Android Question Printing on a usb thermal printer using external lib and javaobject

[fabton1963]

Hello,
I'm trying to translate the following java code from an external jar using javaobject:

public class MainActivity extends Activity {
 …
 private Printer mPrinter;
 …
 public void onCreate(Bundle savedInstanceState) {
  …
  mPrinter = new Printer(this, mHandler, null);   
  mPrinter.findUsbPrinters();
   
 } 
 private final Handler mHandler = new Handler(new Handler.Callback() {
        public boolean handleMessage(Message msg) {   
            switch (msg.what) {   
            case Printer.MESSAGE_USB_DEVICE_SET:     
                Set<UsbDevice> usbDeviceSet = (Set<UsbDevice>) msg.obj;     
                for (UsbDevice device : usbDeviceSet) {     
                    if (device.getProductId() == 0x6D) {       
                        mPrinter.connect(device);       
                        break;     
                    }     
                }     
            return true;

            case Printer.MESSAGE_STATE_CHANGE:     
                switch (msg.arg1) {     
                    case Printer.STATE_CONNECTING:      // TODO: Processing when connection to printer is being tried     
                    break;
                    case Printer.STATE_CONNECTED:      // TODO: Processing when printer connection is completed 
                    mPrinter.printText(“This is a test\n”,0,1,0,true)
                    break;
                    case Printer.STATE_NONE:      // TODO: Processing when printer is not connected     
                    break;     
                }     
            break;
            
            case Printer.MESSAGE_PRINT_COMPLETE:     
                mPrinter.disconnect();     
            break;

            case Printer.MESSAGE_DEVICE_NAME:     
                String connectedDeviceName = msg.getData().getString( Printer.KEY_STRING_DEVICE_NAME);     
            break;

            case Printer.MESSAGE_TOAST:     
                Toast.makeText(getApplicationContext(),msg.getData().getString(Printer.KEY_STRING_TOAST), Toast.LENGTH_SHORT).show();     
            break;   
            }   
            return true;   
        } 
    };
}

I try whith the following code:

#AdditionalJar: printer

Sub Activity_Create(FirstTime As Boolean)
    'Do not forget to load the layout file created with the visual designer. For example:
    oprinter.InitializeStatic("com.printer.posbank.Printer")
    
    Dim ctxt As JavaObject
    ctxt.InitializeContext

    mprinter.InitializeNewInstance("com.printer.posbank.Printer", Array(ctxt))
    mprinter.RunMethod("findUsbPrinters",Null)
    
    Activity.LoadLayout("1")
    
End Sub

mprinter.RunMethod("findUsbPrinters",Null) raise "java.lang.RuntimeException: Constructor not found." error.

Need help please.

 

[stevel05]

Without seeing the documentation it's difficult to speculate, but the first thing to check is that the printer constructor appears to need 3 parameters:

mPrinter = new Printer(this, mHandler, null);

You are passing it one

mprinter.InitializeNewInstance("com.printer.posbank.Printer", Array(ctxt))

If there is not a one parameter constructor, this is why the constructor cannot be found.