How To find hidden Files in Java

Here in this blog we will explain how to find hidden file in system can be linux or windows using File operation in java 

As per Java Document method details are below 

• isHidden

  public boolean isHidden()

  Tests whether the file named by this abstract pathname is a hidden file. The exact definition of hidden is system-dependent. On UNIX systems, a file is considered to be hidden if its name begins with a period character ('.'). On Microsoft Windows systems, a file is considered to be hidden if it has been marked as such in the filesystem.

  Returns:

  true if and only if the file denoted by this abstract pathname is hidden according to the conventions of the underlying platform

  Throws:

  SecurityException - If a security manager exists and its SecurityManager.checkRead(java.lang.String) method denies read access to the file

  
  

  Sample Code :

  
  

  
  

  
  

  
  

         
  
  package com.learnjavabyanand;
  
  import java.io.*;
  
  /**
   * @author Anand
   *
   */
  public class CheckHideenFiles {
   public static void main(String[] args) {
    try {
     File file = new File("C:/users/ananddw/codeDetails.txt");
     if (file.isHidden()) {
      System.out.println(file.getName() + " is Hidden File");
     } else {
      System.out.println(file.getName() + " File is not Hidden ");
     }
    } catch (Exception e) {
     e.getMessage();
    }
  
   }
  
  }
  
   
   

How to Create Whole Path Automatically and write into File In Java

        File file = new File("/home/anand/Desktop/filename.html");
        file.getParentFile().mkdirs();
        FileWriter writer = new FileWriter(file);
       
        bw = new BufferedWriter(writer);
        PrintWriter  out = new PrintWriter(bw);
        out.println("<h4>Welcome in Bangalore</h4>");
        out.close();

How Session Managment Works in servlet/jsp

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.sql.*;

/**
 *
 * @author pandey
 */
public class Registration extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        PrintWriter out = response.getWriter();
        HttpSession hs = request.getSession();

        /*================== Get First Form Data  =======================*/
        String id = request.getParameter("fno");
        if (id.equals("1")) {

            String name = request.getParameter("name");
            String fname = request.getParameter("fname");
            String mname = request.getParameter("mname");

            hs.setAttribute("name", name);
            hs.setAttribute("fname", fname);
            hs.setAttribute("mname", mname);

            response.sendRedirect("./index1.jsp");

        }
        if (id.equals("2")) {

            String contact = request.getParameter("contact");
            String email = request.getParameter("email");
            String adds = request.getParameter("adds");

            hs.setAttribute("contact", contact);
            hs.setAttribute("email", email);
            hs.setAttribute("adds", adds);

            response.sendRedirect("./index2.jsp");
        }
        if (id.equals("3")) {

            String qual = request.getParameter("qual");
            String per = request.getParameter("per");

            String name = (String) hs.getAttribute("name");
            String fname = (String) hs.getAttribute("fname");
            String mname = (String) hs.getAttribute("mname");

            String contact = (String) hs.getAttribute("contact");
            String email = (String) hs.getAttribute("email");
            String adds = (String) hs.getAttribute("adds");

            try {
                /*============================== Store Data into DataBase ==============*/

                Connection c = null;
                PreparedStatement stmt = null;

                Class.forName("org.postgresql.Driver");
                c = DriverManager.getConnection("jdbc:postgresql://localhost:5432/Anand", "postgres", "password");
                System.out.println("Opened database successfully");
                stmt = c.prepareStatement("insert into adhar values(?,?,?,?,?,?,?,?)");
                stmt.setString(1, name);
                stmt.setString(2, fname);
                stmt.setString(3, mname);
                stmt.setString(4, contact);
                stmt.setString(5, email);
                stmt.setString(6, adds);
                stmt.setString(7, qual);
                stmt.setString(8, per);

                int i = stmt.executeUpdate();
                if (i != 0) {
                    out.println("<h2>registration Sucess</h2>");
                } else {
                    out.println("Registration Failed");
                }
                c.close();
                stmt.close();

            } catch (Exception e) {
                System.out.println("Exception Occur on Catch Block " + e.getMessage());
                //e.printStackTrace();
            }
        }

