Delphi在Android下使用Java库的方法

set path="C:\Program Files (x86)\Java\jdk1.8.0_144\bin";%PATH%
set path=%BDS%\bin\converters\java2op";%PATH%
java2op -jar classes.jar Android.JNI.UsbSerial.pas

function GetUsbManager: JUsbManager;

var UsbManagerService: JObject;

begin

 UsbManagerService := SharedActivity.getSystemService(TJContext.JavaClass.USB_SERVICE);

 Result := TJUsbManager.Wrap((UsbManagerService as ILocalObject).GetObjectID);

end;

function GetUsbDevices: TArray<JUsbDevice>;
var
 UsbManager: JUsbManager;
 UsbDeviceList: JHashMap;
 UsbDeviceListIterator: JIterator;
 I: Integer;
begin
 UsbManager := GetUsbManager;
 if UsbManager <> nil then
 begin
  UsbDeviceList := UsbManager.getDeviceList;
  SetLength(Result, UsbDeviceList.size);
 
  UsbDeviceListIterator := UsbDeviceList.values.iterator;
  for I := 0 to Length(Result) - 1 do
   Result[I] := TJUsbDevice.Wrap((UsbDeviceListIterator.next as ILocalObject).GetObjectID);
 end;
end;

function GetUsbConnection(Device: JUsbDevice): JUsbDeviceConnection;
var UsbManager: JUsbManager;
begin
 UsbManager := GetUsbManager;
 if UsbManager <> nil then
  Result := UsbManager.openDevice(Device);
end; 
　
//创建USB串口
 SerialDevice := TJUsbSerialDevice.JavaClass.createUsbSerialDevice(UsbDevice, UsbConnection);
 if SerialDevice = nil then
 begin
  raise Exceptioin.Create('Cannot create serial device');
  Exit;
 end;
//打开USB串口
 if not SerialDevice.syncOpen then
 begin
  raise Exception.Create('Cannot open serial device');
  SerialDevice := nil;
  UsbConnection.close;
  UsbConnection := nil;
  Exit;
 end; 
//串口设置
SerialDevice.setBaudRate(9600);
SerialDevice.setDataBits(TJUsbSerialInterface_DATA_BITS_8);
SerialDevice.setStopBits(TJUsbSerialInterface_STOP_BITS_1);
SerialDevice.setParity(TJUsbSerialInterface_PARITY_NONE);
SerialDevice.setFlowControl(TJUsbSerialInterface_FLOW_CONTROL_OFF); 
//读串口：
if SerialDevice.syncRead(ReadBuffer, 50) >= 1 then
 Data := Data + TEncoding.UTF8.GetString(ToByteArray(ReadBuffer)); 
　　
//写串口
  SerialDevice.syncWrite(WriteBuffer, 1000);