upo-senior-assistant-pi/src/main/java/support/Rest.java

package support;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import com.google.gson.Gson;

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPut;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Una classe generica che invia delle richieste Rest e le parsifica nel JSON corrispondente
 */
public class Rest {

    /**
     * Un logger per vedere quando le richieste falliscono
     */
    private static final Logger LOG = LoggerFactory.getLogger("Rest");

    /**
     * Un GSON utile per il parsing della risposta
     */
    private static final Gson gson = new Gson();

    /**
     * Perform a GET request towards a server
     *
     * @param URL the @link{URL} to call
     * @return the response, parsed from JSON
     */
    public static Map<String, ?> get(String URL) {
        Map<String, ?> response = new HashMap<>();

        try {
            CloseableHttpClient httpclient = HttpClients.createDefault();
            HttpGet request = new HttpGet(URL);
            CloseableHttpResponse result = httpclient.execute(request);
            String json = EntityUtils.toString(result.getEntity());

            response = gson.fromJson(json, Map.class);
            result.close();

            httpclient.close();
            LOG.debug("GET response: " + json);
        } catch (Exception e) {
            LOG.error("GET: " + e.getMessage());
        }


        return response;
    }

    /**
     * Perform a PUT request towards a server
     *
     * @param URL         the @link{URL} to call
     * @param contentBody the content body of the request
     * @param contentType the content type of the request
     */
    public static void put(String URL, String contentBody, String contentType) {
        try {
            CloseableHttpClient httpclient = HttpClients.createDefault();
            HttpPut request = new HttpPut(URL);
            StringEntity params = new StringEntity(contentBody);

            request.addHeader("content-type", contentType);
            request.setEntity(params);

            HttpResponse result = httpclient.execute(request);

            httpclient.close();
        } catch (Exception e) {
            LOG.error("PUT: " + e.getMessage());
        }
    }

}