- Download the pubsub-java.jar file to your computer
- Create a new Java project
- Add a new folder in your Java project called libs
- Copy the downloaded jar file (see #1) into the new folder, project/libs
- Inside Eclipse, find the Package Explorer.
- Expand your Java project, so that the libs folder is opened.
- Right-click the pubsub-java.jar file and select Add to Buildpath
Connect
// Create the library object
mPubsub = new Pubsub();
// Add the listener (this is where your application will get responses from the server)
mPubsub.addPubsubListener(this);
// Connect to the server, it's important that you add the listener first!
mPubsub.connect("java");Subscribe
It's important that all subscription messages be sent in the onOpen method of the PubsubListener!
@Override
public void onOpen() {
JSONObject filter = new JSONObject();
JSONObject version = new JSONObject();
try {
version.put("$gt", 0.1);
filter.put("version", version);
} catch (JSONException e) {
e.printStackTrace();
}
// You need to give the filter a unique name (String) when subscribing, this is
// so the library can keep track of the different filters! You will get a unique
// integer in return. (You only need this if you want to unsubscribe at some point!)
subscription_all = mPubsub.subscribe(filter, "version");
}Publish
Don't publish before the server has connected (the onOpen method has been called)
JSONObject doc = new JSONObject();
try {
doc.put("version", 0.5);
} catch (JSONException e1) {
e1.printStackTrace();
}
mPubsub.publish(doc);Receive messages
All messages will be recieved in the onMessage method of the PubsubListener!
@Override
public void onMessage(int callback_id, JSONObject doc) {
if (callback_id == subscription_all){
try {
double version = doc.getDouble("version");
System.out.println("version:" + version);
} catch (JSONException e) {
e.printStackTrace();
}
}
mJTextArea.append("\n");
}