java - 如何在 Spring Boot + GraphQL Java 工具上下文中执行对 GraphQL 的 Java 调用？

Question

在 Spring Boot 应用程序中，我们已经拥有一个功能齐全的 GraphQL 端点，通过 GraphQL Java 工具提供 .graphqls 文件(我们包含 graphql-spring-boot-starter 依赖项)，并通过实现 GraphQLQueryResolver 和后续 GraphQLResolver 的基本 Query 类处理数据解析。

出于业务需求，我们必须重新创建标准 REST API 端点，所以我想知道为什么不直接调用 GraphQL(而不是再次“手动”重新实现数据解析)？由于它位于同一个后端应用程序中，因此无需进行 HTTP 或 servlet (ForwardRequest) 调用，只需调用 Java 中的一些 API 即可。问题是我不知道如何继续。

我读过这个示例，但它是使用基本的 GraphQL Java(不是工具): https://www.graphql-java.com/documentation/v9/execution/

我知道这应该是可能的，因为我们可以在测试中这样做: https://github.com/graphql-java-kickstart/graphql-spring-boot/blob/master/example-graphql-tools/src/test/java/com/graphql/sample/boot/GraphQLToolsSampleApplicationTest.java

但是如何在常规代码中做到这一点呢？不存在 GraphQLTemplate 这样的东西。

我还尝试在以下位置搜索示例:

• https://github.com/graphql-java-kickstart/graphql-java-tools/tree/master/example
• https://github.com/graphql-java-kickstart/graphql-spring-boot

但没有发现任何与我们的需求相关的内容。

在文档中找不到更多内容:

• https://www.graphql-java-kickstart.com/tools/
• https://www.graphql-java-kickstart.com/spring-boot/

我错过了什么？理想情况下，我希望注入(inject)一些 GraphQLSomething，如下所示:

@RestController
@RequestMapping(path = "api")
public class CompanyController {

    @Autowired
    private GraphQLSomething graphQLSomething;

    @GetMapping("company/{id}")
    public ResponseEntity<?> societe(@PathVariable @NotNull Integer id) {
        GraphQLSomethingResult result = GraphQLSomething.query("company(id: $id) { id name andsoone }", "{ \"id\": 123456 }").execute(); // not really sure of the GraphQL syntax here, but it'll need some tests...
        return result.getDataOrElse();
    }

}

Answer 1

终于找到了如何做我想要的事情:

import java.util.Map;
import java.util.Optional;

import javax.validation.constraints.NotNull;
import javax.validation.constraints.Positive;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.google.common.collect.ImmutableMap;

import graphql.ExecutionResult;
import graphql.servlet.core.GraphQLQueryInvoker;
import graphql.servlet.core.internal.GraphQLRequest;
import graphql.servlet.input.GraphQLInvocationInputFactory;
import graphql.servlet.input.GraphQLSingleInvocationInput;
import lombok.extern.slf4j.Slf4j;

@Slf4j
@Validated
@RestController
@RequestMapping(path = "api")
public class CompanyController {

    @Autowired
    private GraphQLInvocationInputFactory invocationInputFactory;

    @Autowired
    private GraphQLQueryInvoker queryInvoker;

    @GetMapping("company/{id}")
    public ResponseEntity<?> societe(@PathVariable @NotNull Integer id) {
        String query = "query ($id: Int!) { company(id: $id) { id name andsoon } }";
        /*
         * ImmutableMap is a Guava class; you can build the map (e.g. a HashMap) on your
         * own, or simply Map.to(..) in Java 9, or even @PathVariable Map<String,
         * Object> variables as the method's parameter instead (but you'll miss the
         * validation).
         */
        Map<String, Object> variables = ImmutableMap.of("id", id);

        GraphQLRequest request = new GraphQLRequest(query, variables, null);
        GraphQLSingleInvocationInput invocationInput = invocationInputFactory.create(request);
        ExecutionResult result = queryInvoker.query(invocationInput);

        /*
         * Of course result.getData() can be null here - see also result.isDataPresent()
         * - but data/error handling's left to you
         */
        Optional<Object> company = Optional.ofNullable(result.getData().get("company"));
        return ResponseEntity.of(company);
    }

}