How to autowire RestTemplate by default

2588

Currently, I am creating a RestTemplate object every time like below.

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);
	}
}

Instead of creating RestTemplate for every service, how to auto wire ResTemplate?

1 Answer

5 years ago by

You can create RestTemplate and return and make return object to register with spring IoC by using @Bean.

package com.example.demo;

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

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.context.annotation.Bean;
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 {

	@Autowired
	private RestTemplate restTemplate;


	@Bean
	private RestTemplate createRestTemplate(RestTemplateBuilder restTemplateBuilder) {
		RestTemplate restTemplate = restTemplateBuilder.build();
		List<HttpMessageConverter<?>> messageConverters = new ArrayList<>();
		MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
		converter.setSupportedMediaTypes(Collections.singletonList(MediaType.ALL));
		messageConverters.add(converter);
		return restTemplate;
	}

	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);
	}
}
5 years ago by Anil