JAVA EE: January 2017

Monday, 30 January 2017

Java Tutorial: Java Synchronization (Why we use Synchronization[Bank] | Synchronization in java)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=Pr7NlI7nbFg&list=UUhwKlOVR041tngjerWxVccw

Click the below Image to Enlarge

Java Tutorial: Java Synchronization (Why we use Synchronization[Bank] | Synchronization in java)

BankAccount.java

public class BankAccount
{

    private int accountNumber;
    private double accountBalance;
    
    private AccountDAO dao;

    public synchronized boolean deposit(double amount)
    {
        double newAccountBalance;
        /*
         * Get the current balance from DB table.
         */
        accountBalance = dao.getCurrentAccountBalance(accountNumber);
        
        if (amount < 0.0)
        {
            /*
             * Can not deposit a negative amount.
             */
            return false; 
        }

        else
        {
            newAccountBalance = accountBalance + amount;
            /*
             * Update the new balance in the DB table.
             */         
            dao.updateAccountBalance(newAccountBalance);
            return true;
        }

    }
}

AccountDAO.java

public class AccountDAO
{

    public double getCurrentAccountBalance(int accountNumber)
    {
        /*
         * Code to get the current balance from DB table.
         */
        return 0;
    }

    public void updateAccountBalance(double newAccountBalance)
    {
        /*
         * Code to update the new balance in the DB table.
         */ 
        
    }

}

Click the below link to download the code:
https://sites.google.com/site/ramj2eev1/home/javabasics/SynchronizationDemo_Bank_App.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/SynchronizationDemo_Bank_App/SynchronizationDemo

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/28b772df8f5b4b9e60fd873726243fc258cd34a2/BasicJava/SynchronizationDemo_Bank_App/SynchronizationDemo/?at=master

See also:

All JavaEE Viedos Playlist

All JavaEE Viedos

All JAVA EE Links

Servlets Tutorial

All Design Patterns Links

JDBC Tutorial

Java Collection Framework Tutorial

JAVA Tutorial

Kids Tutorial

Java Tutorial: Java Synchronization (Java Synchronization | Synchronization in java) - Playlist

Click here to watch in Youtube :
https://www.youtube.com/watch?v=xTBu6iXL8LM&list=PLmCsXDGbJHdhLWV0-HM8eGIa0je7nZJ5I
See also:

All JavaEE Viedos Playlist

All JavaEE Viedos

All JAVA EE Links

Servlets Tutorial

All Design Patterns Links

JDBC Tutorial

Java Collection Framework Tutorial

JAVA Tutorial

Kids Tutorial

Java Tutorial: Java Synchronization (Why we use Synchronization | Synchronization in java)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=Y9vFftRKUEY&list=UUhwKlOVR041tngjerWxVccw

Click the below Image to Enlarge

Java Tutorial: Java Synchronization (Why we use Synchronization | Synchronization in java)

Java Tutorial: Java Synchronization (Java Synchronization | Synchronization in java)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=xTBu6iXL8LM&list=UUhwKlOVR041tngjerWxVccw

Click the below Image to Enlarge

Java Tutorial: Java Synchronization (Java Synchronization | Synchronization in java)

Java Tutorial: Java Runtime class (gc method)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=AHhIMs3HAyI&list=UUhwKlOVR041tngjerWxVccw

RuntimeDemo.java

import java.io.IOException;

public class RuntimeDemo
{

    public static void main(String[] args) throws IOException
    {
        /*
         * Returns the runtime object associated with the
         * current Java application.
         */
        Runtime runtime = Runtime.getRuntime();

        System.out.println("Runs the Gargage collector..");
        /*
         * Runs the garbage collector.
         * 
         * Calling this method suggests that the Java
         * virtual machine expend effort toward recycling
         * unused objects in order to make the memory they
         * currently occupy available for quick reuse. When
         * control returns from the method call, the virtual
         * machine has made its best effort to recycle all
         * discarded objects.
         * 
         * The name gc stands for "garbage collector". The
         * virtual machine performs this recycling process
         * automatically as needed, in a separate thread,
         * even if the gc method is not invoked explicitly.
         * 
         * The method System.gc() is the conventional and
         * convenient means of invoking this method.
         */
        runtime.gc();

    }

}

Output

Runs the Gargage collector..

