Graphql Java Annotations framework in the Java library

Graphql Java Annotions is a framework for creating and defining Graphql Schema in the Java library.This article will introduce how to use Graphql Java Annotations to define Graphql Schema and provide related programming code and configuration instructions. 1. Introduction to dependencies First of all, you need to add the following dependencies to the construction file of the Maven or Gradle project: Maven configuration: <dependency> <groupId>com.graphql-java</groupId> <artifactId>graphql-java-annotations</artifactId> <version>5.0.2</version> </dependency> Gradle configuration: groovy implementation 'com.graphql-java:graphql-java-annotations:5.0.2' Second, define Graphql SCHEMA Using Graphql Java Annotations, you can define the types, fields and queries in Graphql Schema through Java annotations. 1. Define the Graphql type A Graphql type can be defined by adding `@Graphqlfype` to the Java class.For example, the following code defines a Graphql type called `Book`, which contains two fields:` ID` and `Title`: @GraphQLType public class Book { @GraphQLField private String id; @GraphQLField private String title; // Getters and setters } 2. Define Graphql query By adding the `@Graphqlquery` annotation to the Java method, the Graphql query can be defined.The following example defines a query method called `GetbookByid`. This method receives a parameter` ID` and return a `Book` object: @GraphQLQuery(name = "getBookById") public Book getBookById(@GraphQLArgument(name = "id") String id) { // Find according to the ID and return to the Book object } 3. Construct Graphql SCHEMA Using Graphql Java Annotations' `schemaparser` class can build Graphql SChema from the defined type and query.The following is an example: GraphQLSchema schema = new SchemaParser().parse(Book.class); GraphQL graphql = GraphQL.newGraphQL(schema).build(); Third, execute Graphql query After completing the definition of Graphql SCHEMA, you can use the defined query method to perform the GraphQL query. 1. Create Graphql query string First, you need to create a GraphQL query string, specify the query to be executed and the corresponding parameters.For example, the following code creates a query string, calls `getBookbyid` query, and pass a parameter` ID`: String query = "{ getBookById(id: \"123\") { id, title } }"; 2. Execute Graphql query Using Graphql Java's `ExecutionInpput` and` ExecutionResult` classes can perform Graphql query and get results.The following is an example of executing Graphql query: ExecutionInput executionInput = ExecutionInput.newExecutionInput() .query(query) .build(); ExecutionResult executionResult = graphql.execute(executionInput); Map<String, Object> resultMap = executionResult.toSpecification(); After the execution is completed, the query results will be returned in the form of `Map <string, Object>`, which can be processed as needed. In summary, this article introduces how to use Graphql Java Annotations framework to define Graphql Schema in the Java class library, and demonstrates the relevant configuration and execution Graphql query through code examples.I hope to help you understand and use Graphql Java Annotations.