How to Install Java In Ubuntu

Which Version of Java to Use?

• JDK 7 supports:
• eclipse version 4.4 - 4.5
• JBoss AS 7 with Java EE 6 features
• Tomcat 7-8 with WebSockets
• JDK 8 (LTS) supports:
• eclipse from eclipse Neon (4.6) to eclipse 2020-06 (4.16)
• WildFly from 8 to 13 with Java EE 7 features
• WildFly from 14 to 25 with Jakarta EE 8 features
• Tomcat 9 with Java EE 8 features
• Eclipse GlassFish 5.1.0 with Java EE 8 and Jakarta EE 8
• Eclipse Glassfish 6.0.0 with Jakarta EE 9
• JDK 11 (LTS) supports:
• eclipse IDE from Eclipse 4.17 (2020-09) to Eclipse 4.24 (2022-06)
• Eclipse Glassfish 6.1 with Jakarta EE 9.1
• JDK 17 (LTS) supports:
• eclipse IDE from eclipse 4.25 (2022-09) to eclipse 4.28 (2023-06)
• Eclipse Glassfish 6.2.2 with Jakarta EE 9.1

By march 2019, Java SE 8 will go through the End of Public Updates process, because it is a legacy release.

The java programming language is an open source project. The OpenJDK community works for a free open-source implementation of the Java SE standard and Oracle contribute to the OpenJDK project. Beginning with Java SE 11 (September 2018, LTS), Oracle provide free releases and commercially supported releases for use with Oracle products: OpenJDK (free) and Oracle JDK (commercial) builds from Oracle. The OpenJDK project is the basis for both OpenJDK and Oracle JDK builds: applications will run interchangeably on Oracle JDK-11 and OpenJDK JDK-11.

jQuery and forms

Selecting form controls with jQuery selectors

jQuery selector working with forms are not always the fastest option to select elements: when you use them remember to reduce the number of elements jQuery needs to look through. Orthewise, use common CSS selectors

Example of use of jQuery selectors for forms

/* to start, select all form descendants,
   then, use the filter() method on the initial selection */
var $formDescs = $('form *');

/* :input selects all button, input, select and textarea */
var $inputs = $formDescs.filter(':input');
  
/* :text selects input type="text" and input */  
var $text = $inputs.filter(':text'); 

/* :password selects input type="password" */
var $password = $inputs.filter(':password');   

/* :button selects button and input type='button' */
var $button = $inputs.filter(":button");  

/* :checked selects all checked inputs from group of radio and check inputs */
var checked = $inputs.filter(":checked");

/* :selected selects all selected options from drop boxes */
var selected = $inputs.filter(":selected"); 

jQuery Effects

Effects

jQuery effects includes transitions and movements

• show and hide elements
• animate elements with fade in and fade out
• animate elements with slide up and slide down

	jQuery method	method meaning
Basic Effects	$('selector').show()	set the display CSS property to element's default value
	$('selector').hide()	set the display CSS property to none
	$('selector').toggle()	toggle between showing and hiding elements
Fading Effects	$('selector').fadeOut()	make element disappear by changing both opacity and display CSS properties
	$('selector').fadeIn()	make element appear by changing both opacity and display CSS properties
	$('selector').fadeTo()	change the opacity CSS property
	$('selector').fadeToggle()	hide or show the element
Sliding Effects	$('selector').slideUp()	hide the element with sliding movement
	$('selector').slideDown()	show the element with sliding movement
	$('selector').slideToggle()	hide or show the element
Custom Effects	$('selector').delay()	delay the execution of the following method
	$('selector').stop()	stop the animation
	$('selector').animate()	create a custom animation

jQuery Traversing and Filtering

DOM Traversing

The jQuery methods for traversing the DOM allow to access other element nodes relative to the initial selection.

jQuery method	method meaning
$('selector').find('selector2')	all the elements in the current selection matching selector2
$('selector').closest('selector2')	the nearest ancestral element matching selector2
$('selector').parent()	the direct parent element of current selection
$('selector').parents()	all the parents of current selection
$('selector').children()	all the children of current selection
$('selector').next()	next sibling of current element
$('selector').prev()	previous sibling of current element

jQuery and events

Checking When a Page is Ready For Your Code

The ready() method executes its function argument when the page is ready to work

$(document).ready(function(){
  // function body
});

• Behind the scenes, the ready() method add a listener for DOMContentLoaded events or for load events (in browsers that do not support HTML5 events a load event is fired instead)

There is a shorthand code for the ready() method:

$(function(){
  // function body
});

If you do not wish to use jQuery but still run your code when the page is ready to work, place your script before the body closing tag.