Click the below link to download the code:
https://sites.google.com/site/ramj2eev1/home/javabasics/RuntimeDemo_GC_App.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/RuntimeDemo_GC_App

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/28b772df8f5b4b9e60fd873726243fc258cd34a2/BasicJava/RuntimeDemo_GC_App/?at=master

See also:

All JavaEE Viedos Playlist

All JavaEE Viedos

All JAVA EE Links

Servlets Tutorial

All Design Patterns Links

JDBC Tutorial

Java Collection Framework Tutorial

JAVA Tutorial

Kids Tutorial

Java Tutorial: Java Runtime class (halt method)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=U0h2VimMOkQ&list=UUhwKlOVR041tngjerWxVccw

RuntimeDemo.java

import java.io.IOException;

/*
 * public void halt(int status)
 * 
 * Parameters: 
 * -----------
 * 
 * status - Termination status. By convention, a nonzero
 * status code indicates abnormal termination.
 */
public class RuntimeDemo
{

    public static void main(String[] args) throws IOException
    {
        /*
         * Returns the runtime object associated with the
         * current Java application.
         */
        Runtime runtime = Runtime.getRuntime();

        System.out.println("Before halt method is called..");
        /*
         * Forcibly terminates the currently running Java
         * virtual machine.
         * 
         * This method should be used with extreme caution.
         * Unlike the exit method, this method does not
         * cause shutdown hooks to be started and does not
         * run uninvoked finalizers if finalization-on-exit
         * has been enabled. If the shutdown sequence has
         * already been initiated then this method does not
         * wait for any running shutdown hooks or finalizers
         * to finish their work.
         */
        runtime.halt(0);
        System.out.println("After halt method is called..");
    }

}

Output

Before halt method is called..

Click the below link to download the code:
https://sites.google.com/site/ramj2eev1/home/javabasics/RuntimeDemo_halt_App.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/RuntimeDemo_halt_App

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/28b772df8f5b4b9e60fd873726243fc258cd34a2/BasicJava/RuntimeDemo_halt_App/?at=master

See also:

All JavaEE Viedos Playlist

All JavaEE Viedos

All JAVA EE Links

Servlets Tutorial

All Design Patterns Links

JDBC Tutorial

Java Collection Framework Tutorial

JAVA Tutorial

Kids Tutorial

Java Tutorial: Java Runtime class (exec(String command,String[] envp,File dir) method)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=-AzVJNru9Ls&list=UUhwKlOVR041tngjerWxVccw

RuntimeDemo.java

import java.io.File;
import java.io.IOException;

/*
 * public Process exec(String command, String[] envp,
 *                              File dir) throws IOException
 * 
 * Parameters: 
 * -----------
 * 
 * command - a specified system command.
 * 
 * envp - array of strings, each element of which has
 * environment variable settings in the format
 * name=value, or null if the subprocess should inherit
 * the environment of the current process.
 * 
 * dir - the working directory of the subprocess, or
 * null if the subprocess should inherit the working
 * directory of the current process.
 */

public class RuntimeDemo
{

    public static void main(String[] args) throws IOException
    {
        /*
         * Returns the runtime object associated with the
         * current Java application.
         */
        Runtime runtime = Runtime.getRuntime();

        /*
         * Create a file with the working directory we wish
         */
        File dir = new File("D:/Work/");

        /*
         * Executes the specified string command in a
         * separate process with the specified environment
         * and working directory.
         * 
         * It will open a new notepad.
         */
        Process process = runtime.exec("notepad.exe", null, dir);
        System.out.println("is process alive = " + process.isAlive());
    }

}

Output

is process alive = true

Click the below link to download the code:
https://sites.google.com/site/ramj2eev1/home/javabasics/RuntimeDemo_exec_cmd_envp_dir_App.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/RuntimeDemo_exec_cmd_envp_dir_App

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/28b772df8f5b4b9e60fd873726243fc258cd34a2/BasicJava/RuntimeDemo_exec_cmd_envp_dir_App/?at=master

See also:

All JavaEE Viedos Playlist

All JavaEE Viedos

All JAVA EE Links

Servlets Tutorial

All Design Patterns Links

JDBC Tutorial

Java Collection Framework Tutorial

JAVA Tutorial

Kids Tutorial

Java Tutorial: Java Runtime class (exec(String command,String[] envp) method)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=BEARNZg4-SM&list=UUhwKlOVR041tngjerWxVccw

RuntimeDemo.java

import java.io.IOException;

