Class Bluetooth

java.lang.Object
com.codename1.bluetooth.Bluetooth
Direct Known Subclasses:
HelperBluetooth
public class Bluetooth extends Object

Entry point for the Codename One Bluetooth API -- adapter state, runtime permissions and the capability queries that let cross-platform code branch cleanly. Obtain the platform implementation via getInstance(); the returned subclass is owned by the active port and never null.

The API is split by role:

  • com.codename1.bluetooth.le -- BLE central: scanning, connections and the GATT client, plus L2CAP channels.
  • com.codename1.bluetooth.le.server -- BLE peripheral: advertising and the local GATT server.
  • com.codename1.bluetooth.classic -- classic Bluetooth: discovery and RFCOMM stream connections (Android and the simulator only).
Quick start: check support and permissions
Bluetooth bt = Bluetooth.getInstance();
if (!bt.isLeSupported()) {
    // hide the feature
    return;
}
bt.requestPermissions(BluetoothPermission.SCAN, BluetoothPermission.CONNECT)
  .onResult((granted, err) -> {
       if (err == null && granted) {
           // start scanning...
       }
  });
Threading

Every callback of the Bluetooth API -- AsyncResource results, scan results, connection events, notifications, adapter state changes -- is delivered on the EDT. The only exceptions are the blocking InputStream/OutputStream pairs of RFCOMM and L2CAP connections, which must be consumed off the EDT.

Platform support
  • Android -- full stack: BLE central + peripheral, L2CAP (API 29+), classic RFCOMM. Permissions and manifest entries are auto-injected at build time when these packages are referenced.
  • iOS / Mac Catalyst -- CoreBluetooth: BLE central + peripheral and L2CAP. Classic RFCOMM is not exposed by iOS. The NSBluetooth* plist entries and CoreBluetooth framework are auto-injected at build time.
  • JavaSE simulator -- a scriptable virtual Bluetooth stack with a full feature matrix (Simulate -> Bluetooth Simulation), plus an optional native backend that talks to the host machine's real Bluetooth hardware (BLE central only).
  • JavaScript -- Web Bluetooth where the browser supports it: central role via the browser's device chooser, GATT client and notifications.
  • All other ports -- this base class is returned as-is and reports Bluetooth as unsupported; every operation fails fast with BluetoothError.NOT_SUPPORTED.

  • Constructor Details

    • Bluetooth

      protected Bluetooth()
      Ports construct subclasses. Application code obtains the active instance via getInstance().

  • Method Details

    • getInstance

      public static Bluetooth getInstance()
      Returns the platform-specific singleton owned by the current port. On ports that do not implement Bluetooth this returns a base Bluetooth instance that reports the feature as unsupported; calling code never needs a null check or a platform-specific if.

    • isSupported

      public boolean isSupported()
      true when this port/device exposes any Bluetooth functionality at all. Returns false on the fallback base class.

    • isLeSupported

      public boolean isLeSupported()
      true when the BLE central role (scanning, connections, GATT client) is available. Defaults to false.

    • isClassicSupported

      public boolean isClassicSupported()
      true when classic Bluetooth (discovery, RFCOMM) is available. Always false on iOS, which does not expose classic Bluetooth to apps. Defaults to false.

    • isPeripheralModeSupported

      public boolean isPeripheralModeSupported()
      true when the BLE peripheral role (advertising and a local GATT server) is available. false on tvOS/watchOS and on the JavaScript port. Defaults to false.

    • isL2capSupported

      public boolean isL2capSupported()
      true when L2CAP connection-oriented channels are available (Android 10+, iOS 11+). Defaults to false.

    • getAdapterState

      public AdapterState getAdapterState()
      The current state of the local adapter. The fallback base class reports AdapterState.UNSUPPORTED.

    • isEnabled

      public boolean isEnabled()
      Convenience for getAdapterState() == AdapterState.POWERED_ON.

    • addAdapterStateListener

      public void addAdapterStateListener(AdapterStateListener l)
      Registers a listener notified on the EDT whenever the adapter state changes. Listeners stay registered until removed via removeAdapterStateListener(AdapterStateListener).

    • removeAdapterStateListener

      public void removeAdapterStateListener(AdapterStateListener l)
      Removes a listener previously added via addAdapterStateListener(AdapterStateListener).

    • fireAdapterStateChanged

      protected final void fireAdapterStateChanged(AdapterState newState)
      Called by ports (from any thread) when the adapter transitions to a new state; dispatches to the registered listeners on the EDT.

    • requestEnable

      public AsyncResource<Boolean> requestEnable()
      Asks the user to enable the Bluetooth adapter where the platform supports it (the Android system dialog). Resolves true when the adapter was enabled, false when the user declined or the platform offers no programmatic enable flow (iOS, and this fallback base class). Never fails just because the feature is unsupported.

    • getLE

      public BluetoothLE getLE()
      The BLE central role entry point -- scanning, connections, GATT client. Never null: on ports without BLE a no-op instance is returned whose operations fail fast with BluetoothError.NOT_SUPPORTED; branch via isLeSupported().

    • getClassic

      public BluetoothClassic getClassic()
      The classic Bluetooth role entry point -- discovery, bonding and RFCOMM streams. Never null: on ports without classic Bluetooth (iOS among them) a no-op instance is returned whose operations fail fast with BluetoothError.NOT_SUPPORTED; branch via isClassicSupported().

    • hasPermission

      public boolean hasPermission(BluetoothPermission permission)
      true when the given runtime permission is currently granted. See BluetoothPermission for the per-platform mapping. Defaults to false.

    • requestPermissions

      public AsyncResource<Boolean> requestPermissions(BluetoothPermission... permissions)
      Requests the given runtime permissions, prompting the user where needed. Resolves true when every requested permission is granted. Resolves false (rather than failing) when denied or when the platform has no Bluetooth support at all.