Tutorial by Examples: o

String getText(String url) throws IOException { HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection(); //add headers to the connection, or check the status if desired.. // handle error response code it occurs int responseCode = conn.getResponseCod...

The Standard Edition of Java comes with some annotations predefined. You do not need to define them by yourself and you can use them immediately. They allow the compiler to enable some fundamental checking of methods, classes and code. @Override This annotation applies to a method and says that th...

Sometimes the same functionality has to be written for different kinds of inputs. At that time, one can use the same method name with a different set of parameters. Each different set of parameters is known as a method signature. As seen per the example, a single method can have multiple signatures....

Needed imports: import javax.sound.sampled.AudioSystem; import javax.sound.sampled.Clip; This code will create a clip and play it continuously once started: Clip clip = AudioSystem.getClip(); clip.open(AudioSystem.getAudioInputStream(new URL(filename))); clip.start(); clip.loop(Clip.LOOP_CO...

Paginations in JavaFX use a callback to get the pages used in the animation. Pagination p = new Pagination(); p.setPageFactory(param -> new Button(param.toString())); This creates an infinite list of buttons numbed 0.. since the zero arg constructor creates an infinite pagination. setPageFac...

Pagination p = new Pagination(10); Timeline fiveSecondsWonder = new Timeline(new KeyFrame(Duration.seconds(5), event -> { int pos = (p.getCurrentPageIndex()+1) % p.getPageCount(); p.setCurrentPageIndex(pos); })); fiveSecondsWonder.setCycleCount(Timeline.INDEFINITE); fiveSecondsWon...

ArrayList<String> images = new ArrayList<>(); images.add("some\\cool\\image"); images.add("some\\other\\cool\\image"); images.add("some\\cooler\\image"); Pagination p = new Pagination(3); p.setPageFactory(n -> new ImageView(images.get(n))); Note...

wait() and notify() work in tandem – when one thread calls wait() on an object, that thread will block until another thread calls notify() or notifyAll() on that same object. (See Also: wait()/notify() ) package com.example.examples.object; import java.util.concurrent.atomic.AtomicBoolean; p...

The Collections class offers two standard static methods to sort a list: sort(List<T> list) applicable to lists where T extends Comparable<? super T>, and sort(List<T> list, Comparator<? super T> c) applicable to lists of any type. Applying the former requires amending...

In your build.gradle file of main module(app), define your minimum and target version number. android { //the version of sdk source used to compile your project compileSdkVersion 23 defaultConfig { //the minimum sdk version required by device to run your app minSd...

Colors are usually stored in a resource file named colors.xml in the /res/values/ folder. They are defined by <color> elements: <?xml version="1.0" encoding="utf-8"?> <resources> <color name="colorPrimary">#3F51B5</color> <c...

A simple example of producer-consumer problem solution. Notice that JDK classes (AtomicBoolean and BlockingQueue) are used for synchronization, which reduces the chance of creating an invalid solution. Consult Javadoc for various types of BlockingQueue; choosing different implementation may drastica...

Java's Reflection API allows the programmer to perform various checks and operations on class fields, methods and annotations during runtime. However, in order for an annotation to be at all visible at runtime, the RetentionPolicy must be changed to RUNTIME, as demonstrated in the example below: @i...

First of all for a JAX-RS application must be set a base URI from which all the resources will be available. For that purpose the javax.ws.rs.core.Application class must be extended and annotated with the javax.ws.rs.ApplicationPath annotation. The annotation accepts a string argument which defines...

Date date = new Date(); System.out.println(date); // Thu Feb 25 05:03:59 IST 2016 Here this Date object contains the current date and time when this object was created. Calendar calendar = Calendar.getInstance(); calendar.set(90, Calendar.DECEMBER, 11); Date myBirthDate = calendar.getTime(); ...

Calendar, Date, and LocalDate Java SE 8 before, after, compareTo and equals methods //Use of Calendar and Date objects final Date today = new Date(); final Calendar calendar = Calendar.getInstance(); calendar.set(1990, Calendar.NOVEMBER, 1, 0, 0, 0); Date birthdate = calendar.getTime(); ...

format() from SimpleDateFormat class helps to convert a Date object into certain format String object by using the supplied pattern string. Date today = new Date(); SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MMM-yy"); //pattern is specified here System.out.println(date...

parse() from SimpleDateFormat class helps to convert a String pattern into a Date object. DateFormat dateFormat = DateFormat.getDateInstance(DateFormat.SHORT, Locale.US); String dateStr = "02/25/2016"; // input String Date date = dateFormat.parse(dateStr); System.out.println(date.getYe...

Calendar objects can be created by using getInstance() or by using the constructor GregorianCalendar. It's important to notice that months in Calendar are zero based, which means that JANUARY is represented by an int value 0. In order to provide a better code, always use Calendar constants, such as...

When desired XML format differs from Java object model, an XmlAdapter implementation can be used to transform model object into xml-format object and vice versa. This example demonstrates how to put a field's value into an attribute of an element with field's name. public class XmlAdapterExample { ...