Java - Philips Hue Bridge interaction class
In un articolo precedente, abbiamo parlato di cosa sono le lampade Philips Hue, e della praticità con il quale è possibile programmarle per creare un ambiente domotizzato relativamente a basso costo.
Il bridge è dotato di pratiche API RESTful, e la comunicazione avviene secondo lo standard JSON. Motivo per cui è facile realizzare una classe di comunicazione con una miriade di linguaggi di programmazione. Quella presentata in basso, è una classe per la comunicazione con il Bridge di philips, scritta in java, essa consta di soli 2 file:
File hue_json.java:
/*
* Interaction with Philips Hue Bridge.
*
* Before you start with encoding and decoding JSON using Java, you will need to install any of the JSON modules available.
* For this application I downloaded and installed JSON.simple and add the location of json-simple-1.1.1.jar file to environment variable CLASSPATH.
*
*/
package javaapplication1;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import org.json.simple.*; //lib json-simple-1.1.1.jar
import org.json.simple.parser.*;
public class hue_json {
private static String upnp = "http://www.meethue.com/api/nupnp"; // UPNP service to get automatically hue_bridge_ip in LAN.
private static String hue_bridge_ip = null;
private static String base_url = "/api/newdeveloper/"; // User autenticated on the bridge: /newdeveloper/
public hue_json(){ //constructor checks for hue bridge local ip address.
try{ // get Hue bridge local IP address if not specified
if (hue_bridge_ip == null){ //the ip address is not specified, we'll try to get it automatically
// try to get ip from meethue website.
String r = url_reader.address(upnp);
//System.out.println(r);
JSONParser parser = new JSONParser();
Object obj = parser.parse(r);
JSONArray array = (JSONArray) obj;
JSONObject obj2 = (JSONObject)array.get(0);
hue_bridge_ip = (obj2.get("internalipaddress")).toString();
//System.out.println(hue_bridge_ip);
}
}
catch (IndexOutOfBoundsException e){
System.out.println("Error fetching Bridge IP from Meethue.com UPNP service. Make sure the bridge is connected or "+upnp+" reachable"); //System.out.println(e);
System.exit(1); // Terminate the application.
}catch (Exception e){
System.out.println("Generic Exception: "+e);
}
}
public hue_json(String ip){ // overloading to define manually hue bridge local ip address
hue_bridge_ip = ip;
}
public String getHueBridgeIp(){
System.out.println(hue_bridge_ip);
return hue_bridge_ip;
}
public String getUpnp(){
System.out.println(upnp);
return upnp;
}
public String getBaseUrl(){
System.out.println(base_url);
return base_url;
}
public void setBridgeIp(String z){ // set different ip address for the bridge
hue_bridge_ip = z;
}
private static Object getLightProperty(String property_name, Integer n_luce) throws Exception{ // retrieve the value of specified property name.
try{
String r = url_reader.address("http://"+hue_bridge_ip+base_url+"lights/"+n_luce+"/");
//System.out.println(r);
JSONParser parser = new JSONParser();
Object obj = parser.parse(r);
JSONObject state = (JSONObject) obj;
JSONObject on = (JSONObject) state.get("state");
return on.get(property_name);
}
catch (ClassCastException e){
System.out.println("Bulb number "+n_luce+" not registered... Bad request!");
System.exit(1); // Terminate the application.
return false;
}
}
public boolean getLightState(Integer n_luce) throws Exception{
return (boolean) getLightProperty("on", n_luce);
}
public Long getLightHue(Integer n_luce) throws Exception{
return (Long) getLightProperty("hue", n_luce);
}
public Long getLightBrightness(Integer n_luce) throws Exception{
return (Long) getLightProperty("bri", n_luce);
}
public Long getLightSaturation(Integer n_luce) throws Exception{
return (Long) getLightProperty("sat", n_luce);
}
public static int setLightProperty(Integer n_luce, String prop, Object x) throws Exception{
URL url;
if (n_luce == 0){ url = new URL("http://"+hue_bridge_ip+base_url+"groups/0/action/");}
else{
url = new URL("http://"+hue_bridge_ip+base_url+"lights/"+n_luce+"/state/");
}
try{
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("PUT"); //Because Hue Bridge RESTful API need PUT request to process a cmd.
