扫描已匹配的蓝牙设备

1.在AndroidManifest.xml中配置

2.

			//1.获得BluetoothAdapter对象
			BluetoothAdapter adapter=BluetoothAdapter.getDefaultAdapter();
			//2.判断当前设备中是否拥有蓝牙设备
			if(adapter != null){
				System.out.println("本机拥有蓝牙设备");
			}
			
			//3.判断当前设备中的蓝牙设备是否已经打开
			if(adapter.isEnabled()){
				Intent intent=new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
				startActivity(intent);
			}
			//4.得到所有已经配对的蓝牙设备对象
			Set devices=adapter.getBondedDevices();
			if(devices.size() >0){
				for(Iterator iterator= devices.iterator(); iterator.hasNext();){
					BluetoothDevice bluetoothDevice=(BluetoothDevice) iterator.next();
					System.out.println(bluetoothDevice.getAddress());
				}
			}else{
				System.out.println("没有蓝牙设备！");
			}
			
		}