How to improve performance of RestTemplate

Question

I am writing a Spring Boot application and using RestTemplate to send out a request.

Here is my method:

import com.fasterxml.jackson.databind.JsonNode;
import org.springframework.web.client.RestTemplate;

public static JsonNode getResponse(URI uri)
        throws JsonParseException, JsonMappingException, IOException, URISyntaxException {

    RestTemplate restTemplate = new RestTemplate();

    return restTemplate.getForEntity(uri, JsonNode.class).getBody();

}

When I run the above method, it is taking roughly 3 seconds. When I run the same method in Postman, it is taking roughly 1 second.

What would account for this difference. Are there opportunities to improve the performance of RestTemplate?

Answer 1

First, declare restTemplate as a bean, instead of creating a new one every time.

@Bean
public RestTemplate restTemplate() {
    return new RestTemplate();
}

Second, try getting Object.class instead of JsonNode.class.

Third, try getForObject() if you don't need entity but the object itself.

Forth, give this a read. This is the library that spring uses behind the scenes for JSON serialization/deserialization.