BAEL-3325: Programmatic generation of JSON Schemas in Java (#14498)

* BAEL-3325: Programmatic Generation of JSON Schemas in Java

* BAEL-3325: fix typo

* BAEL-3325: rerun baeldung intellij formatter

* BAEL-3325: static imports

json-modules/json-2/pom.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>json-2</artifactId>
     <version>0.0.1-SNAPSHOT</version>
@@ -123,6 +123,26 @@
             <artifactId>javax.annotation-api</artifactId>
             <version>1.3.2</version>
         </dependency>
+        <dependency>
+            <groupId>com.github.victools</groupId>
+            <artifactId>jsonschema-generator</artifactId>
+            <version>${jsonschema-generator.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.github.victools</groupId>
+            <artifactId>jsonschema-module-jackson</artifactId>
+            <version>${jsonschema-generator.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>jakarta.validation</groupId>
+            <artifactId>jakarta.validation-api</artifactId>
+            <version>${jakarta.validation.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.github.victools</groupId>
+            <artifactId>jsonschema-module-jakarta-validation</artifactId>
+            <version>${jsonschema-generator.version}</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -162,6 +182,55 @@
                 </plugin>
             </plugins>
         </pluginManagement>
+        <plugins>
+            <plugin>
+                <groupId>com.github.victools</groupId>
+                <artifactId>jsonschema-maven-plugin</artifactId>
+                <version>${jsonschema-generator.version}</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>generate</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <packageNames>
+                        <packageName>com.baeldung.jsonschemageneration.plugin</packageName>
+                    </packageNames>
+                    <classNames>
+                        <className>com.baeldung.jsonschemageneration.plugin.Person</className>
+                    </classNames>
+                    <schemaVersion>DRAFT_2020_12</schemaVersion>
+                    <schemaFilePath>src/main/resources/schemas</schemaFilePath>
+                    <schemaFileName>{1}/{0}.json</schemaFileName>
+                    <failIfNoClassesMatch>true</failIfNoClassesMatch>
+                    <options>
+                        <preset>PLAIN_JSON</preset>
+                        <enabled>
+                            <option>DEFINITIONS_FOR_ALL_OBJECTS</option>
+                            <option>FORBIDDEN_ADDITIONAL_PROPERTIES_BY_DEFAULT</option>
+                        </enabled>
+                        <disabled>SCHEMA_VERSION_INDICATOR</disabled>
+                    </options>
+                    <modules>
+                        <module>
+                            <name>Jackson</name>
+                            <options>
+                                <option>RESPECT_JSONPROPERTY_REQUIRED</option>
+                            </options>
+                        </module>
+                        <module>
+                            <name>JakartaValidation</name>
+                            <options>
+                                <option>NOT_NULLABLE_FIELD_IS_REQUIRED</option>
+                                <option>INCLUDE_PATTERN_EXPRESSIONS</option>
+                            </options>
+                        </module>
+                    </modules>
+                </configuration>
+            </plugin>
+        </plugins>
     </build>
 
     <properties>
@@ -173,6 +242,8 @@
         <jackson-jsonld.version>0.1.1</jackson-jsonld.version>
         <hydra-jsonld.version>0.4.2</hydra-jsonld.version>
         <jsonld-java.version>0.13.0</jsonld-java.version>
+        <jsonschema-generator.version>4.31.1</jsonschema-generator.version>
+        <jakarta.validation.version>3.0.2</jakarta.validation.version>
     </properties>
 
 </project>

json-modules/json-2/src/main/java/com/baeldung/jsonschemageneration/configuration/AdvancedArticle.java

