Barcode scanner

Barcode scanner


Everybody knows QR code format, and we can generate it at http://www.the-qrcode-generator.com:

1.
 http://kdabrowski.blogspot.com

2.
http://jeeprojectsnippets.com

3.
http://jeeproject.com

4.
Bus ticket:

We focus on barcodes now...

An example of EAN-13 format of barcode:

Another example of CODE39 format of barcode:

CODE128/EAN-128 format of barcode:

EAN-8 format of barcode:

Interleaved 2 of 5:

How can we use it?
Assume that we have barcode scanner, printer and display and we want to build single point of sale.

Let's begin...

-----------------------------------------

package com.jeeprojectsnippets.pos.entity;

import java.io.Serializable;

import com.jeeprojectsnippets.pos.entity.base.EntTable;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.Table;

/**
 * Entity class for table: "pos_Product"
 */

@Entity
@Table(name = "pos_Product")
@NamedQueries({
    @NamedQuery(name = "EntProduct.findById", query = "SELECT p FROM EntProduct p WHERE id = :id "),
    @NamedQuery(name = "EntProduct.findByBarcode", query = "SELECT p FROM EntProduct p WHERE barcode = :barcode ")
})
public class EntProduct extends EntTable implements Serializable {

    private static final long serialVersionUID = 1L;

    @Column(name = "barcode")
    private Long barcode;
   
    @Column(name = "price")
    private double price;

    /**
     * @return the barcode
     */
    public Long getBarcode() {
        return barcode;
    }

    /**
     * @param barcode the barcode to set
     */
    public void setBarcode(Long barcode) {
        this.barcode = barcode;
    }

    /**
     * @return the price
     */
    public double getPrice() {
        return price;
    }

    /**
     * @param price the price to set
     */
    public void setPrice(double price) {
        this.price = price;
    }
}

-------------------------------------------

package com.jeeprojectsnippets.pos.entity.base;

import java.io.Serializable;

import javax.persistence.Column;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

/**
 * Auxliary class for Entity classes
 */
public class EntTable implements Serializable {

    private static final long serialVersionUID = -2L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    @Column(name = "name")
    private String name;

    /**
     * @return the id
     */
    public Integer getId() {
        return id;
    }

    /**
     * @param id the id to set
     */
    public void setId(Integer id) {
        this.id = id;
    }

    /**
     * @return the name
     */
    public String getName() {
        return name;
    }

    /**
     * @param name the name to set
     */
    public void setName(String name) {
        this.name = name;
    }
}
-------------------------------------------
USE `myDB`;

CREATE TABLE pos_Product
(
    `id` INTEGER NOT NULL,
    `name` VARCHAR(45) NULL DEFAULT NULL,
    `barcode` LONG NULL,
    `price` DOUBLE NULL,
    PRIMARY KEY (`id`)
) ;

COMMIT;

INSERT INTO `sio2`.`pos_product` (`id`, `name`, `barcode`, `price`) VALUES (33, 'cheese', '1234567890123', 13.3);
INSERT INTO `sio2`.`pos_product` (`id`, `name`, `barcode`, `price`) VALUES (34, 'butter', '1234567890124', 14.44);
INSERT INTO `sio2`.`pos_product` (`id`, `name`, `barcode`, `price`) VALUES (35, 'milk', '1234567890125', 15.0);
INSERT INTO `sio2`.`pos_product` (`id`, `name`, `barcode`, `price`) VALUES (36, 'bread', '1234567890126', 16);

COMMIT;

-------------------------------------------
package com.jeeprojectsnippets.pos.entity.manager;

import javax.ejb.Local;

import com.jeeprojectsnippets.pos.entity.EntProduct;

@Local   
/**
 * ProductManager interface to DAO operations of EntProduct object
 */                                                                               
public interface ProductManager     {
    public EntProduct saveAndRefresh(EntProduct entProduct);
    public EntProduct findById(int id);
    public EntProduct findByBarcode(Long barcode);
    public T find(Class entityClass, int id);
}
-------------------------------------------
package com.jeeprojectsnippets.pos.entity.manager.impl;

import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;

import com.jeeprojectsnippets.pos.entity.EntProduct;
import com.jeeprojectsnippets.pos.entity.manager.ProductManager;
import com.jeeprojectsnippets.pos.io.PosConstants;

@Stateless(name = "ProductManagerImpl")
/**
 * Class, which implements ProductManager interface
 */                                                                           
public class ProductManagerImpl    implements ProductManager, PosConstants {

    @PersistenceContext(unitName = "Scanning")
    private EntityManager em;

    @Override
    public EntProduct saveAndRefresh(EntProduct entProduct) {
        em.persist(entProduct);
        em.refresh(entProduct);
        return entProduct;
    }
   
    @Override
    public EntProduct findById(int id) {
        EntProduct entProduct = em.find(EntProduct.class, id);
        return entProduct;
    }

