Java Http client simple

HttpClient.java

package http;


import java.io.*;
import java.net.HttpURLConnection;
import java.net.Proxy;
import java.net.URL;
import java.util.logging.Level;
import java.util.logging.Logger;
import moped.common.Utils;

public class HttpClient {

    public static final boolean VERBOSE_TRACE = true;

    public static final Logger log = Logger.getLogger(HttpClient.class.getCanonicalName());

    public static void callHttp(String payload, String url) {
        final StringBuilder outputString = new StringBuilder(1000);

        HttpURLConnection connection = null;
        try {
            connection = getConnection(url);
            if (connection == null) { throw new IllegalStateException("Cannot continue with no connection"); }

            try {
                final ByteArrayOutputStream bout = new ByteArrayOutputStream();

                final byte[] buffer = payload.getBytes();
                bout.write(buffer);
                final byte[] b = bout.toByteArray();

                // Set the appropriate HTTP parameters.
                connection.setRequestProperty("Content-Length", String.valueOf(b.length));
                connection.setRequestProperty("Content-Type", "Content-Type: application/json;charset=UTF-8");
                connection.setRequestMethod("POST");
                connection.setDoOutput(true);
                connection.setDoInput(true);
                final OutputStream out = connection.getOutputStream();
                //Write the content of the request to the outputstream of the HTTP Connection.
                out.write(b);
                out.close();
            } catch (IOException e) {
                log.log(Level.SEVERE, "Error connecting", e);

                try (final InputStream errorStream = connection.getErrorStream()) {
                    final String errMsg = Utils.readFully(errorStream);
                    log.log(Level.SEVERE, errMsg);
                } catch (IOException e1) {
                    log.log(Level.SEVERE, "Error reading error stream: ", e1);
                }

                return;

            }
            finally {
                if (VERBOSE_TRACE) log.info("Sucessfully send request");
            }

            String responseString;

            try (final InputStreamReader isr = new InputStreamReader(connection.getInputStream())) { // try to read the response.

                try (final BufferedReader in = new BufferedReader(isr)) {
                    while ((responseString = in.readLine()) != null) { 
                        outputString.append(responseString);
                    }
                }

            } catch (IOException e) {
                log.log(Level.SEVERE, "Error while sending ", e);

                try (final InputStream errorStream = connection.getErrorStream()) {
                    final String errMsg = Utils.readFully(errorStream);
                    log.log(Level.SEVERE, errMsg);
                } catch (IOException e1) {
                    log.log(Level.SEVERE, "Error reading error stream: ", e1);
                }

                return;
            }

            // TODO convert responseString to whatever you like

        }
        finally {
            if (connection != null) connection.disconnect();
        }

    }

    protected static HttpURLConnection getConnection(final String url) {
        try {
            final HttpURLConnection connection;
            if (VERBOSE_TRACE) log.info("Connecting to " + url);
            connection = (HttpURLConnection) new URL(url).openConnection(Proxy.NO_PROXY);
            if (VERBOSE_TRACE) log.info("Connected.");
            if (connection != null) return connection;
        } catch (Exception e) {
            log.log(Level.SEVERE, String.format("Error %s while connecting to : %s ", e.getMessage(), url), e);
        }

        throw new IllegalStateException("Could not connect!");

    }

}