GraphQLSchemaGenerator is a light-weight java component which converts Java DTO classes into graphQL schema. GraphQLSchemaGenerator uses ClassPathScanningCandidateComponentProvider to find the components which are involved in schema generation process.

The primary need for creating GraphQLSchemaGenerator is there is no proper library/framework for java based server applications to map java dto classes and graphQL schema.

Sample

GraphQlSchemaGenerator graphQlSchemaGenerator = new GraphQlSchemaGenerator();
graphQlSchemaGenerator.generatedSchema("com.yogaraj.graphql.dto");
String schema = graphQlSchemaGenerator.getSchema();

GraphQLSchemaGenerator uses specific annotations to identify and build graphQL schemas, Below are the annotation which are employed in schema generation process.

@GraphQLSchema : Indicates the particular class is involved in GraphQL schema creation process.

@GraphQLSchema(schemaType = SchemaType.OBJECT, operationName = "doc")
public  class  Doc {}

@GraphQLField : Indicates the particular class variable is considered as GraphQL schema feild.

@GraphQLSchema(schemaType = SchemaType.OBJECT, operationName = "doc")
public  class  Doc {

@GraphQLField
public  String  title;

@GraphQLField(isNullable = false)
public  String  url;
}

Sample Output

 type doc {
	title: String
	url: String!
}

 enum docType {
	media
	document
}

Supported GraphQL Features

1. Fields

2. parametes, multi-param

3. Aliases

4. operation name

5. query, mutation,input

6. not null

7. enum

8. interface and implementation

9. unions

10. extend

Features under work

1. scalars

2. directives