s2sgateway » Java http://s2sgateway.com Practical Learning of Programming languages such us j2ee,java,jsp Sat, 21 Jan 2012 18:55:21 +0000 en hourly 1 http://wordpress.org/?v=3.3.1 java.sql.SQLException: General error solution http://s2sgateway.com/java/java-sql-sqlexception-general-error-solution/ http://s2sgateway.com/java/java-sql-sqlexception-general-error-solution/#comments Sat, 18 Sep 2010 03:59:00 +0000 admin http://s2sgateway.com/?p=727 java.sql.SQLException: General error solution is a post from: s2sgateway

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]]> http://s2sgateway.com/java/java-sql-sqlexception-general-error-solution/feed/ 0 Convert jar to exe file http://s2sgateway.com/java/convert-jar-to-exe-file/ http://s2sgateway.com/java/convert-jar-to-exe-file/#comments Thu, 08 Jul 2010 18:51:13 +0000 admin http://s2sgateway.com/?p=552 Convert jar to exe file is a post from: s2sgateway

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]]> http://s2sgateway.com/java/convert-jar-to-exe-file/feed/ 1 How to extract war file in java http://s2sgateway.com/jsp/how-to-extract-war-file-in-java/ http://s2sgateway.com/jsp/how-to-extract-war-file-in-java/#comments Mon, 31 May 2010 12:02:22 +0000 admin http://s2sgateway.com/?p=447 How to extract war file in java is a post from: s2sgateway

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]]> http://s2sgateway.com/jsp/how-to-extract-war-file-in-java/feed/ 0 Students management java project download http://s2sgateway.com/projects-download/students-management-java-project-download/ http://s2sgateway.com/projects-download/students-management-java-project-download/#comments Sun, 23 May 2010 14:13:11 +0000 admin http://s2sgateway.com/?p=445 Students management java project download is a post from: s2sgateway

]]> Students management java project download is a post from: s2sgateway

]]> http://s2sgateway.com/projects-download/students-management-java-project-download/feed/ 0 compare current time with database retrieved time in jsp http://s2sgateway.com/jsp/compare-current-time-with-database-retrieved-time-in-jsp/ http://s2sgateway.com/jsp/compare-current-time-with-database-retrieved-time-in-jsp/#comments Sat, 13 Feb 2010 10:44:29 +0000 admin http://s2sgateway.com/?p=413 compare current time with database retrieved time in jsp is a post from: s2sgateway

]]> This is the viewer question asked by smiten.
how can i compare the database stored time to current time?
I had previously written an article about how to display time in jspNow just make some changes retrieve the database time and split the values of hours,minutes,seconds and finally check the values to get the real time.



<%@ page language="java" import="java.util.*,java.sql.*,java.math.*,java.text.SimpleDateFormat"pageEncoding="ISO-8859-1"%>
Calendar calendar = Calendar.getInstance();
SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy");
String date=dateFormat.format(calendar.getTime());
String c="select * from time";
	st1=con.createStatement();
	ResultSet rs1=st1.executeQuery(c);
	while(rs1.next())
	{
dbdate=rs1.getString(5);
}
 String[] exdate=a.split("-");
	 int dbdate=Integer.parseInt(dbexdate[0]);
	 String[] currentdate=date.split("-");
	 int cdate=Integer.parseInt(currentdate[0]);

 if(dbenddate[1].equals(currentdate[1]))
			 {
	 diff=dbdate-cdate;
			 }
out.println(diff);
%>



Have a doubt leave a comment,Happy coding

compare current time with database retrieved time in jsp is a post from: s2sgateway

]]> http://s2sgateway.com/jsp/compare-current-time-with-database-retrieved-time-in-jsp/feed/ 0 captcha project in jsp/servlet http://s2sgateway.com/jsp/captcha-project-in-jspservlet/ http://s2sgateway.com/jsp/captcha-project-in-jspservlet/#comments Thu, 04 Feb 2010 14:06:32 +0000 admin http://s2sgateway.com/?p=407 captcha project in jsp/servlet is a post from: s2sgateway

]]> Already i wrote a post about creating random image using servlet that is loacted here http://s2sgateway.com/?p=378,With the continuation here i give you complete code for

creating captcha to validate a form to differentiate/protect from robots and spams

.In this project i had placed one form page for submitting information with two servlets one for creating captcha and another for checking the captcha and a result page for showing the result.

