Graphql Java Annotations framework introduction and use tutorial

Graphql Java Annotations is a Java library used to build Graphql API. It provides a set of annotations to define GraphQL mode and parser.By using these annotations, developers can easily expose the existing Java classes and methods into GraphQL types and fields. The following are the basic steps of using Graphql Java Annotations: Step 1: Add dependencies First, add Graphql Java Annotations library to your Java project.You can implement it by building tools such as Maven or Gradle.For example, for the Maven project, the following dependencies can be added to the pom.xml file: <dependency> <groupId>com.graphql-java-kickstart</groupId> <artifactId>graphql-java-annotations</artifactId> <version>7.2.1</version> </dependency> Step 2: Define the Graphql type By using annotations on the Java class, you can define this class as GraphQL type.For example, assuming that there is a Person class, you can use the `@Graphqlobject` annotation to mark it as the Graphql object type, and use the`@Graphqlfield` annotation to expose its field to the GraphQL field. @GraphQLObject public class Person { @GraphQLField private String name; // Getters and setters } Step 3: Define Graphql query By creating a method that contains the annotation of `@grageqlquery`, you can define the Graphql query.The return value of this method will be exposed to the field of the GraphQL interface. @GraphQLObject public class Query { @GraphQLQuery public Person getPersonById(String id) { // Logic to retrieve person by ID } } Step 4: Construct Graphql SCHEMA Using the static method of the `Graphqlannotations` class, you can build Graphql SChema based on the defined Graphql type and query.The SCHEMA defines the structure of your Graphql API. GraphQLSchema schema = GraphQLAnnotations.schema("com.example.package"); Step 5: Execute Graphql query Finally, you can use the Graphql Java library to perform the GraphQL query.Create a GraphQL actuator and use SCHEMA and query string to perform query. GraphQL graphql = GraphQL.newGraphQL(schema).build(); ExecutionResult result = graphql.execute("{ getPersonById(id: \"1\") { name } }"); Using Graphql Java Annotations Library, you can use annotations to define the Graphql mode and parser, which is more convenient and concise than manually writing Graphql Schema and analyzer code. I hope this article will be helpful to you so that you can understand and use Graphql Java Annotations framework.