问java中两个GraphQL api之间的通信

EN

query getBook($isbn:String!){
    book1:getBook(isbn:$isbn){
     title
    } 
}

dependency>
       <groupId>com.apollographql.apollo</groupId>
       <artifactId>apollo-runtime</artifactId>
       <version>2.2.0</version>
   </dependency>

<plugin>
    <groupId>com.github.sparow199</groupId>
    <artifactId>apollo-client-maven-plugin</artifactId>
    <version>3.2.0</version>
    <executions>
        <execution>
            <goals>
                <goal>generate</goal>
            </goals>
            <configuration>
                    <rootPackageName>com.example.graphqlAPI</rootPackageName>
            </configuration>
        </execution>
    </executions>
</plugin>

package com.example.graphqlAPI.Controller;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import com.apollographql.apollo.ApolloCall.Callback;
import com.apollographql.apollo.ApolloClient;
import com.apollographql.apollo.api.Response;
import com.apollographql.apollo.exception.ApolloException;
import com.example.graphqlAPI.GetBookQuery;

import okhttp3.OkHttpClient;

@RestController
@RequestMapping("/api")
public class ApolloClientController {
    

    private static final int TIMEOUT = 5000;

     private static final org.slf4j.Logger LOGGER = LoggerFactory.getLogger(ApolloClientController.class);
     
        @GetMapping("/prod") 
  public Map<String,Object> processApi(@RequestParam (required = false) String isbn ){
        
        
            Map<String,Object> hm = new HashMap<String, Object>();
        OkHttpClient okHTTPCLIENT = new OkHttpClient.Builder().build();
        
        ApolloClient client = ApolloClient.builder().serverUrl("http://localhost:8080/graphql")
                .okHttpClient(okHTTPCLIENT).build();

        CountDownLatch lock = new CountDownLatch(1);
        
        client.query(GetBookQuery.builder().isbn(isbn).build()).enqueue(new Callback() {

            @Override
            public void onResponse(Response response) {
                // TODO Auto-generated method stub
                
                LOGGER.info("Res: {}", response.getData());
                hm.put("Response", response.getData());
                lock.countDown();
                
            }

            @Override
            public void onFailure(ApolloException e) {
                // TODO Auto-generated method stub
                 LOGGER.info("Err: {}", e);
                lock.countDown();
                hm.put("Error", "Error while fetchiing the data");
            }
        
        });
        try {
            lock.await(TIMEOUT, TimeUnit.MILLISECONDS);
        } catch (InterruptedException e1) {
            // TODO Auto-generated catch block
        e1.printStackTrace();
        }
        return hm;
    }

}