MapItClientService.java

/**
 * @author ishaikh
 *
 */
package com.transformuk.bdt.service;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Component;
import org.springframework.web.client.RestTemplate;

import com.google.common.util.concurrent.RateLimiter;

@Component
public class MapItClientService {

	// allow a max of 1 call per second i.e. 180 per 3 mins
	private static final int NO_OF_PERMITS_PER_SECOND = 1;

	@Autowired
	MapItMongoService mapItMongoService;

	// final
	final RateLimiter limiter = RateLimiter.create(NO_OF_PERMITS_PER_SECOND);

	@Autowired
	RestTemplate restTemplate;

	public ResponseEntity<String> callMapIt(String mapItUrl, String postCode) {

		// wait until we acquire
		limiter.acquire();

		try {

			return restTemplate.exchange(mapItUrl, HttpMethod.GET,
					buildHeader(), String.class, postCode);
		} finally {
			mapItMongoService.updateCount();
		}

	}

	public ResponseEntity<String> callMapIt(String mapItUrl) {

		// wait until we acquire
		limiter.acquire();

		try {
			return restTemplate.exchange(mapItUrl, HttpMethod.GET,
					buildHeader(), String.class);
		} finally {
			mapItMongoService.updateCount();
		}
	}

	private HttpEntity<String> buildHeader() {
		HttpHeaders headers = new HttpHeaders();
		headers.set("User-Agent", "Department of Business, Innovation & Skills");
		return new HttpEntity<String>("parameters", headers);
	}

}