/*
 * public Process exec(String command, String[] envp)
 *                                      throws IOException
 *
 * Parameters:
 * -----------
 *
 * command - a specified system command.
 *
 * envp - array of strings, each element of which has
 * environment variable settings in the format
 * name=value, or null if the subprocess should inherit
 * the environment of the current process.
 */
public class RuntimeDemo
{

    public static void main(String[] args) throws IOException
    {
        /*
         * Returns the runtime object associated with the
         * current Java application.
         */
        Runtime runtime = Runtime.getRuntime();

        /*
         * Executes the specified string command in a
         * separate process with the specified environment.
         *
         * It will open a new notepad.
         */
        Process process = runtime.exec("notepad.exe",null);
        System.out.println("is process alive = " + process.isAlive());
    }

}

Output

is process alive = true

Click the below link to download the code:
https://sites.google.com/site/ramj2eev1/home/javabasics/RuntimeDemo_exec_cmd_envp_App.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/RuntimeDemo_exec_cmd_envp_App

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/28b772df8f5b4b9e60fd873726243fc258cd34a2/BasicJava/RuntimeDemo_exec_cmd_envp_App/?at=master

See also:

All JavaEE Viedos Playlist

All JavaEE Viedos

All JAVA EE Links

Servlets Tutorial

All Design Patterns Links

JDBC Tutorial

Java Collection Framework Tutorial

JAVA Tutorial

Kids Tutorial

Java Tutorial: Java Runtime class (exec(String[] cmdarray,String[] envp,File dir) method)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=Irfb6Fru4XQ&list=UUhwKlOVR041tngjerWxVccw

RuntimeDemo.java

import java.io.File;
import java.io.IOException;

/*
 * public Process exec(String[] cmdarray, String[] envp,
 *                              File dir) throws IOException
 * 
 * Parameters: 
 * -----------
 * 
 * cmdarray - array containing the command to call and
 * its arguments.
 * 
 * envp - array of strings, each element of which has
 * environment variable settings in the format
 * name=value, or null if the subprocess should inherit
 * the environment of the current process.
 * 
 * dir - the working directory of the subprocess, or
 * null if the subprocess should inherit the working
 * directory of the current process.
 */
public class RuntimeDemo
{

    public static void main(String[] args) throws IOException
    {

        String[] cmdArray = new String[2];

        cmdArray[0] = "notepad.exe";
        cmdArray[1] = "Hello.txt";

        System.out.println(
                "Executing notepad.exe and opening Hello.txt");

        /*
         * Returns the runtime object associated with the
         * current Java application.
         */
        Runtime runtime = Runtime.getRuntime();

        File dir = new File("D:/work");
        /*
         * Executes the specified string command in a
         * separate process with the specified environment
         * and working directory.
         * 
         * Returns: A new Process object for managing the
         * subprocess
         */
        Process process = runtime.exec(cmdArray, null, dir);

        System.out.println("is process alive = " + process.isAlive());
        System.out.println(cmdArray[1] + " should now open.");
    }

}

Output

Executing notepad.exe and opening Hello.txt
is process alive = true
Hello.txt should now open.

Click the below link to download the code:
https://sites.google.com/site/ramj2eev1/home/javabasics/RuntimeDemo_exec_cmdarray_envp_dir_App.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/RuntimeDemo_exec_cmdarray_envp_dir_App

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/28b772df8f5b4b9e60fd873726243fc258cd34a2/BasicJava/RuntimeDemo_exec_cmdarray_envp_dir_App/?at=master

See also:

All JavaEE Viedos Playlist

All JavaEE Viedos

All JAVA EE Links

Servlets Tutorial

All Design Patterns Links

JDBC Tutorial

Java Collection Framework Tutorial

JAVA Tutorial

Kids Tutorial

Java Tutorial: Java Runtime class (exec(String[] cmdarray, String[] envp) method)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=KrGPHOtlq9U&list=UUhwKlOVR041tngjerWxVccw

RuntimeDemo.java

import java.io.IOException;

/*
 * public Process exec(String[] cmdarray, String[] envp)
 *                                      throws IOException
 * 
 * Parameters: 
 * -----------
 * 
 * cmdarray - array containing the command to call and
 * its arguments. 
 * 
 * envp - array of strings, each element
 * of which has environment variable settings in the
 * format name=value, or null if the subprocess should
 * inherit the environment of the current process.
 */

public class RuntimeDemo
{

    public static void main(String[] args) throws IOException
    {

        String[] cmdArray = new String[2];

        cmdArray[0] = "notepad.exe";
        cmdArray[1] = "Hello.txt";