    }
}


==============index.jsp ===========


<%--
    Document   : index
    Created on : Mar 15, 2016, 4:15:12 PM
    Author     : ananddw
--%>

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>IRCTC  Page</title>
    </head>
    <body bgcolor="blue" style="padding-left: 45%; padding-right: 10%;padding-top: 8%;">
        <form action="./Reg">
            <table border="5">
                <pre>
    <tr><td>
           Name : <input type="text" name="name" id="name"/>
    </td></tr>
    </br></br>
    <tr><td>
            Father Name : <input type="text" name="fname" id="fname"/>
    </td></tr>
    </br></br>
    <tr><td>           Mother Name : <input type="text" name="mname" id="mname"/>
    </td></tr>

    </br></br>
    <tr><td>

              <input type="submit" name="Submit" value="Next>>"/>
    </td></tr>

<input type="hidden" name="fno" value="1"/>

                </pre>
            </table>
        </form>
    </body>
</html>
=====index1.jsp============
<%--
    Document   : index1
    Created on : Mar 15, 2016, 4:24:26 PM
    Author     : ananddw
--%>

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>IRCTC Page</title>
    </head>
    <body bgcolor="blue" style="padding-left: 45%; padding-right: 10%;padding-top: 8%;">
        <form action="./Reg" >
            <table border="5">


                <tr><td>
                        Contact : <input type="text" name="contact" id="contact"/>
                    </td></tr>
                <br></br>  
                <tr><td>
                        Email : <input type="text" name="email" id="email"/>
                    </td></tr>
                <br></br>
                <tr><td>
                        Address: <textarea rows="5" cols="15" name="adds"></textarea>
                    </td></tr>
                <br></br>        
                <tr><td>        
                        <input type="submit" name="Submit" value="Next>>"/>

                    </td></tr>
                <br></br>
                <input type="hidden" name="fno" value="2"/>

            </table>


        </form>
    </body>
</html>
============index2.jsp=====
<%--
    Document   : index2
    Created on : Mar 15, 2016, 4:30:46 PM
    Author     : ananddw
--%>

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>IRCTC Page</title>
    </head>
    <body bgcolor="blue" style="padding-left: 45%; padding-right: 10%;padding-top: 8%;">
        <form action="./Reg">
            <table border="5">

                <tr><td>  
                        Qualification :<input type="text" name="qual" id="qual"/>
                    </td></tr>
                <br></br>
                <tr><td>
                        Percentage: <input type="text" name="per" id="per"/>
                    </td></tr>
                <br></br>
                <tr><td>
                        <input type="Submit" name="Submit" value="Submit"/>
                    </td></tr>
                <br></br>
            </table>
            <input type="hidden" name="fno" value="3"/>

        </form>
    </body>
</html>
=================web.xml===========

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
    <servlet>
        <servlet-name>Registration</servlet-name>
        <servlet-class>Registration</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>Registration</servlet-name>
        <url-pattern>/Reg</url-pattern>
    </servlet-mapping>
    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>
</web-app>



For any suggestion please drop a mail on : ananddwivedi92@gmail.com

Java Experiance InterView Questions and answer

--> Example of SingleTone in java 

public final class SingleTone {
   
    /**
     * @author anand
     *
     */
   
   
    public static SingleTone single;
    //Can be act as SingleTone or make constructor as private
   
    private SingleTone(){}
   
    public static synchronized SingleTone getInstance(){
       
        if(single==null){
           
            single=new SingleTone();
        }
        return single;
    }
   

}

--> What is difference between StringBuffer and StringBuilder in Java ?

# Stringbuffer methods are synchronized while StringBuilder is non synchronized. See StringBuilder vs StringBuffer for more differences.
 # StringBuffer as slow in performance since Thread Safe whereas StringBuilder in faster .