@@ -0,0 +1,70 @@
+package com.baeldung.jsonschemageneration.configuration;
+
+import java.sql.Timestamp;
+import java.util.Date;
+import java.util.UUID;
+
+enum Area {
+    JAVA("JAVA"), KOTLIN("KOTLIN"), SCALA("SCALA"), LINUX("LINUX");
+
+    private final String area;
+
+    Area(String area) {
+        this.area = area;
+    }
+
+    public String getArea() {
+        return area;
+    }
+}
+
+public class AdvancedArticle {
+    private UUID id;
+    private String title;
+
+    private String content;
+
+    @AllowedTypes({ Timestamp.class, Date.class })
+    private Object createdAt;
+    private Area area;
+
+    public Area getArea() {
+        return area;
+    }
+
+    public void setArea(Area area) {
+        this.area = area;
+    }
+
+    public Object getCreatedAt() {
+        return createdAt;
+    }
+
+    public void setCreatedAt(Object createdAt) {
+        this.createdAt = createdAt;
+    }
+
+    public UUID getId() {
+        return id;
+    }
+
+    public void setId(UUID id) {
+        this.id = id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getContent() {
+        return content;
+    }
+
+    public void setContent(String content) {
+        this.content = content;
+    }
+}

json-modules/json-2/src/main/java/com/baeldung/jsonschemageneration/configuration/AdvancedConfigurationSchemaGenerator.java

@@ -0,0 +1,39 @@
+package com.baeldung.jsonschemageneration.configuration;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.github.victools.jsonschema.generator.Option;
+import com.github.victools.jsonschema.generator.OptionPreset;
+import com.github.victools.jsonschema.generator.SchemaGenerator;
+import com.github.victools.jsonschema.generator.SchemaGeneratorConfig;
+import com.github.victools.jsonschema.generator.SchemaGeneratorConfigBuilder;
+import com.github.victools.jsonschema.generator.SchemaVersion;
+
+import java.util.Optional;
+import java.util.UUID;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+public class AdvancedConfigurationSchemaGenerator {
+    public static void main(String[] args) {
+
+        SchemaGeneratorConfigBuilder configBuilder = new SchemaGeneratorConfigBuilder(SchemaVersion.DRAFT_2020_12, OptionPreset.PLAIN_JSON);
+
+        configBuilder.forFields().withInstanceAttributeOverride((node, field, context) -> node.put("readOnly", field.getDeclaredType().isInstanceOf(UUID.class)));
+
+        configBuilder.forFields()
+          .withTargetTypeOverridesResolver(field -> Optional.ofNullable(field.getAnnotationConsideringFieldAndGetterIfSupported(AllowedTypes.class))
+            .map(AllowedTypes::value)
+            .map(Stream::of)
+            .map(stream -> stream.map(subtype -> field.getContext().resolve(subtype)))
+            .map(stream -> stream.collect(Collectors.toList()))
+            .orElse(null));
+
+        SchemaGeneratorConfig config = configBuilder.with(Option.EXTRA_OPEN_API_FORMAT_VALUES).build();
+
+        SchemaGenerator generator = new SchemaGenerator(config);
+        JsonNode jsonSchema = generator.generateSchema(AdvancedArticle.class);
+
+        System.out.println(jsonSchema.toPrettyString());
+    }
+
+}

json-modules/json-2/src/main/java/com/baeldung/jsonschemageneration/configuration/AllowedTypes.java

@@ -0,0 +1,13 @@
+package com.baeldung.jsonschemageneration.configuration;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.FIELD)
+public @interface AllowedTypes {
+    Class<?>[] value();
+}
+

json-modules/json-2/src/main/java/com/baeldung/jsonschemageneration/configuration/IndividualConfigurationSchemaGenerator.java