        System.out.println("Executing notepad.exe and opening Hello.txt");

        /*
         * Returns the runtime object associated with the
         * current Java application.
         */
        Runtime runtime = Runtime.getRuntime();

        /*
         * Executes the specified command and arguments in a
         * separate process with the specified environment.
         * 
         * Returns: A new Process object for managing the
         * subprocess
         */
        Process process = runtime.exec(cmdArray, null);

        System.out.println("is process alive = " + process.isAlive());
        System.out.println(cmdArray[1] + " should now open.");
    }

}

Output

Executing notepad.exe and opening Hello.txt
is process alive = true
Hello.txt should now open.

Click the below link to download the code:
https://sites.google.com/site/ramj2eev1/home/javabasics/RuntimeDemo_exec_cmdarray_envp_App.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/RuntimeDemo_exec_cmdarray_envp_App

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/28b772df8f5b4b9e60fd873726243fc258cd34a2/BasicJava/RuntimeDemo_exec_cmdarray_envp_App/?at=master

See also:

All JavaEE Viedos Playlist

All JavaEE Viedos

All JAVA EE Links

Servlets Tutorial

All Design Patterns Links

JDBC Tutorial

Java Collection Framework Tutorial

JAVA Tutorial

Kids Tutorial

Java Tutorial: Java Runtime class (exec(String[] cmdarray) method)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=dW75MCvPRtI&list=UUhwKlOVR041tngjerWxVccw

RuntimeDemo.java

import java.io.IOException;

/*
 * public Process exec(String[] cmdarray) throws
 *                                      IOException
 * 
 * Parameters: 
 * -----------
 * 
 * cmdarray - array containing the command to call and
 * its arguments.
 */
public class RuntimeDemo
{

    public static void main(String[] args) throws IOException
    {

        String[] cmdArray = new String[2];

        cmdArray[0] = "notepad.exe";
        cmdArray[1] = "Hello.txt";

        System.out.println("Executing notepad.exe and opening Hello.txt");

        /*
         * Returns the runtime object associated with the
         * current Java application.
         */
        Runtime runtime = Runtime.getRuntime();

        /*
         * Executes the specified command and arguments in a
         * separate process.
         * 
         * Returns: A new Process object for managing the
         * subprocess
         */
        Process process = runtime.exec(cmdArray);

        System.out.println("is process alive = " + process.isAlive());
        System.out.println(cmdArray[1] + " should now open.");
    }

}

Output

Executing notepad.exe and opening Hello.txt
is process alive = true
Hello.txt should now open.

Click the below link to download the code:
https://sites.google.com/site/ramj2eev1/home/javabasics/RuntimeDemo_exec_cmdarray_App.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/RuntimeDemo_exec_cmdarray_App

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/28b772df8f5b4b9e60fd873726243fc258cd34a2/BasicJava/RuntimeDemo_exec_cmdarray_App/?at=master

See also:

All JavaEE Viedos Playlist

All JavaEE Viedos

All JAVA EE Links

Servlets Tutorial

All Design Patterns Links

JDBC Tutorial

Java Collection Framework Tutorial

JAVA Tutorial

Kids Tutorial

Friday, 27 January 2017

Java Tutorial: Java Runtime class (How to terminate JVM using exit method)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=vBFQ0N_CFsA&list=UUhwKlOVR041tngjerWxVccw

Click the below Image to Enlarge

Java Tutorial: Java Runtime class (How to terminate JVM using exit method)

RuntimeDemo.java

import java.io.IOException;

/*
 * public void exit(int status)
 * 
 * Parameters: 
 * -----------
 * 
 * status - Termination status. By convention, a nonzero
 * status code indicates abnormal termination.
 */
public class RuntimeDemo
{

    public static void main(String[] args) throws IOException
    {
        /*
         * Returns the runtime object associated with the
         * current Java application.
         */
        Runtime runtime = Runtime.getRuntime();

        System.out.println("Before exit method is called..");
        /*
         * Terminates the currently running Java virtual
         * machine by initiating its shutdown sequence..
         */
        runtime.exit(0);

        System.out.println("After exit method is called..");
    }

}