Scheduler JOB in java

package com..scheduler;

import static org.quartz.CronScheduleBuilder.dailyAtHourAndMinute;
import java.util.Calendar;
import org.quartz.Job;
import org.quartz.JobBuilder;
import org.quartz.JobDetail;
import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;
import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.Trigger;
import org.quartz.TriggerBuilder;
import org.quartz.impl.StdSchedulerFactory;


public class SchedulerTest implements Job {

    public static void main(String[] args) {

        int HOUR_OF_DAY = Integer.parseInt("20");
        int MINUTE_OF_HOUR = Integer.parseInt("10");


        Trigger trigger1 = TriggerBuilder.newTrigger().withIdentity("test trigger1", "group1").withSchedule(dailyAtHourAndMinute(08, 00)).build();
        Trigger trigger2 = TriggerBuilder.newTrigger().withIdentity("test trigger2", "group1").withSchedule(dailyAtHourAndMinute(20, 01)).build();
        Trigger trigger3 = TriggerBuilder.newTrigger().withIdentity("test trigger3", "group1").withSchedule(dailyAtHourAndMinute(23, 10)).build();

        try {
            Scheduler scheduler = new StdSchedulerFactory().getScheduler();
            scheduler.start();

            JobDetail job1 = JobBuilder.newJob(NewsLetterSchedulerTest.class).withIdentity("test job1", "group1").build();
            scheduler.scheduleJob(job1, trigger1);

            JobDetail job2 = JobBuilder.newJob(NewsLetterSchedulerTest.class).withIdentity("test job2", "group1").build();
            scheduler.scheduleJob(job2, trigger2);

            JobDetail job3 = JobBuilder.newJob(NewsLetterSchedulerTest.class).withIdentity("test job3", "group1").build();
            scheduler.scheduleJob(job3, trigger3);

        } catch (SchedulerException e) {
            e.printStackTrace();
        } catch (Throwable e) {
            e.printStackTrace();
        }
    }
public boolean getValue(){
  System.out.println("Simple Method invoked from Scheduler");
return true;
}
    @Override
    public void execute(JobExecutionContext context) throws JobExecutionException {
        SchedulerTest  scheduler=new SchedulerTest ();
scheduler.getValue();
    }
}

PS: Make sure that required jars your have to add to run above code

How to write Scheduler in Java

import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

/**
 * This Class is Used to Run Every after 15 min
 *
 * @author ananddw
 **/
public class TestScheduler{

    public static void main(String[] args) {
        new TestScheduler().start();
    }

    public void start() {

        System.out.println(" scheduler starts");

        Executors.newSingleThreadScheduledExecutor().scheduleWithFixedDelay(new Runnable() {
            @Override
            public void run() {
                try {
                    //Need to Call Your Method which will execute every after 15 min
                    System.out.println(new java.util.Date());
                } catch (Throwable e) {
                    System.out.println("--Error in  Schduler--");
                    e.printStackTrace();
                }
            }
        }, 0, 15, TimeUnit.MINUTES);
    }
}

how to get src value from normal Text in javascript

<html>
<head>
</head>
<title>|| Video Uploader || </title>
<body>
<input type="text" id="video_url" name="video_url" value="<iframe   width='420' height='315'    src='https://www.youtube.com/embed/XGSy3_Czz8k'></iframe>"  />
<button id = "opener" onclick="insertURL()">Show URL </button>

<script type="text/javascript">
<!-- If User's Provide direct URL or Full iframe innerhtml-->
    function insertURL(){
        var ishare_url = document.getElementById("video_url").value;
       
        if(undefined!==ishare_url.split('src=')[1]){
        var src = ishare_url.split('src=')[1].split(/[ >]/)[0];
        if(src){
            var decode_ishare_url = decodeURI(src.trim());
            var replace_String = decode_ishare_url.replace(/%22/g, '');
            var replaceQuotes = replace_String.replace(/['"]+/g, '');
            document.getElementById("video_url").value = replaceQuotes;//Assign updated value
           
            }
        }else {
            if (ishare_url){
            var decode_ishare_url = decodeURI(ishare_url.trim());
            var replace_String = decode_ishare_url.replace(/%22/g, '');
            var replaceQuotes = replace_String.replace(/['"]+/g, '');

            document.getElementById("video_url").value = replaceQuotes;//Assign updated value
            }
            }
            alert("SRC ::    "+document.getElementById("video_url").value);
    }   
   
    function clearFieldValue() {
    // Clear urls Fields here
    document.getElementById("video_url").value = "";
}
window.onload = clearFieldValue;       
</script>
</body>
</html>