Get user input using java swing and write to text file

import java.io.*;
import javax.swing.JOptionPane;
import java.util.Scanner;

public class ClientList
{
public static void main (String args[]) throws IOException
	{
	 // Main class ClientList creates Clients.txt file that is to be opened up and appended whenever clients are to be added
		FileWriter outFile = new FileWriter("Clients.txt");
		BufferedWriter outStream = new BufferedWriter(outFile);
		String outString = "Client Listing";
		outStream.write(outString);
		outStream.newLine();
		outStream.close();
		System.out.println("Clients.txt is created\n");

	 // "Primitive" menu asks user what he/she wants to do and accepts commands via keyboard scanner
		Scanner menu = new Scanner(System.in);
		System.out.println("Welcome to ClientList");
		System.out.println();
		System.out.println("To add clients to the file, enter 1");
		System.out.println("To open file and view its contents, enter 2");
	 //	System.out.println("To search for a client in the file, enter 3");
		int command = menu.nextInt();

		switch (command)
		{
		case 1: Clients client = new Clients();
				client.enterData();
	    		break;
	    case 2: Clients client2 = new Clients();
	    		client2.getClients();
	    		break;
	 // case 3: Clients client = new Clients();
	 //			client.searchClients();
	 //   		break;
	    default: System.out.println("Doesn't exist!");
	    		 System.out.print("Enter a valid number ===> ");
	    	     int l = menu.nextInt();
	    	     break;
		}
	}
}

class Clients
	{
	 // Initializing variables for client data
		String firstName;
 		String lastName;
 		String age;
 		String height;
 		String weight;
 		String startDate;
 		String phNum;

		public void enterData() throws IOException
 		{
 	 // Initializing boolean variable isValid to check the number of clients user inputs
 	 // and make sure it really IS a number
 		boolean isValid = false;
 		String number;

 	 // Ask user how many clients he/she wishes to enter data for
 	 	do
 	 	{
		number = JOptionPane.showInputDialog("Enter the number of clients you wish to save:");
	 // Loop to check what the user entered against the allowed charcters (only numbers between 0 and 9 allowed)
		if (number.matches("[0-9]*"))
 	 	{
        isValid = true;
        }
        else
        {
        isValid = false;
        }
 	 	}
 	 	while (isValid != true); // Keeps prompting user for a number until a valid number between 0 and 9 is entered
 	 // Finally, parse String number and change to an integer for use in data input loop
		int numOfClients = Integer.parseInt(number);

	 // Data input prompts are put into a loop that repeats until data for all clients is entered
		for (int k = 0; k 

How to iterate throught a Map

//Declare a map object
Map mapObj = new HashMap();
//iterate through the map objects elements one by one 
for (Map.Entry entry : mapObj.entrySet()) {

       System.out.println(entry.getKey() + ": " + entry.getValue());

    }

how to convert Byte[] array to String in Java

public class ByteToString
{    
	public static void main(String[] args) {
 
		    String example = "This is an example";
		    byte[] bytes = example.getBytes();
 
		    System.out.println("Text : " + example);
		    System.out.println("Text in Byte Format] : " + bytes);
		    System.out.println("Text in Byte Format] : " + bytes.toString());
 
		    String s = new String(bytes);
		    System.out.println("Text converted : " + s);
 
 
	}
}

Java program to insert image into database

This is a simple java program used to inject an image into the mysql database:

import java.sql.*;
import java.io.*;

public class insertImg{
    public static void main(String[] args) {

        System.out.println("Insert Image Example!");
        String driverName = "com.mysql.jdbc.Driver";
        String url = "jdbc:mysql://localhost:3306/";
        String dbName = "hibernatetutorial";
        String userName = "root";
        String password = "root";
        Connection con = null;

        try {
            Class.forName(driverName);
            con = DriverManager.getConnection(url+dbName,userName,password);
            Statement st = con.createStatement();

            File imgfile = new File("images.jpg");
            FileInputStream fin = new FileInputStream(imgfile);

            PreparedStatement pre = con.prepareStatement("insert into Image values(?,?,?)");
            pre.setInt(1,5);
            pre.setString(2,"Durga");
            pre.setBinaryStream(3,fin,(int)imgfile.length());
            pre.executeUpdate();

            System.out.println("Inserting Successfully!");

            pre.close();
            con.close();  

        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }
} 

How to extract a war file

Download 7-zip and extract it!!simple..

