How to Validate Email Address using Java Pattern

Validate an email address is easy if you have good valid pattern expression.   

package com.jsupport;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 *
 * @author JSupport
 */
public class ValidateEmailAddress {

    public boolean isValidEmailAddress(String emailAddress) {
        
        String expression = "^[\\w\\-]([\\.\\w])+[\\w]+@([\\w\\-]+\\.)+[A-Z]{2,4}$";
        CharSequence inputStr = emailAddress;
        Pattern pattern = Pattern.compile(expression, Pattern.CASE_INSENSITIVE);
        Matcher matcher = pattern.matcher(inputStr);
        return matcher.matches();
        
    }

    public static void main(String[] args) {
        
        ValidateEmailAddress vea = new ValidateEmailAddress();

        System.out.println(vea.isValidEmailAddress("info@jsupport.info"));      // Valide emaill address
        System.out.println(vea.isValidEmailAddress("info@jsup@port.info"));     // Invalide emaill address
        System.out.println(vea.isValidEmailAddress("info@jsupport.in_fo"));     // Invalide emaill address
        System.out.println(vea.isValidEmailAddress("in@fo@jsupport.info"));     // Invalide emaill address
        System.out.println(vea.isValidEmailAddress("info@jsupport.com.lk"));    // Valide emaill address
    }
}

Here you will find how to validate email address using Java Mail API

Read more...

How to Resize Image according to the screen size using Java

package jsupport.com;

import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;

/**
 *
 * @author JSupport
 */
public class ResizeImage {

    private  URL url = null;

    public  BufferedImage resize() {
        try {
                url = getClass().getResource("/images/image.jpeg");
                BufferedImage originalImage = ImageIO.read(url);
                Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();

                int screenWidth = (int) dim.getWidth();
                int screenHeight = (int) dim.getHeight();

                int w = originalImage.getWidth();
                int h = originalImage.getHeight();
                BufferedImage dimg = dimg = new BufferedImage(screenWidth, screenHeight, originalImage.getType());
                Graphics2D g = dimg.createGraphics();
                g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
                g.drawImage(originalImage, 0, 0, screenWidth, screenHeight, 0, 0, w, h, null);
                g.dispose();

                return dimg;
        }catch (IOException ex) {
            ex.printStackTrace();
            return null;
        }
    }
}

Read more...

How To Get Installed Printer name using Java

Get Installed printers in Java

• You can get installed printers by using both javax.print.PrintService and javax.print.PrintServiceLookup 
• PrintServiceLookup.lookupDefaultPrintService().getName(); will gives default printer name;

package jsupport.com;

import javax.print.PrintService;
import javax.print.PrintServiceLookup;

/**
 *
 * @author Jsupport
 */

public class ShowPrinters {

    String defaultPrinter;
    public void SearchPrinter() {
        PrintService[] ser = PrintServiceLookup.lookupPrintServices(null, null);

        System.out.println("**************** All Printers ******************");
        for (int i = 0; i < ser.length; ++i) {
            String p_name = ser[i].getName();
            System.out.println(p_name);
        }
        System.out.println("***********************************************\n");
        defaultPrinter  =   PrintServiceLookup.lookupDefaultPrintService().getName();
        System.out.println("Default Printer  : "+defaultPrinter );
    }

    public static void main(String[] args) {
        new ShowPrinters().SearchPrinter();
    }
}

Read more...

How to Read Property file using Java - Get Database connection parameters from property file

• Here is the java class to read property file which will help to create database connection. 

package jsupport.com.db;

import java.io.FileInputStream;
import java.io.IOException;
import java.util.Properties;

/**
 *
 * @author JSupport http://javasrilankansupport.blogspot.com/
 */
public class ReadPropertyFile {

    public static String db_driver;
    public static String db_url;
    public static String db_username;
    public static String db_password;

    static {
        try {
            Properties prop = new Properties();
            prop.load(new FileInputStream("Config.properties"));

            String driver = prop.getProperty("db_driver");
            String ip = prop.getProperty("db_ip");
            String dbName = prop.getProperty("db_name");

            db_username = prop.getProperty("db_username");
            db_password = prop.getProperty("db_password");

            if (driver.equals("SQL2000")) {
                db_driver = "com.microsoft.jdbc.sqlserver.SQLServerDriver";
                db_url = "jdbc:microsoft:sqlserver://" + ip + ":1433;DatabaseName=" + dbName;
            } else if (driver.equals("SQL2005")) {
                db_driver = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
                db_url = "jdbc:sqlserver://" + ip + ":1433;databaseName=" + dbName;
            } else if (driver.equals("MySQL")) {
                db_driver = "com.mysql.jdbc.Driver";
                db_url = "jdbc:mysql://" + ip + ":3306/" + dbName;
            }

            System.out.println("Database Driver :"+db_driver+ " Database URL :"+db_url);

        } catch (IOException ex) {
            System.out.println("Can not read property file...");
        }
    }
}

• Create Config.properties under your source code package and add following properties 

Config.properties

# JSupport http://javasrilankansupport.blogspot.com/

#databace properties

#db_driver=SQL2000

#db_driver=SQL2005

db_driver=MySQL

db_ip=localhost

db_name=mysql

db_username=root

db_password=123

Read more...