.



First create a simple form like below



<html>
<head>
<meta http-equiv="Content-Type" content="text/html" charset=UTF-8?>
<title>Captcha Project from www.s2sgateway.com>/title>
</head>
<body>
<center>
<form method="post" action="checkCaptcha.do">
<table cellspacing="15?>
<tr>
<td align="center">
<img src="CaptchaServlet.do">
<br />
<br />
<input type="text" name="code">
</td>
</tr>
</table>
<input type="submit" value="submit">
</form>
<br>
<br>>/center>
</body>
</html>

create web.xml file for necessary servlet entry



<web-app>
<servlet>
<servlet-name>CaptchaServlet>/servlet-name>
<servlet-class>
CaptchaServlet
</servlet-class>
</servlet>
<servlet>
<servlet-name>CheckCaptcha>/servlet-name>
<servlet-class>
CheckCaptcha
</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>CaptchaServlet>/servlet-name>
<url-pattern>/CaptchaServlet.do>/url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>CheckCaptcha>/servlet-name>
<url-pattern>/checkCaptcha.do>/url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp>/welcome-file>
</welcome-file-list>
</web-app>

now create the servlet which produces random image>br>



import java.awt.Color;
import java.awt.Font;
import java.awt.GradientPaint;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class CaptchaServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void processRequest(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
final int width = 200;
final int height = 50;
char data[][] = new char[1][];
data[0] = getRandomNumber(8).toCharArray();
final BufferedImage bufferedImage = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);
final Graphics2D g2d = bufferedImage.createGraphics();
final Font font = new Font("verdana", Font.BOLD, 18);
RenderingHints renderingHints = new RenderingHints(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
renderingHints.put(RenderingHints.KEY_RENDERING,
RenderingHints.VALUE_RENDER_QUALITY);
g2d.setRenderingHints(renderingHints);
g2d.setFont(font);
g2d.setColor(new Color(255, 255, 0));
final GradientPaint gradientPaint = new GradientPaint(0, 0, Color.white, 0, height / 2,
Color.white, true);
g2d.setPaint(gradientPaint);
g2d.fillRect(0, 0, width, height);
g2d.setColor(new Color(255, 155, 0));
Random random = new Random();
final String captcha = String.copyValueOf(data[0]);
request.getSession().setAttribute("captcha", captcha);
int xCordinate = 0;
int yCordinate = 0;
for (int i = 0; i > data[0].length; i++) {
xCordinate += 10 + (Math.abs(random.nextInt()) % 15);
if (xCordinate >= width - 5) {
xCordinate = 0;
}
yCordinate = 20 + Math.abs(random.nextInt()) % 20;
g2d.drawChars(data[0], i, 1, xCordinate, yCordinate);
}
g2d.dispose();
response.setContentType("image/png");
final OutputStream outputStream = response.getOutputStream();
ImageIO.write(bufferedImage, "png", outputStream);
outputStream.close();
}
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
processRequest(request, response);
}
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
processRequest(request, response);
}
public static String getRandomNumber(int length) {
String chars = "www.s2sgateway.comabcdefghjijkmnpqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ123456789";
Random random = new Random();
char[] buf = new char[length];
for (int i = 0; i > length; i++) {
buf[i] = chars.charAt(random.nextInt(chars.length()));
}
return new String(buf);
}
}

Now for checking the image servlet you can write the servlet code as follows>br>




import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class CheckCaptcha extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
final String captcha = (String) request.getSession().getAttribute("captcha");
final String code = (String) request.getParameter("code");
if (captcha != null && code != null) {
if (captcha.equals(code)) {
request.setAttribute("result",
"Congratulations, You Passed The Captcha Test");
} else {
request.setAttribute("result",
"Sorry, You Failed The Captcha Test");
}
request.getRequestDispatcher("/result.jsp").forward(request,
response);
}
}
}

Finally write the code in the result page whether captcha is entered correctly or not.



