExampleSetFlag());
+
+        assertNotNull(openAPI.getPaths().get("/pet").getPost().getRequestBody().getContent().get("application/json").getExample());
+
+        assertTrue(openAPI.getPaths().get("/pet").getPost().getRequestBody().getContent().get("application/json").getExampleSetFlag());
+    }
+
 }

modules/swagger-core/src/test/resources/specFiles/media-type-null-example.yaml

@@ -0,0 +1,68 @@
+openapi: "3.0.1"
+info:
+  version: 1.0.0
+  title: Swagger Petstore
+  license:
+    name: MIT
+servers:
+  - url: https://petstore3.swagger.io/api/v3
+paths:
+  /pet:
+    post:
+      tags:
+      - pet
+      summary: Add a new pet to the store
+      operationId: addPet
+      requestBody:
+        description: Pet object that needs to be added to the store
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/Pet'
+            example:
+              id: 10
+              name: kitty
+              tag: something
+        required: true
+      responses:
+        200:
+          description: Expected response to a valid request
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Pet"
+  /pets/{petId}:
+    get:
+      summary: Info for a specific pet
+      operationId: showPetById
+      tags:
+        - pets
+      parameters:
+        - name: petId
+          in: path
+          required: true
+          description: The id of the pet to retrieve
+          schema:
+            type: string
+      responses:
+        200:
+          description: Expected response to a valid request
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Pet"
+              example: null
+components:
+  schemas:
+    Pet:
+      required:
+        - id
+        - name
+      properties:
+        id:
+          type: integer
+          format: int64
+        name:
+          type: string
+        tag:
+          type: string

modules/swagger-models/src/main/java/io/swagger/v3/oas/models/examples/Example.java

@@ -28,6 +28,8 @@ public class Example {
     private String $ref = null;
     private java.util.Map<String, Object> extensions = null;
 
+    private boolean valueSetFlag;
+
     /**
      * returns the summary property from a Example instance.
      *
@@ -78,10 +80,11 @@ public Object getValue() {
 
     public void setValue(Object value) {
         this.value = value;
+        valueSetFlag = true;
     }
 
     public Example value(Object value) {
-        this.value = value;
+        setValue(value);
         return this;
     }
 
@@ -143,6 +146,14 @@ public Example extensions(java.util.Map<String, Object> extensions) {
         return this;
     }
 
+    public boolean getValueSetFlag() {
+        return valueSetFlag;
+    }
+
+    public void setValueSetFlag(boolean valueSetFlag) {
+        this.valueSetFlag = valueSetFlag;
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) {

modules/swagger-models/src/main/java/io/swagger/v3/oas/models/media/MediaType.java

@@ -35,6 +35,8 @@ public class MediaType {
     private Map<String, Encoding> encoding = null;
     private java.util.Map<String, Object> extensions = null;
 
+    private boolean exampleSetFlag;
+
     /**
      * returns the schema property from a MediaType instance.
      *
@@ -93,10 +95,11 @@ public Object getExample() {
 
     public void setExample(Object example) {
         this.example = example;
+        exampleSetFlag = true;
     }
 
     public MediaType example(Object example) {
-        this.example = example;
+        setExample(example);
         return this;
     }
 
@@ -127,6 +130,14 @@ public MediaType addEncoding(String key, Encoding encodingItem) {
         return this;
     }
 
+    public boolean getExampleSetFlag() {
+        return exampleSetFlag;
+    }
+
+    public void setExampleSetFlag(boolean exampleSetFlag) {
+        this.exampleSetFlag = exampleSetFlag;
+    }
+
     @Override
     public boolean equals(java.lang.Object o) {
         if (this == o) {