Categories

  • java

Tags

  • graphql
  • java

Enhancing GraphQL APIs with GraphQL SPQR and Servlet Integration

GraphQL SPQR is a powerful library for creating flexible and powerful rest based API. GraphQL SPQR, in combination with Spring Boot, has become a go-to choice for building GraphQL APIs in the Java world. While GraphQL SPQR simplifies API development from Java projects, there are situations where you need to customize the behavior of your API even further.

SPQR annotation directly allows us to access HTTP methods(GET/POST/DELETE/POST) and content but some times that’s not enough and we need servelet object access to sprint API to customize actions such as

  • Access all headers
  • Populate new headers
  • Access html Body content
  • Custom renedering to Rest API handlers.

Let’s take a look at a code snippet that shows how to access the native ServletRequest object and populate headers based on a condition:

//GraphQL SPQR resolver
@Component
@GraphQLApi
public class SampleResolver{
    @GraphQLQuery
    public String helloworld(@GraphQLEnvironment ResolutionEnvironment env, 
@GraphQLArgument(name = "name") String name){

//If name is empty then set no data content HTTP Header   
if(name.equals("")){
    //GraphQL Global context
        DefaultGlobalContext dgc = env.dataFetchEnvironment().getContext();
       ServletWebRequest request = (ServletWebRequest) dgc.getNativeRequest();
      
       request.getResponse().setHeader(HttpStatus.NO_CONTENT.value()+"",HttpStatus.NO_CONTENT.getReasonPhrase());
        return ""; 
    }        
     return String.format("Hello: %s",name);    
        
    }
}

In conclusion, the code snippet you have direct access to the HttpServletRequest object, allowing us to manipulate headers and perform custom actions based on specific conditions giving you greater flexibility and control over your GraphQL API.

References