@@ -0,0 +1,44 @@
+package com.baeldung.jsonschemageneration.configuration;
+
+import com.baeldung.jsonschemageneration.recursive.Author;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.github.victools.jsonschema.generator.Option;
+import com.github.victools.jsonschema.generator.OptionPreset;
+import com.github.victools.jsonschema.generator.SchemaGenerator;
+import com.github.victools.jsonschema.generator.SchemaGeneratorConfig;
+import com.github.victools.jsonschema.generator.SchemaGeneratorConfigBuilder;
+import com.github.victools.jsonschema.generator.SchemaVersion;
+
+import javax.annotation.Nullable;
+import javax.validation.constraints.NotNull;
+import java.time.Instant;
+import java.util.Collections;
+import java.util.Date;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+public class IndividualConfigurationSchemaGenerator {
+    public static void main(String[] args) {
+
+        SchemaGeneratorConfigBuilder configBuilder = new SchemaGeneratorConfigBuilder(SchemaVersion.DRAFT_2020_12, OptionPreset.PLAIN_JSON);
+
+        configBuilder.forFields().withRequiredCheck(field -> field.getAnnotationConsideringFieldAndGetter(Nullable.class) == null).withArrayUniqueItemsResolver(scope -> scope.getType().getErasedType() == (List.class) ? true : null);
+
+        configBuilder.forMethods().withRequiredCheck(method -> method.getAnnotationConsideringFieldAndGetter(NotNull.class) != null);
+
+        configBuilder.forTypesInGeneral()
+          .withArrayUniqueItemsResolver(scope -> scope.getType().getErasedType() == (List.class) ? true : null)
+          .withDefaultResolver(scope -> scope.getType().getErasedType() == List.class ? Collections.EMPTY_LIST : null)
+          .withDefaultResolver(scope -> scope.getType().getErasedType() == Date.class ? Date.from(Instant.now()) : null)
+          .withEnumResolver(scope -> scope.getType().getErasedType().isEnum() ? Stream.of(scope.getType().getErasedType().getEnumConstants()).map(v -> ((Enum<?>) v).name()).collect(Collectors.toList()) : null);
+
+        SchemaGeneratorConfig config = configBuilder.with(Option.EXTRA_OPEN_API_FORMAT_VALUES).build();
+
+        SchemaGenerator generator = new SchemaGenerator(config);
+        JsonNode jsonSchema = generator.generateSchema(Author.class);
+
+        System.out.println(jsonSchema.toPrettyString());
+    }
+
+}

json-modules/json-2/src/main/java/com/baeldung/jsonschemageneration/modules/JacksonModuleSchemaGenerator.java

@@ -0,0 +1,68 @@
+package com.baeldung.jsonschemageneration.modules;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.github.victools.jsonschema.generator.SchemaGenerator;
+import com.github.victools.jsonschema.generator.SchemaGeneratorConfigBuilder;
+import com.github.victools.jsonschema.module.jackson.JacksonModule;
+
+import java.util.Date;
+import java.util.List;
+import java.util.UUID;
+
+import static com.github.victools.jsonschema.generator.Option.EXTRA_OPEN_API_FORMAT_VALUES;
+import static com.github.victools.jsonschema.generator.OptionPreset.PLAIN_JSON;
+import static com.github.victools.jsonschema.generator.SchemaVersion.DRAFT_2020_12;
+import static com.github.victools.jsonschema.module.jackson.JacksonOption.RESPECT_JSONPROPERTY_REQUIRED;
+
+public class JacksonModuleSchemaGenerator {
+    public static void main(String[] args) {
+
+        JacksonModule module = new JacksonModule(RESPECT_JSONPROPERTY_REQUIRED);
+        SchemaGeneratorConfigBuilder configBuilder = new SchemaGeneratorConfigBuilder(DRAFT_2020_12, PLAIN_JSON).with(module).with(EXTRA_OPEN_API_FORMAT_VALUES);
+
+        SchemaGenerator generator = new SchemaGenerator(configBuilder.build());
+        JsonNode jsonSchema = generator.generateSchema(Person.class);
+
+        System.out.println(jsonSchema.toPrettyString());
+    }
+
+    static class Person {
+
+        @JsonProperty(access = JsonProperty.Access.READ_ONLY)
+        UUID id;
+
+        @JsonProperty(access = JsonProperty.Access.READ_WRITE, required = true)
+        String name;
+
+        @JsonProperty(access = JsonProperty.Access.READ_WRITE, required = true)
+        String surname;
+
+        @JsonProperty(access = JsonProperty.Access.READ_WRITE, required = true)
+        Address address;
+
+        @JsonIgnore
+        String fullName;
+
+        @JsonProperty(access = JsonProperty.Access.READ_ONLY)
+        Date createdAt;
+
+        @JsonProperty(access = JsonProperty.Access.READ_WRITE)
+        List<Person> friends;
+
+    }
+
+    static class Address {
+
+        @JsonProperty()
+        String street;
+
+        @JsonProperty(required = true)
+        String city;
+
+        @JsonProperty(required = true)
+        String country;
+    }
+
+}

