如何从javaspring启动应用程序调用GraphQLapi？是否有支持graphQL查询格式的注释？

Question

我正在寻找一个解决方案来实现来自Spring-引导应用程序的GraphQL api调用，查询模式如下：

查询{

getDetailsByRefNumber（RefNumbers： “”）

{

field1,

field2,

field3 

} }

有人知道如何实现这一点吗？通过以下链接之一，但未找到任何解决方案

有没有基于java的Graphql客户端可以从Java代码调用graphql服务器？

Answer 1

您可以使用可在以下位置获得的“图形ql-webclient-sping-boot-starter”库：

https://github . com/graph QL-Java-kickstart/graph QL-spring-webclient

<!-- https://mvnrepository.com/artifact/com.graphql-java-kickstart/graphql-webclient-spring-boot-starter -->
<dependency>
  <groupId>com.graphql-java-kickstart</groupId>
  <artifactId>graphql-webclient-spring-boot-starter</artifactId>
  <version>1.0.0</version>
</dependency>

示例实现可以是这样的：

假设你有 MyEntity 对象：

public class MyEntity
{
    String field1;
    String field2;
    String field3;
    //getter and setters here
}

您还在“src/main/资源”文件夹下有两个图形ql查询文件：

query1.graphql：

#query1.graphql
#this query returns a list of some_detail_entity
query getDetailListByRefNumber($RefNumber: String!){
    some_detail_entity(where: {RefNumber : { _eq: $RefNumber } }) {
        field1
        field2
        field3 
    } 
}

query2.graphql:

#query2.graphql
#this query returns a single some_detail_entity
query getDetailByRefNumber($RefNumber: String!){
    some_detail_entity_by_pk(RefNumber : $RefNumber) {
        field1
        field2
        field3 
    } 
}

您可以使用此代码段调用 graphql 服务器进行查询

ObjectMapper objectMapper = new ObjectMapper();

WebClient webClient = WebClient.builder()
.baseUrl("https://endpoint-url-of-graphql.com")//url of graphql instance
.defaultHeader("auth-token", "some-cryptic-code-if-required")//if auth header not required, just delete this line
.build();

GraphQLWebClient graphqlClient = GraphQLWebClient.newInstance(webClient, objectMapper);

//if expecting a single entity (not array)
MyObject entity = graphqlClient.post("query2.graphql", 
Map.of("RefNumber", "A7EED900-9BB4-486F-9F7C-2136E61E2278"), MyEntity.class)
            .block();   

            
//if expecting a list of entity (array)
var response = graphqlClient.post(GraphQLRequest.builder().resource("query1.graphql")
        .variables(Map.of("RefNumber", "A7EED900-9BB4-486F-9F7C-2136E61E2278")).build())
                .block();   

List<MyEntity> entityList = response.getFirstList(MyEntity.class);