    @Override
    public T find(Class entityClass, int id) {
 
        return em.find(entityClass, id);
    }

    @Override
    public EntProduct findByBarcode(Long barcode)
            throws javax.persistence.NoResultException,
            javax.persistence.NonUniqueResultException{

        Query que = em.createNamedQuery("EntProduct.findByBarcode");
        que.setParameter("barcode", barcode);
       
        EntProduct resu = (EntProduct) que.getSingleResult();
        return resu;
    }
}
-------------------------------------------
package com.jeeprojectsnippets.pos;

import java.util.ArrayList;
import java.util.List;

import com.jeeprojectsnippets.pos.io.PosConstants;
import com.jeeprojectsnippets.pos.entity.EntProduct;
import com.jeeprojectsnippets.pos.entity.manager.ProductManager;

import javax.ejb.EJB;
   
public class POSApp implements PosConstants {
   
    private static Scanner scanner = null;
    private static Display display = null;
    private static Printer printer = null;
    private static UserButtonListener userButtonListener = null;
   
    private static EntProduct entProduct = null;
    private static List entProductList = null;
   
    @EJB
    private static ProductManager productManager = null;
   

   
    public static void init(){
        setScanner(new Scanner());
        setDisplay(new Display());
        setPrinter(new Printer());
        setUserButtonListener(new UserButtonListener());
    }
   
    private static void run() throws Exception{
        try{
            Long barcode = Long.parseLong(getScanner().scan());
            setEntProduct(getProductManager().findByBarcode(barcode));
            getEntProductList().add(getEntProduct());
            getDisplay().display(getEntProduct().getName() + " " + getEntProduct().getPrice() + "\n");
        } catch (java.lang.NumberFormatException e){
            getDisplay().display(ERROR_MSG_INVALID_BARCODE_NAME);
        } catch (javax.persistence.NoResultException e) {
            getDisplay().display(ERROR_MSG_PRODUCT_NOT_FOUND_NAME);
        } catch (javax.persistence.NonUniqueResultException e) {
            getDisplay().display(ERROR_MSG_MORE_THAN_ONE_PRODUCT_FOUND_NAME);
        }catch(Exception ex){
            // TODO logger.debug(ex.getMessage());
            System.out.println(ex.getMessage());
            throw new Exception(ex.getMessage());
        }finally{
            // TODO clean if needed
        }
       
    }
   
    protected static String act() throws Exception{
        double sum = 0;
            while(!EVENT_EXIT.equals(getUserButtonListener().watch())){
                setEntProductList(new ArrayList(1));
                run();
                for (EntProduct entProduc : getEntProductList()){
                    getPrinter().print(entProduc.getName() + " " + entProduc.getPrice() + "\n");
                    sum += entProduc.getPrice();
                }
            }
            getPrinter().print("TOTAL: " + sum + "\n");
            getDisplay().display("TOTAL: " + sum + "\n");
            return Double.toString(sum);
    }
   

    public static void main(String[] args) throws Exception {
        init();
        while(true){
            act();
        }
    }

    /**
     * @return the scanner
     */
    public static Scanner getScanner() {
        return scanner;
    }
   
    (...)

}
-------------------------------------------

package com.jeeprojectsnippets.pos;

import com.jeeprojectsnippets.pos.io.BarCodeReader;
import com.jeeprojectsnippets.pos.io.impl.BarCodeReaderImpl;

class Scanner implements BarCodeReader {
    private BarCodeReader adaptee = new BarCodeReaderImpl();

    public String read() {
        return adaptee.read();
    }

    public String scan() {
        return read();
    }
}


-------------------------------------------

package com.jeeprojectsnippets.pos;

import com.jeeprojectsnippets.pos.io.DisplayWriter;
import com.jeeprojectsnippets.pos.io.impl.DisplayWriterImpl;

class Display implements DisplayWriter
{
    private DisplayWriter adaptee = new DisplayWriterImpl();
    public boolean write(String msg) {
        return adaptee.write(msg);
    }

    public boolean display(String msg) {
        return write(msg);
    }
}


-------------------------------------------

package com.jeeprojectsnippets.pos;

import com.jeeprojectsnippets.pos.io.PrinterWriter;
import com.jeeprojectsnippets.pos.io.impl.PrinterWriterImpl;

class Printer implements PrinterWriter {
    private PrinterWriter adaptee = new PrinterWriterImpl();

    public boolean write(String msg) {
        return adaptee.write(msg);
    }

    public boolean print(String msg) {
        return write(msg);
    }
}

-------------------------------------------

package com.jeeprojectsnippets.pos;

import com.jeeprojectsnippets.pos.io.UserReactionReader;
import com.jeeprojectsnippets.pos.io.impl.UserReactionReaderImpl;

class UserButtonListener implements UserReactionReader {
    private UserReactionReader adaptee = new UserReactionReaderImpl();

    public String listen() {
        return adaptee.listen();
    }
   
    public String watch() {
        return listen();
    }
}

-------------------------------------------

So we have a little shop now :-)