Full stack tech reference blogs by Tirumal Sutrave

Create Database    create database <Database Name>; Selecting a Database   Use <Database Name>; List all tables in Database   show tables; Create User table CREATE TABLE USER ( ID int NOT NULL, NAME varchar(100) NOT NULL, EMAIL_ADDRESS varchar(100), PRIMARY KEY (ID) ) Or  CREATE TABLE USER ( ID int NOT NULL AUTO_INCREMENT, NAME varchar(100) NOT NULL, EMAIL_ADDRESS varchar(100) NOT NULL, SALARY double DEFAULT NULL, NOTE text, PRIMARY KEY (ID) )

Assumption :      You have MariaDB and Client installed. Steps:      Run client and create database using command "create database".       create database test;      Now, connect to that database using "USE" command       Use test;      Create new table USER with following command       CREATE TABLE USER (       ID int NOT NULL,       NAME varchar(100) NOT NULL,       EMAIL_ADDRESS varchar(100),       PRIMARY KEY (ID)       )      Now, download the driver from mysql site. I'm using "mysql-connector-java-5.1.46". MySql and MariaDB are similar so for basic connectivity mysql drivers works. Class.forName("com.mysql.jdbc.Driver"); java.sql.Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "password"); Prepare...

Polymorphism is word made from two words "Poly" which means many and "morph" means shape/form. Polymorphism means "ability to take multiple shapes or forms". In Java, method and Object both takes multiple forms. There are two forms of polymorphism : Compile time Polymorphism Run time Polymorphism Compile time polymerphism Compile time polymorphism is achieved using method overloading. Method will have same signaturre(name) but different parameters.This method is bound statically with method name and input parameter type hence static binding. Output : Display String Display int Runtime Polymorphism Method overriding is used to achieve Runtime polymorphism. Method will be overridden in subclass. This method is resolved depending on Object instance dynamically at runtime. Output : Display of Display Unit. Display of Monitor.

Inter thread communication is very interesting topic where you learn how two thread can talk to each other in a multi-threaded environment. And this is demonstrated with a very simple example of Producer-Consumer problem. Object class's wait and notify method will be used for inter thread communication. I'm assuming two thread Producer Consumer These will be spawned using main thread. Producer will try producing Product. Produce action will be represented by making Available property in Product Object true.  And consumer will be consuming that object by making available property false.  Same object will be used to pass to both threads for inter thread communication Code accessing same object will be synchronised  Main methods used are : Thread.sleep >> It will be used to give some delay so that we can understand code execution. Object.wait >> Wait will be called on product which will make current thread to release lock and wait. Object...

You might have seen mixed-content error while page rendered with HTTPS is making HTTP request. Your server is configured to SSL or to serve only HTTPS request. Server will block HTTP request mostly in this case unless configured so.  Active Mixed Content : It has access to all DOM in current HTML page. I can manipulate page. It can cause man-in-the-middle attack. JavaScript source, CSS source, link, XMLHttpRequest can cause such content. Passive Mixed Content : It is content which does not alter other parts of HTML page.Static image, audio, video link are cause of passive mixed content. You can quickly fix such errors by addressing following points : Use relative URL if content/resource hosted on same server If you are calling content from servlet/JSP/REST API, use relative URL load resources. If absolute URL is used, then make sure all entries for resource URL has HTTPS. make sure you are creating URL starting HTTPS If cross domain is used then use site whi...

Creating your own Weblogic local domain on Windows If you want create your own weblogic domain you have reached correct destination. You can use this domain for configuring server in Netbeans IDE. This installation is on OS Windows 7. Let's jump to configuring domain. 1. Go to Weblogic configurator and select Quick Launch 2. You will see quick launch screen one like below. Now click on "Getting Started with Weblogic 10.3.6". 3. Now you will see Configuration Wizard screen as below. Select "Create new Weblogic Domain". And click on Next. 4. You can select domain source as below. Configurator wizard will list all the domains. 5. Enter name and location in next screen. 6.Add username and password. Keep password alphanumeric one, should be combination of Letters and numbers like "Welcome1". This is important for logging in to admin console. 7. This is very important step. If you are using this in some IDE then select develop...

Please read about HelpProvider documentation from ADF Docs. Now you can go and implement your default help provider in ADF App. Whenever there is requirement to override default behavior of the help topic text and basically want to override behavior to accept any random help text from ELExpressions. Here we need to override some classes and make few configuration entries in adf-settings.xml file. 1. Extend HelpTopic class and override methods. Code should look something like  below.   1 package com.custom;   2    3 import javax.faces.component.UIComponent;   4 import javax.faces.context.FacesContext;   5    6    7 import com.custom.HelpTopic;   8    9 /**  10  * EPM help provider for help topic ids.  11  */  12 public class DefaultELHelpProvider extends HelpProvider {  13     /**  14      * Default constructor.  ...