Retrieve and Store BLOB from/to MySQL in Java awt

This post shows you how to insert an image into MySQL database through Java Step 1 : Open MySQL client Step 2 : Execute the following query

CREATE TABLE IF NOT EXISTS `image` (

IMG blob,

IMG_ID int NOT NULL AUTO_INCREMENT,

PRIMARY KEY (`IMG_ID`)

)

Source code -----------

import java.awt.event.ActionEvent;

import java.sql.*; 
import java.awt.Graphics;

import java.awt.event.ActionListener;

import java.awt.image.BufferedImage;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStream;

import javax.imageio.ImageIO;

import javax.swing.JButton;

import javax.swing.JFileChooser;

import javax.swing.JFrame;

import javax.swing.JOptionPane;

import javax.swing.JPanel;

/**

*

* @author mustaq

*/

public class ImagePanel extends JPanel implements ActionListener {

JButton browse;

Connection con = null;

public ImagePanel() {

con = this.getConnection();

browse = new JButton("Browse");

browse.addActionListener(this);

this.add(browse);

}

public Connection getConnection() {

try {

// Creating connection to DB

Class.forName("com.mysql.jdbc.Driver");

String url = "jdbc:mysql://localhost:3306/image";

Connection c = DriverManager.getConnection(url,"root","");

return c;

}

catch(Exception ex) {

System.out.println(ex.getMessage());

return null;

}

}

public void imageWrite(File file) {

try {

FileInputStream io = new FileInputStream(file);

String query = "insert into image(IMG) values(?)";

java.sql.PreparedStatement stmt = con.prepareStatement(query);

stmt.setBinaryStream(1, (InputStream)io,(int)file.length());

stmt.executeUpdate();

}

catch(Exception ex) {

System.out.println(ex.getMessage());

}

}

public BufferedImage getImageById(int id) {

String query = "select IMG from image where IMG_ID = ?";

BufferedImage buffimg = null;

try {

PreparedStatement stmt = con.prepareStatement(query);

stmt.setInt(1,id);

ResultSet result = stmt.executeQuery();

result.next();

InputStream img = result.getBinaryStream(1); // reading image as InputStream

buffimg= ImageIO.read(img); // decoding the inputstream as BufferedImage

}

catch(Exception ex) {

System.out.println(ex.getMessage());

}

return buffimg;

}

@Override

public void paint(Graphics g) {

BufferedImage img = this.getImageById(5) ; // pass valid IMG_ID

if(img != null)

g.drawImage(img, 70, 20, this); 

}

public static void main(String[] args) {

JFrame frame = new JFrame("ImagePanel Demo");

ImagePanel imgPanel = new ImagePanel();

frame.setVisible(true);

frame.setSize(600, 400);

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

frame.getContentPane().add(imgPanel);

}

public void actionPerformed(ActionEvent e) {

JFileChooser chooser = new JFileChooser();

int returnVal = chooser.showOpenDialog(null);

File file = null;

if(returnVal == JFileChooser.APPROVE_OPTION) {

file = chooser.getSelectedFile(); // path to image

this.imageWrite(file); // inserting image into database

JOptionPane.showMessageDialog(this, "Image inserted.", "ImageDemo", JOptionPane.PLAIN_MESSAGE);

this.repaint();

}

}

}

Converting byte array to base64 string in java

public class ImageProcessing {
 
    /**
     * @param args
     */
    public static void main(String[] args) {
        File file = new File("/Users/Lakshman/Pictures/image.jpeg");
 
        try {
            // Reading a Image file from file system
            FileInputStream imageInFile = new FileInputStream(file);
            byte imageData[] = new byte[(int) file.length()];
            imageInFile.read(imageData);
 
            // Converting Image byte array into Base64 String
            String imageDataString = encodeImage(imageData);
 
            // Converting a Base64 String into Image byte array
            byte[] imageByteArray = decodeImage(imageDataString);
 
            // Write a image byte array into file system
            FileOutputStream imageOutFile = new FileOutputStream(
                    "/Users/Lakshman/Pictures/image.jpeg");
            imageOutFile.write(imageByteArray);
 
            imageInFile.close();
            imageOutFile.close();
 
