JAVA POJO Class Generate with jsonSchemaUrl Annotation

json-schema-pojo is a library that automatically generate JAVA POJO class file on compile time. (like lombok library)

Just add maven repository dependency,

    <dependency>
        <groupId>com.github.whsoul</groupId>
        <artifactId>json-schema-pojo</artifactId>
        <version>X.Y.Z</version>
    </dependency>

and make config class With Annotations,

then Java compiler make POJOs along annotation configs.

Base Use

public class ConfigClass {

    @JsonSchemaPojo(packageName = "com.test.pojo"
                    , className = "Datas"
                    , schemaUrl = "https://whsoul.github.io/json-schema-pojo/test-schema01.json")
    public String fromExternalResource;

    @JsonSchemaPojo(packageName = "com.test.pojo2"
                    , className = "Sample"
                    , schemaUrl = "sample_schema_01.json")
    public String fromOwnResource;

there are 2 kind of options with target schema

internet resource reference ( offline mode, not available )

https://whsoul.github.io/json-schema-pojo/test-schema01.json

my own(or downloaded) schema ( under src/main/resources )

sample_schema_01.json

And also you can inject custom configurations, such as below

Base Config Enable/Disable

    @JsonSchemaPojo(packageName = "com.test.sample1", className = "Student"
                    , schemaUrl = "sample_schema_01.json"
                    , baseConfig = {
                        @JsonSchemaPojo.BaseConfig(
                                feature = JSONSCHEMA_POJO_FEATURE.STRING_ENUM_AS_ENUM
                                ,enable = true
                        )
                    })
    public String enableDisableBaseConfig;

Control library generate default actions with config enable/disable

Customize Type Mapping

    @JsonSchemaPojo(packageName = "com.test.sample1", className = "Student"
                    , schemaUrl = "sample_schema_01.json"
                    , typeMappingConfig = {
                        @JsonSchemaPojo.TypeMappingConfig(
                                typeName = "string"
                                , typeJavaClass = MyString.class
                        ),
                        @JsonSchemaPojo.TypeMappingConfig(
                                typeName = "integer"
                                , typeJavaClass = int.class
                        ),
                        @JsonSchemaPojo.TypeMappingConfig(
                                typeName = "customFloat"
                                , typeJavaClass = float.class
                        )
                    }
    )
    public String sampleClass1;

Standard json schema specification support only simpleTypes below

type	default mapping
string	String.class
boolean	boolean.class
long	long.class
integer	Integer.class
number	Double.class
array	List.class
object	Map.class
null	Void.class

but customType supported. override default mapping also

Customize Validation Annotation Config

    @JsonSchemaPojo(packageName = "com.test.sample1", className = "Student"
                    , schemaUrl = "sample_schema_01.json"
                    , annotationConfig = {
                        @JsonSchemaPojo.AnnotationConfig(
                                type = ANNOTATION_TYPE.FIELD_REQUIRED
                                , annotationClass = MyNotNull.class
                        )
                    }
    )
    public String sampleClass1;

Add Interface, Superclass with

    @JsonSchemaPojo(packageName = "com.test.sample1", className = "Student"
                    , schemaUrl = "sample_schema_01.json"
                    ,superclassConfig = {
                        @JsonSchemaPojo.SuperConfig(
                                superclass = A.class
                                , targetClassNames = "com.test.sample1.Student" +
                                                     ",com.test.sample1.definitions.University" +
                                                     ",com.test.sample1.definitions.University.Location"
                        )
                    }
                    ,superinterfaceConfig = {
                        @JsonSchemaPojo.SuperConfig(
                                superclass = BInterface.class
                                , targetClassNames = "com.test.sample1.Student" +
                                ",com.test.sample1.definitions.University" +
                                ", com.test.sample1.definitions.University.Location "
                        )
                    }
    )
    public String sampleClass1;

if you want to add superclass or interface to generated classes, you can use superclassConfig, superinterfaceConfig

Usage Example

API Specifications exchange for caller(client with java)

Java base (Client - Server), (Server - Server) easily exchanges Request, Response data format.

API Server Application

Develop Java API Application with json Request, Response
Generate jsonSchema file (Request Model, Response Model)
Create automatically generate with 3rd party POJO to Json schema library below Reference(#1) ( or Create jsonSchema Structure by your self)
Deploy the static files with your API Server application, or other static CDN (example] http://your.application.domain/my-api001-REQUEST-schema.json, ... my-api001-RESPONSE-schema.json )
Let client know your Server API url with and the schema file download URL

Java Client

Add this library at pom or gradle
Add @JsonSchemaPojo in your code, and schema download url

    @JsonSchemaPojo(packageName = "com.test.pojo"
                    , className = "Api001RequestPojo"
                    , schemaUrl = "http://your.application.domain/my-api001-REQUEST-schema.json")
    public String yourApi001Request;

whsoul/json-schema-pojo