json-modules/json-2/src/main/java/com/baeldung/jsonschemageneration/modules/JakartaValidationModuleSchemaGenerator.java

@@ -0,0 +1,63 @@
+package com.baeldung.jsonschemageneration.modules;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.github.victools.jsonschema.generator.SchemaGenerator;
+import com.github.victools.jsonschema.generator.SchemaGeneratorConfigBuilder;
+import com.github.victools.jsonschema.module.jakarta.validation.JakartaValidationModule;
+import jakarta.validation.constraints.Email;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Null;
+import jakarta.validation.constraints.Pattern;
+import jakarta.validation.constraints.Size;
+
+import java.util.Date;
+import java.util.List;
+import java.util.UUID;
+
+import static com.github.victools.jsonschema.generator.OptionPreset.PLAIN_JSON;
+import static com.github.victools.jsonschema.generator.SchemaVersion.DRAFT_2020_12;
+import static com.github.victools.jsonschema.module.jakarta.validation.JakartaValidationOption.INCLUDE_PATTERN_EXPRESSIONS;
+import static com.github.victools.jsonschema.module.jakarta.validation.JakartaValidationOption.NOT_NULLABLE_FIELD_IS_REQUIRED;
+
+public class JakartaValidationModuleSchemaGenerator {
+    public static void main(String[] args) {
+
+        JakartaValidationModule module = new JakartaValidationModule(NOT_NULLABLE_FIELD_IS_REQUIRED, INCLUDE_PATTERN_EXPRESSIONS);
+        SchemaGeneratorConfigBuilder configBuilder = new SchemaGeneratorConfigBuilder(DRAFT_2020_12, PLAIN_JSON).with(module);
+
+        SchemaGenerator generator = new SchemaGenerator(configBuilder.build());
+        JsonNode jsonSchema = generator.generateSchema(Person.class);
+
+        System.out.println(jsonSchema.toPrettyString());
+    }
+
+    static class Person {
+
+        @NotNull UUID id;
+
+        @NotNull String name;
+
+        @NotNull @Email @Pattern(regexp = "\\b[A-Za-z0-9._%+-]+@baeldung\\.com\\b") String email;
+
+        @NotNull String surname;
+
+        @NotNull Address address;
+
+        @Null String fullName;
+
+        @NotNull Date createdAt;
+
+        @Size(max = 10) List<Person> friends;
+
+    }
+
+    static class Address {
+
+        @Null String street;
+
+        @NotNull String city;
+
+        @NotNull String country;
+    }
+
+}

json-modules/json-2/src/main/java/com/baeldung/jsonschemageneration/plugin/Person.java