Scripting DOM and CSS with jQuery

Getting and Setting Element Content

The .html() and .text() methods retrive and update the content of elements.

How To Retrieve Element Content

jQuery method	method meaning
html = $('selector').html()	get the HTML content of the first element in the jQuery selection
text = $('selector').text()	get the textual content from every element in the jQuery selection and any descendant

Introduction to jQuery Library

What is jQuery

jQuery is a javascript library you include in your web pages.
jQuery allows you to select elements using a CSS-style selector and do something with those elements by calling a jQuery method.

Selecting HTML elements with jQuery

$('p');  /* a jQuery object */

• $() works as short invocation to the jQuery() function
• $() creates a jQuery object which stores references to the selected elements

CSS Selectors Level 3

Table of Contents

    1 Selector Syntax
    2 Simple Selectors
      2.1 Type selector (or Tag selector)
      2.2 Universal Selector
      2.3 Attribute selector
      2.4 Class (attribute) selector
      2.5 ID (attribute) selector
      2.6 Pseudo-classes
    3 Pseudo Elements
      3.1 The ::first-line pseudo-element
      3.2 The ::first-letter pseudo-element
      3.3 The ::before and ::after pseudo-elements
    4 Combinators
      4.1 Descendant combinator
      4.2 Child combinators
      4.3 Sibling combinators
    5 Calculating a selector's specificity

1. Selector Syntax

Selector

A selector is one or more sequences of simple selectors separated by combinators, an optional pseudo-element may follow the last sequence of simple selectors

selector = sequenceOfSimpleSelectors [combinator1 sequenceOfSimpleSelectors1 ... ] [::pseudoElement]

A sequence of simple selectors

• it is a chain of simple selectors that are not separated by a combinator
• it always begins with a type selector or a universal selector. No other type selector or universal selector is allowed in the sequence
• simple selectors are: type selector, universal selector, attribute selector, class selector, ID selector, pseudo-class.
• combinators are: whitespace, > "greater-than sign", + "plus sign", ~ "tilde"

The subjects of a selector are the elements of a document tree that are represented by the selector.

1.2 Group of Selectors

A comma-separated list of selectors represents all elements selected by each selector in the list. In CSS, if several selectors share the same declarations, they may be grouped into a comma-separated list.

Example: three CSS rules are condensed into one

h1 { font-family: sans-serif }
h2 { font-family: sans-serif }
h3 { font-family: sans-serif }
is equivalent to:

h1, h2, h3 { font-family: sans-serif }

Types of JavaScript Events

W3C DOM Events

DOM Level 2 UIEvent: user interface events occur for interactions with browser's window

type	event description	target
load	Fires when HTML and all resources of a web page have finished loading	document, window
unload	Fires when web page is unloading for a new page requested	body, window
error	Fires when browser encounter a JS error or resource does not exist (inconsistent support)
resize	Fires repeatedly as browser's window is being resized	window
scroll	Fires repeatedly as user scrolls web page	document, element
Usage: The load event is commonly used to trigger scripts that access the content of a page. It can cause the page to look slow, because it is raised only when all images are fully loaded. As resize and scroll events fire repeatedly, do not use them to trigger complicated code.

JavaScript Events

Types of Events

In a browser events are dispatched to objects to signal that something has happened, such as network activity or user interaction.

• W3C DOM Events Interfaces
• UIEvent: user interface events occur for an interaction with browser's window
• FocusEvent: occur when an element (link or form field) gains or loses focus
• MouseEvent: occur when user uses mouse, touchscreen, trackpad
• KeyboardEvent: occur when user uses keyboard
• [deprecated] MutationEvent: occur for a modification of DOM structure or DOM node
• MutationObserver: occur for a modification of DOM structure or DOM node
• W3C HTML5 Events Interfaces
• FormEvent: occur for an interaction with form element
• Various Interfaces: occur for an interaction with web page
• Vendor Specific BOM Events
• Events that deals with touchscreen and accelerometer

The DOM API

Browsers come with a set of built-in objects that model data used and operations performed by your applications:

• The Browser Object Model API (BOM) features Window object that models browser's windows and tabs.
• The Document Object Model API (DOM) features Document object that models web pages displayed in browser's windows.

The DOM API specification serves two purposes:

• how browser should make a model of HTML documents using objects:
  When a browser loads a web page, it creates a structure, a DOM tree, that is a live representation of the web page. The DOM tree is made of Node objects and each node represents an element that is part of the web page.
• how JS programs can access this model for changing HTML documents:
  JavaScript program can access the DOM tree for modifying the HTML document. This does not change the HTML code, but only the DOM, the representation of the document.