metrics_influxdb.Influxdb Maven / Gradle / Ivy

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//	metrics-influxdb 
//	
//	Written in 2014 by David Bernard  
//	
//	[other author/contributor lines as appropriate] 
//	
//	To the extent possible under law, the author(s) have dedicated all copyright and
//	related and neighboring rights to this software to the public domain worldwide.
//	This software is distributed without any warranty. 
//	
//	You should have received a copy of the CC0 Public Domain Dedication along with
//	this software. If not, see . 
package metrics_influxdb;

import java.io.IOException;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.nio.charset.Charset;
import java.util.concurrent.TimeUnit;

/**
 * A client to send data to a InfluxDB server via HTTP protocol.
 * 
 * The usage :
 * 
 *  *   Influxdb influxdb = new Influxdb(...);
 * 
 *   influxdb.appendSeries(...);
 *   ...
 *   influxdb.appendSeries(...);
 *   influxdb.sendRequest();
 *   
 *   influxdb.appendSeries(...);
 *   ...
 *   influxdb.appendSeries(...);
 *   influxdb.sendRequest();
 * 
 * 
 */
public class Influxdb {
  private static final Charset UTF_8 = Charset.forName("UTF-8");

  public static char toTimePrecision(TimeUnit t) {
    switch (t) {
    case SECONDS:
      return 's';
    case MILLISECONDS:
      return 'm';
    case MICROSECONDS:
      return 'u';
    default:
      throw new IllegalArgumentException("time precision should be SECONDS or MILLISECONDS or MICROSECONDS");
    }
  }

  public final URL url;
  private final StringBuilder json = new StringBuilder();
  /** true => to print Json on System.err */
  public boolean debugJson = false;

  public Influxdb(String host, int port, String database, String username, String password, TimeUnit timePrecision) throws Exception {
    this(new URL("http", host, port, "/db/" + database + "/series?u=" + URLEncoder.encode(username, UTF_8.name()) + "&p=" + password + "&time_precision=" + toTimePrecision(timePrecision)));
  }

  public Influxdb(URL url) throws Exception {
    this.url = url;
    resetRequest();
  }

  /**
   * Forgot previously appendSeries.
   */
  public void resetRequest() {
    json.setLength(0);
    json.append('[');
  }

  /**
   * Append series of data into the next Request to send.
   * 
   * @param namePrefix
   * @param name
   * @param nameSuffix
   * @param columns
   * @param points
   */
  public void appendSeries(String namePrefix, String name, String nameSuffix, String[] columns, Object[][] points) {
    if (json.length() > 1)
      json.append(',');
    json.append("{\"name\":\"").append(namePrefix).append(name).append(nameSuffix).append("\",\"columns\":[");
    for (int i = 0; i < columns.length; i++) {
      if (i > 0)
        json.append(',');
      json.append('"').append(columns[i]).append('"');
    }
    json.append("],\"points\":[");
    for (int i = 0; i < points.length; i++) {
      if (i > 0)
        json.append(',');
      Object[] row = points[i];
      json.append('[');
      for (int j = 0; j < row.length; j++) {
        if (j > 0)
          json.append(',');
        Object value = row[j];
        if (value instanceof String) {
          json.append('"').append(value).append('"');
        } else {
          json.append(value);
        }
      }
      json.append(']');
    }
    json.append("]}");
  }

  public int sendRequest(boolean throwExc, boolean printJson) throws Exception {
    int lg = json.length();
    try {
      json.append(']');
      // byte[] content = URLEncoder.encode(json.toString(),
      // "UTF-8").getBytes(UTF_8);
      byte[] content = json.toString().getBytes(UTF_8);
      if (printJson || debugJson) {
        System.err.println("----");
        System.err.println(json);
        System.err.println("----");
      }

      HttpURLConnection con = (HttpURLConnection) url.openConnection();

      con.setRequestMethod("POST");
      // con.setRequestProperty("User-Agent", "InfluxDB-jvm");

      // Send post request
      con.setDoOutput(true);
      OutputStream wr = con.getOutputStream();
      wr.write(content);
      wr.flush();
      wr.close();

      int responseCode = con.getResponseCode();
      if (responseCode == HttpURLConnection.HTTP_OK) {
        // ignore Response content
        con.getInputStream().close();
        resetRequest();
      } else if (throwExc) {
        throw new IOException("Server returned HTTP response code: " + responseCode + "for URL: " + url + " with content :'" + con.getResponseMessage() + "'");
      }
      return responseCode;
    } catch (Exception exc) {
      json.setLength(lg);
      throw exc;
    }
  }
}