connection.setDoOutput(true);
connection.setRequestProperty("Content-Type", "application/json");
connection.setRequestProperty("Accept", "application/json");
OutputStreamWriter osw = new OutputStreamWriter(connection.getOutputStream());
JSONObject payload = new JSONObject();
/* // data types:
payload.put("name", "foo");
payload.put("num", new Integer(100));
payload.put("balance", new Double(1000.21));
payload.put("is_vip", new Boolean(true));
*/
payload.put(prop, x);
//System.out.print(payload);
osw.write(payload.toString());
osw.flush();
osw.close();
return connection.getResponseCode(); // 200 - OK (Good response)
}catch (java.net.UnknownHostException e){
System.out.println("Impossibile connettersi al bridge HUE locale!");
return -1;
}catch (Exception e){
System.out.println("Eccezione generica: "+ e);
return -1;
}
}
public void setLightState(Integer n_luce, boolean val) throws Exception{
setLightProperty(n_luce, "on", val);
}
public void setLightHue(Integer n_luce, Integer val) throws Exception{
setLightProperty(n_luce, "hue", val);
}
public void setLightSaturation(Integer n_luce, Integer val) throws Exception{
setLightProperty(n_luce, "sat", val);
}
public void setLightBrightness(Integer n_luce, Integer val) throws Exception{
setLightProperty(n_luce, "bri", val);
}
public void setLightEffectOn(Integer n_luce) throws Exception{
setLightProperty(n_luce, "effect", "colorloop");
}
public void setLightEffectOff(Integer n_luce) throws Exception{
setLightProperty(n_luce, "effect", "none");
}
public void all_off() throws Exception{ // to turn off all the light we can call the method all_off() or directly turn_light(0, false);
setLightState(0, false); //light 0 means all the lights in the system. (better, the groups 0 contains all the lights registered on the bridge)
}
public void all_on() throws Exception{ // to turn on all the light we can call the method all_on() or directly turn_light(0, true);
setLightState(0, true); //light 0 means all the lights in the system.
}
public static void main(String[] args) throws Exception {
hue_json HUE = new hue_json(); // If not specified, the constructor will automatically find the hue bridge local ip address.
// hue_json HUE = new hue_json("192.168.1.3"); // Manually insert of hue bridge ip.
/*
System.out.println(HUE.getLightState(3));
System.out.println(HUE.getLightBrightness(3));
System.out.println(HUE.getLightSaturation(3));
System.out.println(HUE.getLightHue(3));
HUE.all_off();
HUE.all_on();
HUE.setLightState(3, true);
HUE.setLightHue(3, 15000);
HUE.setLightSaturation(3, 100);
HUE.setLightBrightness(3, 192);
HUE.setLightEffectOn(3);
HUE.setLightEffectOff(3);
*/
HUE.setLightEffectOff(1);
}
}
NB. Per operare con dati JSON viene usata la libreria JSON.simple.
File url_reader.java:
/*
* This file reads content from web page. Modified to work with hue_json.java
*/
package javaapplication1;
import java.net.*;
import java.io.*;
public class url_reader {
public static String address(String x){ // Example of use: url_reader.address("https://hackerstribe.com");
String nextLine;
URL url;
URLConnection urlConn;
InputStreamReader inStream;
BufferedReader buff;
try{
// Create the URL obect that points
// at the default file index.html
url = new URL(x);
urlConn = url.openConnection();
inStream = new InputStreamReader(
urlConn.getInputStream());
buff= new BufferedReader(inStream);
// Read and print just the first line, to read further lines, we need to put a while(true) construct.
nextLine =buff.readLine();
if (nextLine !=null){
return nextLine;
}
return null;
} catch(MalformedURLException e){
System.out.println("Please check the URL:" +
e.toString() );
} catch(IOException e1){
System.out.println("Can't read from the Internet: "+
e1.toString() );
}
return null;
}
}
