Java exception was raised during method invocation ionic3 barcodescanner corodova plugin

Hi,

I’m developing ionic3 angular corodova app, where I need to use a barcode scanner. When I use scanner first time its working fine, when I try to scan next time, its throwing Java error -
Java exception was raised during method invocation

Following is my code

app.module.ts

import { BarcodeScanner } from '@ionic-native/barcode-scanner';

 providers: [
    StatusBar,
    SplashScreen,
    AndroidPermissions,
    BarcodeScanner,
    {provide: ErrorHandler, useClass: IonicErrorHandler}
 ]

shoppingcart.ts

import { BarcodeScanner } from '@ionic-native/barcode-scanner';
import { AndroidPermissions } from '@ionic-native/android-permissions';

constructor(private barcodeScanner: BarcodeScanner, public androidPermissions: AndroidPermissions)

 public checkPermission(){
    this.androidPermissions.checkPermission(this.androidPermissions.PERMISSION.CAMERA)
        .then(status => {
          if (status.hasPermission) {
            this.scanProduct();
          } else {
            this.androidPermissions.requestPermission(this.androidPermissions.PERMISSION.CAMERA)
            .then(status =>{
              if(status.hasPermission) this.scanProduct();
            });
          }
        })       
}  

public scanProduct(){
      this.barcodeScanner.scan().then(barcodeData => {
        console.log('Barcode data', barcodeData);
        if(!barcodeData.cancelled){
          var partNo = barcodeData.text;
          if(partNo.length > 7){
            partNo = partNo.split('')[1].substr(2, 9);
          } 
          this.productDetails(partNo)
        }else{
          alert("Scan Cancelled");
        }
       }).catch(err => {
           console.log('Error', err);
       }),
       {       
         prompt : "Scan QR code on Applied Biosystems reagent box"//,
       };
}

public productDetails(id: any){
  this.navCtrl.push(ProductDetailsPage, {id: id});
}

Finally I will show the identifeid product in a iframe.

Please help me, someone, what mistake I am doing in my code.