Connect To Access Database Using Java

package jsupport.com.db;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author Jsupport
 */
public class AccessDatabaseConnection {

    public static Connection connect() {

        Connection con;
        try {

            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
            String database = "jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ=Data.mdb;";
            con = DriverManager.getConnection(database, "Admin", "64");

        } catch (Exception ex) {
            return null;
        }
        return con;
    }

    public void getData(){

        try {

            Statement stmt = connect().createStatement();
            ResultSet rset = stmt.executeQuery("SELECT * FROM tblData");

            if (rset.next()) {

                String name     = rset.getString("user_name");
                String email    = rset.getString("user_email");

                System.out.println("Name  : " +name +"  Email : "+email);
            }


        } catch (SQLException ex) {
            
        }
    }

    public static void main(String[] args) {
        new AccessDatabaseConnection().getData();
    }
}

Access Database table


     Data.mdb

Read more...

How To Create XML File in JAVA - (DOM)

In Java, we can create XML by using DOM class.


Example :


This is the XML format you  create latter

<?xml version="1.0" encoding="UTF-8" ?>
 <order>
 <orderDetails>
  <waiterName>Siridasa</waiterName>
  <kitchName>Chines Kitchen</kitchName>
  <tableName>20</tableName>
  </orderDetails>
<item>
  <itemid>ARR01</itemid>
  <itemName>DCL White Arak</itemName>
  <itemQty>1</itemQty>
  </item>
 <item>
  <itemid>ARR02</itemid>
  <itemName>Lemon Gin</itemName>
  <itemQty>2</itemQty>
  </item>
 <item>
  <itemid>ARR03</itemid>
  <itemName>Ritz</itemName>
  <itemQty>10</itemQty>
  </item>
  </order>

package jsupport.xml;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

import javax.xml.parsers.*;
import javax.xml.transform.*;
import javax.xml.transform.dom.*;
import javax.xml.transform.stream.*;
import org.w3c.dom.*;

/**
 *
 * @author JSupport http://javasrilankansupport.blogspot.com
 */
public class CreateXML {

    DocumentBuilderFactory documentBuilderFactory;
    DocumentBuilder documentBuilder;
    Document document;

    public void createXML(Map order_details, ArrayList item_details) {

        Set set;
        Iterator iterator;

        try {
//              Creating an empty XML Document

            documentBuilderFactory = DocumentBuilderFactory.newInstance();
            documentBuilder = documentBuilderFactory.newDocumentBuilder();
            document = documentBuilder.newDocument();

//               Creating XML tree
//               create the root element and add it to the document

            Element orderElement = document.createElement("order");
            document.appendChild(orderElement);

            Element orderDetailElement = document.createElement("orderDetails");
            orderElement.appendChild(orderDetailElement);

            set = order_details.keySet();
            iterator = set.iterator();

//                create child element acording to the key set,add an attribute, and add to root (orderDetails)

            while (iterator.hasNext()) {

                String key = (String) iterator.next();
                Element detailElement = document.createElement(key);
                detailElement.appendChild(document.createTextNode((String) order_details.get(key)));
                orderDetailElement.appendChild(detailElement);

            }

            for (int i = 0; i < item_details.size(); i++) {

//                  create item element and add item details as child

                Element itemElement = document.createElement("item");
                orderElement.appendChild(itemElement);

                Element itemId;
                String itemdetails[] = (String[]) item_details.get(i);


                itemId = document.createElement("itemid");
                itemId.appendChild(document.createTextNode(itemdetails[0]));

                itemElement.appendChild(itemId);
                itemId = document.createElement("itemName");
                itemId.appendChild(document.createTextNode(itemdetails[1]));

                itemElement.appendChild(itemId);
                itemId = document.createElement("itemQty");
                itemId.appendChild(document.createTextNode(itemdetails[2]));
                itemElement.appendChild(itemId);

            }

//              create XML file


            File xmlFile = new File("C:\\Test.xml");
            xmlFile.createNewFile();
            FileOutputStream isod = new FileOutputStream(xmlFile);
            TransformerFactory transformerFactory = TransformerFactory.newInstance();
            Transformer transformer = transformerFactory.newTransformer();

            DOMSource source = new DOMSource(document);
            StreamResult result = new StreamResult(isod);
            transformer.transform(source, result);

            isod.flush();
            isod.close();

        } catch (IOException ex) {
            ex.printStackTrace();
        } catch (TransformerException ex) {
            ex.printStackTrace();
        } catch (ParserConfigurationException ex) {
            ex.printStackTrace();
        }

    }

    public static void main(String[] args) {


        CreateXML cXML = new CreateXML();
        Map order_details = new HashMap();
        ArrayList item_details = new ArrayList();
        String itemDetails[] = new String[3];
        String itemDetails2[] = new String[3];
        String itemDetails3[] = new String[3];

//     add order details
        order_details.put("kitchName", "Chines Kitchen");
        order_details.put("waiterName", "Siridasa");
        order_details.put("tableName", "20");

//     add item details
        itemDetails[0] = "ARR01";
        itemDetails[1] = "DCL White Arak";
        itemDetails[2] = "1";
        item_details.add(itemDetails);

        itemDetails2[0] = "ARR02";
        itemDetails2[1] = "Lemon Gin";
        itemDetails2[2] = "2";
        item_details.add(itemDetails2);

        itemDetails3[0] = "ARR03";
        itemDetails3[1] = "Ritz";
        itemDetails3[2] = "10";
        item_details.add(itemDetails3);

        cXML.createXML(order_details, item_details);

    }
}

Read more...