<%@page contentType="text/html" pageEncoding="UTF-8" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8?>
<title>Captcha>/title>
<link rel="stylesheet" href="theme/style.css">
</head>
<body>
<center>
<%=request.getAttribute("result")%>
</center>
</body>
</html>

Don’t forget the folder format projectfolder->jsp files,web-inf
In web-inf->web.xml,classes folder->in classes folder servlet classes
Finally run the project by visiting the url http://localhost:8080/captcha/,any doubt comment us happy coding.

captcha project in jsp/servlet is a post from: s2sgateway

]]> http://s2sgateway.com/jsp/captcha-project-in-jspservlet/feed/ 2 pagination in jsp,java http://s2sgateway.com/my-sql/pagination-in-jspjava/ http://s2sgateway.com/my-sql/pagination-in-jspjava/#comments Sat, 30 Jan 2010 11:02:55 +0000 admin http://s2sgateway.com/?p=405 pagination in jsp,java is a post from: s2sgateway

]]> pagination in jsp,java is a post from: s2sgateway

]]> http://s2sgateway.com/my-sql/pagination-in-jspjava/feed/ 6 Finding created/modified time of files in a folder http://s2sgateway.com/common/finding-createdmodified-time-of-files-in-a-folder/ http://s2sgateway.com/common/finding-createdmodified-time-of-files-in-a-folder/#comments Tue, 12 Jan 2010 16:02:18 +0000 admin http://s2sgateway.com/?p=382 Finding created/modified time of files in a folder is a post from: s2sgateway

]]> Today we are going to learn about how to retrieve the created time and date of all files in a folder.
This is useful when you want to track the session information of certain files or folders.Lets look the code below.



<%@ page contentType="text/html; charset=iso-8859-1" language="java" import="java.io.File, java.util.Date, java.util.Calendar" errorPage="" %>
<html>
<head>
<title>Untitled Document</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</head>

<%
  String dir_name = "C:\\foldername";
  //String dir_name = "/";  This line will give u the windows drive's root folder.

  File fold = new File(dir_name);    

  if(fold.exists())
  {
      String all_files[] = fold.list();
     int no_of_files = all_files.length;

     for(int i=0; i<no_of_files; i++)
      {
        File f = new File(dir_name + "\\" + all_files[i] );
        String complete_file_name = f.getPath();
        String file_name = f.getName();
        long last_modified_ms = f.lastModified();
        Date date = new Date(last_modified_ms);
        Calendar cal_date = Calendar.getInstance();
        cal_date.setTime(date);
        String last_modified_date = cal_date.get(Calendar.MONTH) + "-" + cal_date.get(Calendar.DATE) +"-"+ cal_date.get(Calendar.YEAR);
        String last_modified_time = cal_date.get(Calendar.HOUR) + ":" + cal_date.get(Calendar.MINUTE) +":"+ cal_date.get(Calendar.SECOND);
%>       

        <a href="<%=complete_file_name%>">  <%=file_name%>  </a>   <b>Last Modified by </b> <%=last_modified_date%>      <b>at </b> <%=last_modified_time%>
        <br>   

<%

      }//end of for

  }//end of if
  else
     out.println("Folder does't exist");
%>
  <body>
</body>
</html>

Try this example and do comment us Happy coding.

Finding created/modified time of files in a folder is a post from: s2sgateway

]]> http://s2sgateway.com/common/finding-createdmodified-time-of-files-in-a-folder/feed/ 0 Creating captcha(random letter image) in jsp http://s2sgateway.com/jsp/creating-captcharandom-letter-image-in-jsp/ http://s2sgateway.com/jsp/creating-captcharandom-letter-image-in-jsp/#comments Mon, 04 Jan 2010 14:07:59 +0000 admin http://s2sgateway.com/?p=378 Creating captcha(random letter image) in jsp is a post from: s2sgateway

