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  Modal dialog in Java example code

In Java, we can create modal dialog so that the main JFrame cannot be operated on until the modal dialog is closed. To achieve this, we need to use one class in Java--JDialog. This class can be used to create an modal dialog.Example code : import javax.swing.JDialog; import javax.swing.JLabel; import javax.swing.JPanel; public class Dialog extends JDialog{ public Dialog(){ super(); JPanel panel=new JPanel(); panel.add(new JLabel("Hello dialog")); this.getCont...

   Java,Modal,JFrame,JDialog,Demo,Code     2011-08-18 09:50:27

  The several flavors of random in Java

Random number generation is one of most basic features in any programming language. The basic utilization is always the same: generate a random number between 0 and 1. With such a simple resource at hand we sometimes overlook some interesting features. What do we learn from the books? The most obvious and maybe intuitive way to generate random numbers in Java is simply calling: java.lang.Math.random() Random generation is in the Math utility class with abs, pow, floor...

   Java,Random,Thread,Math,Type     2012-03-22 14:17:44

  + operation on JavaScript objects

In JavaScript, there are two types of values: primitive and object. Primitives consist undefined, null, boolean, number and string. Other values such as array and function are objects. When applying + operation on different type of values, there would be three kinds of type conversion. Primitive conversion Number conversion String conversion There three type conversions have corresponding abstract operations in JavaScript: ToPrimitive(), ToNumber(), ToString(). For number additi...

   JAVASCRIPT,PROGRAMMING     2018-10-12 22:19:12

  A plugin to update last_error in Delayed Job

delayed_job is a process based asynchronous task processing gem which can be ran at background. It will fork the specified number of processes to execute the tasks asynchronously. The task status is usually stored in the database so that it can be easily integrated into a Rails application where asynchronous job execution is desired. Normally when a job fails to execute or error occurs, it would save the error into the database with the column last_error. Ideally all these will be handled b...

   RUBY,RUBY ON RAILS,DELAYED JOB,LAST_ERROR     2017-11-18 13:05:49

  A completely new approach to surveillance - should you be worried?

Paranoia is not necessarily a bad thing - assuming someone is really out there to get you. True or not, the paranoid have had issues they need to control explode as the internet developed, they also got specific tools to make their secrets (or their life, not everybody has a dark secret) more secure and under control. Unfortunately to them, and to the amazement of science and science fiction fans worldwide, a new way of obtaining secrets has appeared and it’s something very few expected. ...

   security     2014-08-11 05:41:58

  Use Java ThreadLocal with caution

According to Oracle documentation, ThreadLocal is a class provides thread-local variables. These variables differ from their normal counterparts in that each thread that accesses one (via its get or set method) has its own, independently initialized copy of the variable. ThreadLocal instances are typically private static fields in classes that wish to associate state with a thread. In short, ThreadLocal variables are variables belong to a thread, not a class or an instance of a class. One common...

   JAVA,MEMORY LEAK, THREADLOCAL     2015-11-03 07:31:57

  Singleton Pattern in Golang

Singleton pattern is the simplest design pattern in software design. It ensures that only one instance of an object exists globally, regardless of how many times the object is instantiated. Based on the characteristics of the singleton pattern, it can be applied to scenarios such as global unique configuration, database connection objects, file access objects, etc. In Go language, there are multiple ways to implement the singleton pattern. Today, let's learn together about some of these approach...

   GOLANG,SINGLETON PATTERN,TUTORIAL     2023-08-18 23:52:05

  Valid JavaScript variable names

Did you know var π = Math.PI; is syntactically valid JavaScript? I thought this was pretty cool, so I decided to look into which Unicode glyphs are allowed in JavaScript variable names, or identifiers as the ECMAScript specification calls them. Reserved words The ECMAScript 5.1 spec says: An Identifier is an IdentifierName that is not a ReservedWord. The spec describes four groups of reserved words: keywords, future reserved words, null literals and boolean lite...

   JavaScript,Name convention,Standard     2012-02-22 05:16:53

  How Integers Should Work (In Systems Programming Languages)

My last post outlined some of the possibilities for integer semantics in programming languages, and asked which option was correct. This post contains my answers. Just to be clear: I want practical solutions, but I’m not very interested by historical issues or backwards compatibility with any existing language, and particularly not with C and C++. We’ll start with: Premise 1: Operations on default integer types return the mathematically correct result or else trap. This is th...

   Number,Algorithm,System,Embedded system     2011-12-05 12:48:41

  The most stupid C bug ever

I have been programming for a number of years already. I have seen others introduce bugs, and I have also introduced (and solved!) many bugs while coding. Off-by-one, buffer-overflow, treating pointers as pointees, different behaviors or the same function (this is specially true for cross-platform applications), race conditions, deadlocks, threading issues. I think I have seen quite a few of the typical issues. Yet recently I lost a lot of time to what I would call the most stupid C bug in my ca...

   C,Bug,Stupid,Bug code,All     2011-08-26 02:37:29

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