Tutorial by Examples: re

ExecutorService ExecutorService executor = Executors.newFixedThreadPool(50); It is simple and easy to use. It hides low level details of ThreadPoolExecutor. I prefer this one when number of Callable/Runnable tasks are small in number and piling of tasks in unbounded queue does not increase m...

Entity class @Entity @Table(name = "USER") public class User { @Id @Column(name = "ID") private Long id; @Column(name = "USERNAME") private String username; @ManyToOne @JoinColumn("ORGANIZATION_ID") pr...

We can also specify that a virtual function is pure virtual (abstract), by appending = 0 to the declaration. Classes with one or more pure virtual functions are considered to be abstract, and cannot be instantiated; only derived classes which define, or inherit definitions for, all pure virtual fun...

#include <pthread.h> #include <stdio.h> #include <string.h> /* function to be run as a thread always must have the same signature: it has one void* parameter and returns void */ void *threadfunction(void *arg) { printf("Hello, World!\n"); /*printf() is speci...

Consider these two micro-benchmarks: The first benchmark simply creates, starts and joins threads. The thread's Runnable does no work. public class ThreadTest { public static void main(String[] args) throws Exception { while (true) { long start = System.nanoTime(); ...

Starting with a binary image, bwImg, which contains a number of connected objects. >> bwImg = imread('blobs.png'); >> figure, imshow(bwImg), title('Binary Image') To measure properties (e.g., area, centroid, etc) of every object in the image, use regionprops: >> stats = reg...

Conditions can also be expressions: $myInput = 0 switch($myInput) { # because the result of the expression, 4, # does not equal our input this block should not be run. (2+2) { 'True. 2 +2 = 4' } # because the result of the expression, 0, # does equal our input this ...

By default, Import-CSV imports all values as strings, so to get DateTime- and integer-objects, we need to cast or parse them. Using Foreach-Object: > $listOfRows = Import-Csv .\example.csv > $listOfRows | ForEach-Object { #Cast properties $_.DateTime = [datetime]$_.DateTime $...

The simple and most obvious way to use recursion to get the Nth term of the Fibonnaci sequence is this int get_term_fib(int n) { if (n == 0) return 0; if (n == 1) return 1; return get_term_fib(n - 1) + get_term_fib(n - 2); } However, this algorithm does not scale for higher ...

Executors returns different type of ThreadPools catering to specific need. public static ExecutorService newSingleThreadExecutor() Creates an Executor that uses a single worker thread operating off an unbounded queue There is a difference between newFixedThreadPool(1) and newSingleThreadE...

C# 7.0 allows throwing as an expression in certain places: class Person { public string Name { get; } public Person(string name) => Name = name ?? throw new ArgumentNullException(nameof(name)); public string GetFirstName() { var parts = Name.Split(' '); ...

C# 7.0 adds accessors, constructors and finalizers to the list of things that can have expression bodies: class Person { private static ConcurrentDictionary<int, string> names = new ConcurrentDictionary<int, string>(); private int id = GetId(); public Person(string n...

There are three ways you can access the Unity Asset Store: Open the Asset Store window by selecting Window→Asset Store from the main menu within Unity. Use the Shortcut key (Ctrl+9 on Windows / ⌘9 on Mac OS) Browse the web interface: https://www.assetstore.unity3d.com/ You may be prompted to...

NOTE: For brevity, the examples below use the FolderExists function from the Determining If Folders and Files Exist example in this topic. The MkDir statement can be used to create a new folder. It accepts paths containing drive letters (C:\Foo), UNC names (\\Server\Foo), relative paths (..\Foo...

Internally, all videos are a just series of pictures. Let's take a look at one such picture. That looks odd, right? Indeed. The pictures that make up a video may have an aspect ratio that are different from the DAR, most often for algorithmic reasons (e.g. only sizes that are a multiple of 16 can...

Consider the following list comprehension Python 2.x2.7 i = 0 a = [i for i in range(3)] print(i) # Outputs 2 This occurs only in Python 2 due to the fact that the list comprehension “leaks” the loop control variable into the surrounding scope (source). This behavior can lead to hard-to-find...

To create a Behavior just extend the CoordinatorLayout.Behavior class. Extend the CoordinatorLayout.Behavior Example: public class MyBehavior<V extends View> extends CoordinatorLayout.Behavior<V> { /** * Default constructor. */ public MyBehavior() { ...

You can use the CoordinatorLayout.Behavior to create dependencies between views. You can anchor a View to another View by: using the layout_anchor attribute. creating a custom Behavior and implementing the layoutDependsOn method returning true. For example, in order to create a Behavior for m...

Using a list object you can create a fully functional generic Stack with helper methods such as peeking and checking if the stack is Empty. Check out the official python docs for using list as Stack here. #define a stack class class Stack: def __init__(self): self.items = [] ...

Smack (Java) Using Smack 4.1 It is recommended to include Smack as Maven dependency in your project (e.g. by using gradle or Maven). Otherwhise the following Smack artifacts/jars have to be added manually to the classpath: smack-core, smack-extensions, smack-experimental, smack-im, smnack-tcp,...