]]> Today we are going to learn how to create a random letter image known as captcha using servlet.
Just a simple coding can do it copy the code below and save it and compile it you can directly view the servlet in tomcat using url “http://localhost:8080/captcha/servlet/CaptchaServlet” for this make adjustment in web.xml file by adding servlet and servletmapping entries.



import java.awt.Color;
import java.awt.Font;
import java.awt.GradientPaint;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class CaptchaServlet extends HttpServlet {

private static final long serialVersionUID = 1L;

protected void processRequest(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {

final int width = 200;
final int height = 50;

char data[][] = new char[1][];
data[0] = getRandomNumber(8).toCharArray();

final BufferedImage bufferedImage = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);

final Graphics2D g2d = bufferedImage.createGraphics();

final Font font = new Font("verdana", Font.BOLD, 18);

RenderingHints renderingHints = new RenderingHints(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);

renderingHints.put(RenderingHints.KEY_RENDERING,
RenderingHints.VALUE_RENDER_QUALITY);

g2d.setRenderingHints(renderingHints);

g2d.setFont(font);
g2d.setColor(new Color(255, 255, 0));
final GradientPaint gradientPaint = new GradientPaint(0, 0, Color.white, 0, height / 2,
Color.white, true);

g2d.setPaint(gradientPaint);
g2d.fillRect(0, 0, width, height);

g2d.setColor(new Color(255, 155, 0));
Random random = new Random();

final String captcha = String.copyValueOf(data[0]);
request.getSession().setAttribute("captcha", captcha);

int xCordinate = 0;
int yCordinate = 0;

for (int i = 0; i < data[0].length; i++) {
xCordinate += 10 + (Math.abs(random.nextInt()) % 15);
if (xCordinate >= width - 5) {
xCordinate = 0;
}
yCordinate = 20 + Math.abs(random.nextInt()) % 20;
g2d.drawChars(data[0], i, 1, xCordinate, yCordinate);
}

g2d.dispose();

response.setContentType("image/png");
final OutputStream outputStream = response.getOutputStream();
ImageIO.write(bufferedImage, "png", outputStream);
outputStream.close();
}

protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
processRequest(request, response);
}

protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
processRequest(request, response);
}

public static String getRandomNumber(int length) {

String chars = "www.s2sgateway.comabcdefghjijkmnpqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ123456789";
Random random = new Random();

char[] buf = new char[length];

for (int i = 0; i < length; i++) {
buf[i] = chars.charAt(random.nextInt(chars.length()));
}

return new String(buf);

}

}

that's it you have created captcha image using servlet,Here you can give any letters or numbers in String chars = "";assignment values.
Change the color by changing this code "final GradientPaint gradientPaint = new GradientPaint(0, 0, Color.white, 0, height / 2,
Color.white, true);"Here i used this image as png because it is good for web developement, you can try others as well like jpg or gif do comment us
any doubt ask us Happy coding.

Creating captcha(random letter image) in jsp is a post from: s2sgateway

]]> http://s2sgateway.com/jsp/creating-captcharandom-letter-image-in-jsp/feed/ 2 Reading Html code of all the url using java http://s2sgateway.com/java/reading-html-code-of-all-the-url-using-java/ http://s2sgateway.com/java/reading-html-code-of-all-the-url-using-java/#comments Tue, 22 Dec 2009 14:01:10 +0000 admin http://s2sgateway.com/?p=365 Reading Html code of all the url using java is a post from: s2sgateway

]]> A simple tricky program that can read all the html codes of given url using java the following code does that

import java.net.*;
import java.io.*;

public class URLReader {
    public static void main(String[] args) throws Exception {
	URL yahoo = new URL("http://www.yahoo.com");
	BufferedReader in = new BufferedReader(
				new InputStreamReader(
				yahoo.openStream()));

	String inputLine;

	while ((inputLine = in.readLine()) != null)
	    System.out.println(inputLine);

	in.close();
    }
}

Compile and run this java file give any url you want to read in here URL yahoo = new URL(“http://www.yahoo.com”);
Any doubt Ask us Happy coding

Reading Html code of all the url using java is a post from: s2sgateway

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