@@ -0,0 +1,61 @@
+package com.baeldung.jsonschemageneration.plugin;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import jakarta.validation.constraints.Email;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Null;
+import jakarta.validation.constraints.Pattern;
+import jakarta.validation.constraints.Size;
+
+import java.util.Date;
+import java.util.List;
+import java.util.UUID;
+
+public class Person {
+
+    @NotNull
+    @JsonProperty(access = JsonProperty.Access.READ_ONLY)
+    UUID id;
+
+    @NotNull
+    @JsonProperty(access = JsonProperty.Access.READ_WRITE, required = true)
+    String name;
+
+    @NotNull
+    @JsonProperty(access = JsonProperty.Access.READ_WRITE, required = true)
+    @Email @Pattern(regexp = "\\b[A-Za-z0-9._%+-]+@baeldung\\.com\\b") String email;
+
+    @NotNull
+    @JsonProperty(access = JsonProperty.Access.READ_WRITE, required = true)
+
+    String surname;
+
+    @NotNull
+    @JsonProperty(access = JsonProperty.Access.READ_WRITE, required = true)
+    Address address;
+
+    @Null String fullName;
+
+    @JsonProperty(access = JsonProperty.Access.READ_ONLY)
+    Date createdAt;
+
+    @Size(max = 10)
+    @JsonProperty(access = JsonProperty.Access.READ_WRITE)
+    List<Person> friends;
+
+}
+
+class Address {
+
+    @Null
+    @JsonProperty
+    String street;
+
+    @NotNull
+    @JsonProperty(required = true)
+    String city;
+
+    @NotNull
+    @JsonProperty(required = true)
+    String country;
+}

json-modules/json-2/src/main/java/com/baeldung/jsonschemageneration/recursive/Author.java

@@ -0,0 +1,12 @@
+package com.baeldung.jsonschemageneration.recursive;
+
+import java.util.List;
+import java.util.UUID;
+
+public class Author {
+    private UUID id;
+    private String name;
+    private String role;
+
+    private List<AuthoredArticle> articles;
+}

json-modules/json-2/src/main/java/com/baeldung/jsonschemageneration/recursive/AuthoredArticle.java

@@ -0,0 +1,68 @@
+package com.baeldung.jsonschemageneration.recursive;
+
+import java.util.Date;
+import java.util.UUID;
+
+enum Area {
+    JAVA("JAVA"), KOTLIN("KOTLIN"), SCALA("SCALA"), LINUX("LINUX");
+
+    private final String area;
+
+    Area(String area) {
+        this.area = area;
+    }
+
+    public String getArea() {
+        return area;
+    }
+}
+
+public class AuthoredArticle {
+    private UUID id;
+    private String title;
+    private String content;
+    private Date createdAt;
+    private Area area;
+
+    private Author author;
+
+    public Area getArea() {
+        return area;
+    }
+
+    public void setArea(Area area) {
+        this.area = area;
+    }
+
+    public Date getCreatedAt() {
+        return createdAt;
+    }
+
+    public void setCreatedAt(Date createdAt) {
+        this.createdAt = createdAt;
+    }
+
+    public UUID getId() {
+        return id;
+    }
+
+    public void setId(UUID id) {
+        this.id = id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getContent() {
+        return content;
+    }
+
+    public void setContent(String content) {
+        this.content = content;
+    }
+}

json-modules/json-2/src/main/java/com/baeldung/jsonschemageneration/recursive/RecursiveSchemaGenerator.java

@@ -0,0 +1,23 @@
+package com.baeldung.jsonschemageneration.recursive;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.github.victools.jsonschema.generator.Option;
+import com.github.victools.jsonschema.generator.OptionPreset;
+import com.github.victools.jsonschema.generator.SchemaGenerator;
+import com.github.victools.jsonschema.generator.SchemaGeneratorConfig;
+import com.github.victools.jsonschema.generator.SchemaGeneratorConfigBuilder;
+import com.github.victools.jsonschema.generator.SchemaVersion;
+
+public class RecursiveSchemaGenerator {
+    public static void main(String[] args) {
+
+        SchemaGeneratorConfigBuilder configBuilder = new SchemaGeneratorConfigBuilder(SchemaVersion.DRAFT_2020_12, OptionPreset.PLAIN_JSON);
+        SchemaGeneratorConfig config = configBuilder.with(Option.EXTRA_OPEN_API_FORMAT_VALUES).without(Option.FLATTENED_ENUMS_FROM_TOSTRING).build();
+
+        SchemaGenerator generator = new SchemaGenerator(config);
+        JsonNode jsonSchema = generator.generateSchema(AuthoredArticle.class);
+
+        System.out.println(jsonSchema.toPrettyString());
+    }
+
+}

json-modules/json-2/src/main/java/com/baeldung/jsonschemageneration/simple/Article.java

