### METHOD(S)

To `Signal a message` you can use the following method(s) in the Java V4 SDK:

```java
this.pubnub.signal().message(Object).channel(String);
```

| Parameter |    Type    | Required | Description |
| --------- | ---------- | -------- | ----------- |
| `message` |    `Object`  |   Yes    | The payload which will be serialized and sent. |
| `channel` |   `String`   |   Yes    | The channel which the signal will be sent to. |
| `sync` | `PNPublishResult` | No | Executes the call. Blocks the thread, exception is thrown if something goes wrong. |
| `async` | `PNCallback<PNPublishResult>` | No | Executes the call asynchronously. |

### BASIC USAGE

#### SIGNAL A MESSAGE TO A CHANNEL:

```java
pubnub.signal()
    .message("Hello everyone!")
    .channel("bar")
    .async(new PNCallback<PNPublishResult>() {
        @Override
        public void onResponse(PNPublishResult pnPublishResult, PNStatus pnStatus) {
            if (pnStatus.isError()) {
                Long timetoken = pnPublishResult.getTimetoken(); // signal message timetoken
            } else {
                pnStatus.getErrorData().getThrowable().printStackTrace();
            }
        }
    });
```

### RESPONSE

The `signal()` operation returns a `PNPublishResult` object which contains the following operations:

| Method           |    Type    | Description  |
| ---------------- | ---------- | ------------ |
| `getTimetoken()` |    Long    | Returns a long representation of the time token when the signal was published.|

### LISTENER

Signals arrive at the `signal()` method inside the PubNub's `SubscribeCallback` listener.

```java
pubnub.addListener(new SubscribeCallback() {

    // other callbacks omitted

    @Override
    public void signal(PubNub pubnub, PNSignalResult pnSignalResult) {
        System.out.println("Signal publisher: " + signal.getPublisher());
        System.out.println("Signal payload: " + signal.getMessage());
        System.out.println("Signal subscription: " + signal.getSubscription());
        System.out.println("Signal channel: " + signal.getChannel());
        System.out.println("Signal timetoken: " + signal.getTimetoken());
    }
});
```

## SUBSCRIBE RETURNS
The `subscribe()` operation returns a `PNSignalResult` for signals which contains the following operations:

| Method              | Type              | Description       |
| ------------------- | ----------------- | ----------------- |
| `getMessage()`      | `JsonElement`	  | The signal sent on the channel. |
| `getSubscription()` | `String`          | The channel group or wildcard subscription match (if exists). |
| `getChannel()`      | `String`          | The channel for which the signal belongs. |
| `getTimetoken()`    | `Long`            | Timetoken for the signal. |
| `getUserMetadata()` | `Object`          | User metadata. |