            System.out.println("Image Successfully Manipulated!");
        } catch (FileNotFoundException e) {
            System.out.println("Image not found" + e);
        } catch (IOException ioe) {
            System.out.println("Exception while reading the Image " + ioe);
        }
 
    }
 
    /**
     * Encodes the byte array into base64 string
     *
     * @param imageByteArray - byte array
     * @return String a {@link java.lang.String}
     */
    public static String encodeImage(byte[] imageByteArray) {
        return Base64.encodeBase64URLSafeString(imageByteArray);
    }
 
    /**
     * Decodes the base64 string into byte array
     *
     * @param imageDataString - a {@link java.lang.String}
     * @return byte array
     */
    public static byte[] decodeImage(String imageDataString) {
        return Base64.decodeBase64(imageDataString);
    }
}

Upload an image into the database in java

<%@page contentType="text/html"%>

<%@page pageEncoding="UTF-8"%>

<%@ page language="java" %>

<%@ page import="java.awt.image.*"%>

<%@ page import="java.io.*"%>

<%@ page import="java.sql.*"%>

<%@ page import="java.io.File"%>

<%@ page import="javax.imageio.ImageIO"%>

<%@ page import="java.awt.image.BufferedImage,java.util.*"%>

<%@ page import="java.awt.*"%>

<%@ page import="java.util.*,com.oreilly.servlet.MultipartRequest"%>

<%

/* The Following Code is Used To Insert An Image Into Database */

String filename="";

try

{

//Download com.oreilly package

MultipartRequest multi= new MultipartRequest(request,".",5*1024*1024);

Enumeration files=multi.getFileNames();

File f=null;

while(files.hasMoreElements())

{

String name=(String)files.nextElement();

filename=multi.getFilesystemName(name);

String type=multi.getContentType(name);

f=multi.getFile(name);

System.out.println("The File is "+f);

}

Connection con=null;

String userName="root";

String password = "veradis";

Class.forName("com.mysql.jdbc.Driver");

con = DriverManager.getConnection("jdbc:mysql://localhost:3306/sample",userName,password);

Statement stmt = con.createStatement();

InputStream is = new FileInputStream(f);

byte b[]=new byte[is.available()];

is.read(b);

int flag=0;

try

{

String sql = "INSERT into tbl_image(image) values('" + b + "')";

System.out.println(sql);

stmt.execute(sql);

flag=1;

}

catch(Exception e)

{

System.out.println("SQL Exception : " + e);

}

if(flag==1)

{

System.out.println("Query Executed Successfully");

}

stmt.close();

}

catch(Exception e)

{

System.out.println(e);

}

out.println("The Image is Added into Database");

%>

Retrieve and display an image from and to the database

<%@page contentType="text/html"%>

<%@page pageEncoding="UTF-8"%>

<%@ page language="java" %>

<%@ page import="java.awt.image.*"%>

<%@ page import="java.io.*"%>

<%@ page import="java.sql.*"%>

<%@ page import="javax.servlet.*"%>

<%@ page import="javax.servlet.http.*"%>

<%@ page import="java.io.File"%>

<%@ page import="javax.imageio.ImageIO"%>

<%@ page import="java.awt.image.BufferedImage,java.util.*"%>

<%@ page import="java.awt.*"%>







<%

try

{

javax.servlet.http.HttpServletResponse res=null;;

int returnValue = 0;

Connection conn = null;

Statement stmt = null;

ResultSet rs = null;

InputStream in = null;

OutputStream os = null;

Blob blob = null;

String text;

text=request.getParameter("text");

Class.forName("com.mysql.jdbc.Driver");

conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/testdb","root","password");

final String query = "SELECT image FROM tablename";

conn.setAutoCommit(false);

stmt = conn.createStatement();

rs = stmt.executeQuery(query);

int i=1;

if(rs.next())

{

String len1 = rs.getString("image");

int len = len1.length();

byte [] b = new byte[len];

in = rs.getBinaryStream("image");

int index = in.read(b, 0, len);

OutputStream outImej = new FileOutputStream("C:/Documents and Settings/Desktop/photo/img"+i+".JPG");

while (index != -1)

{

outImej.write(b, 0, index);

index = in.read(b, 0, len);

System.out.println(index);

System.out.println(outImej);

}

outImej.close();

i++;

}

else

{

returnValue = 1;

}

}

catch(Exception e)

{

out.println(e);

}

%>