@@ -0,0 +1,66 @@
+package com.baeldung.jsonschemageneration.simple;
+
+import java.util.Date;
+import java.util.UUID;
+
+enum Area {
+    JAVA("JAVA"), KOTLIN("KOTLIN"), SCALA("SCALA"), LINUX("LINUX");
+
+    private final String area;
+
+    Area(String area) {
+        this.area = area;
+    }
+
+    public String getArea() {
+        return area;
+    }
+}
+
+public class Article {
+    private UUID id;
+    private String title;
+    private String content;
+    private Date createdAt;
+    private Area area;
+
+    public Area getArea() {
+        return area;
+    }
+
+    public void setArea(Area area) {
+        this.area = area;
+    }
+
+    public Date getCreatedAt() {
+        return createdAt;
+    }
+
+    public void setCreatedAt(Date createdAt) {
+        this.createdAt = createdAt;
+    }
+
+    public UUID getId() {
+        return id;
+    }
+
+    public void setId(UUID id) {
+        this.id = id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getContent() {
+        return content;
+    }
+
+    public void setContent(String content) {
+        this.content = content;
+    }
+}

json-modules/json-2/src/main/java/com/baeldung/jsonschemageneration/simple/SimpleSchemaGenerator.java

@@ -0,0 +1,23 @@
+package com.baeldung.jsonschemageneration.simple;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.github.victools.jsonschema.generator.Option;
+import com.github.victools.jsonschema.generator.OptionPreset;
+import com.github.victools.jsonschema.generator.SchemaGenerator;
+import com.github.victools.jsonschema.generator.SchemaGeneratorConfig;
+import com.github.victools.jsonschema.generator.SchemaGeneratorConfigBuilder;
+import com.github.victools.jsonschema.generator.SchemaVersion;
+
+public class SimpleSchemaGenerator {
+    public static void main(String[] args) {
+
+        SchemaGeneratorConfigBuilder configBuilder = new SchemaGeneratorConfigBuilder(SchemaVersion.DRAFT_2020_12, OptionPreset.PLAIN_JSON);
+        SchemaGeneratorConfig config = configBuilder.with(Option.EXTRA_OPEN_API_FORMAT_VALUES).without(Option.FLATTENED_ENUMS_FROM_TOSTRING).build();
+
+        SchemaGenerator generator = new SchemaGenerator(config);
+        JsonNode jsonSchema = generator.generateSchema(Article.class);
+
+        System.out.println(jsonSchema.toPrettyString());
+    }
+
+}

json-modules/json-2/src/main/resources/schemas/com/baeldung/jsonschemageneration/plugin/Person.json

@@ -0,0 +1,54 @@
+{
+  "$defs" : {
+    "Address" : {
+      "type" : "object",
+      "properties" : {
+        "city" : {
+          "type" : "string"
+        },
+        "country" : {
+          "type" : "string"
+        },
+        "street" : {
+          "type" : [ "string", "null" ]
+        }
+      },
+      "required" : [ "city", "country" ],
+      "additionalProperties" : false
+    }
+  },
+  "type" : "object",
+  "properties" : {
+    "address" : {
+      "$ref" : "#/$defs/Address"
+    },
+    "createdAt" : {
+      "type" : "string",
+      "readOnly" : true
+    },
+    "email" : {
+      "type" : "string",
+      "format" : "email",
+      "pattern" : "\\b[A-Za-z0-9._%+-]+@baeldung\\.com\\b"
+    },
+    "friends" : {
+      "maxItems" : 10,
+      "type" : "array",
+      "items" : {
+        "$ref" : "#"
+      }
+    },
+    "id" : {
+      "type" : "string",
+      "readOnly" : true
+    },
+    "name" : {
+      "type" : "string"
+    },
+    "surname" : {
+      "type" : "string"
+    }
+  },
+  "required" : [ "address", "email", "id", "name", "surname" ],
+  "additionalProperties" : false
+}