RestTemplate set Headers


How to set headers to RestTemplate

  • RestTemplate we need to use exchange() for a service call.
  • exchange() will accepts url, method, requestEntity, responseType as arguments.
java restTemplate.exchange(url, method, requestEntity, responseType)
  • method is HttpMethod with GET, POST ...
  • requestEntity is for body and headers of service request.
  • HttpEntity will be used as requestEntity.
  • set headers to HttpEntity.
HttpHeaders headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
HttpEntity<String> entity = new HttpEntity<>(headers);

Service

package com.example.demo;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

@Service
public class UserService {

	private final RestTemplate restTemplate;

	public UserService(RestTemplateBuilder restTemplateBuilder) {
		this.restTemplate = restTemplateBuilder.build();
		List<HttpMessageConverter<?>> messageConverters = new ArrayList<>();
		MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
		converter.setSupportedMediaTypes(Collections.singletonList(MediaType.ALL));
		messageConverters.add(converter);
		this.restTemplate.setMessageConverters(messageConverters);
	}

	public Object getUser(int userId) {
		HttpHeaders headers = new HttpHeaders();
		headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
		HttpEntity<String> entity = new HttpEntity<>(headers);
		return this.restTemplate.exchange("https://jsonplaceholder.typicode.com/todos/" + userId, HttpMethod.GET,
				entity, Object.class);
	}
}