SEARCH KEYWORD -- NULL


  10 design flaws of JavaScript

JavaScript's design took only ten days. Moreover, the designer didn't want to design it initially, he just wanted to complete the task assigned by company. It is now a very powerful client side programming language used in almost all the websites. It's an excellent language, but it also has some flaws. 1. Not suitable for large projects JavaScript doesn't have namespace, it's hard to be modular, there is no standard for putting codes in multiple source files. It allows defining functions with th...

   JavaScript, Design flaw, Object     2012-11-29 11:39:35

  Different types of keystore in Java -- PKCS11

PKCS11 keystore is designed for hardware storage modules（HSM）. It's an interface to talk to the HSMs. It doesn't actually store any keys but provide a set of classes to communicate with the underlying HSM. The actual keys and certificates are stored on the HSMs. The reason for storing the keys and materials is to ensure security and efficiency. Since the keys are on the HSMs, they are safe to be stolen. All encryption/decryption operations are performed on the HSMs as well, this incre...

   PKCS11,keystore,HSM,Java     2015-01-08 00:39:12

  PHP to get access token for Twitter app

Previously we wrote an article about getting access token for Facebook app--PHP to get access token for Facebook app. Today we will introduce how to get access token for Twitter app using PHP. Since now Twitter is also using OAuth 2.0 to allow some web apps to access some users information on behalf of one user. They provided some APIs for developers to easily get them integrated with their own websites. The first step to get all these done is how to get the access token, the access token seems ...

   Twitter,OAuth,access token,PHP     2013-03-03 03:49:26

  Why using + to concatenate string in Java loop is not a good option

String concatenation is a common operation in Java programming. It is to concatenate multiple strings into a single string. Java provides a String class which is an immutable class which means the object cannot be mutated once instantiated. Once a String object is instantiated, its properties cannot be changed anymore, so when concatenating strings, it's actually create a new String instance to store the concatenated string values. For example, below is a simple string concatenation example. Str...

   JAVA,STRING,JAVA 8     2019-01-18 22:07:12

  Crash your Chrome with %%30%30

Have you ever wondered a simple string can crash one of the most sophisticated designed web browsers -- Chrome? There is a finding from Andris Atteka who found that a null string "%%30%30" appended to an URL can crash Chrome. For example, if you have below URL in your browser address bar or you mouse over below URL, Chrome will crash: http://www.pixelstech.net/%%30%30 When the browser crashed, it may show : Or on Windows, you will see : This bug has been reported to Google at Is...

   CRASH,SECURITY,CHROME,GOOGLE     2015-09-20 08:24:16

  Chrome extension to display desktop notification

Have you ever thought about writing extension for web browsers so that we can complete some tasks easily. Do you think writing extension for browsers is very difficult? You have no clue where to begin? On Chrome, this isn't any problem now as long as you know how to write HTML,CSS and JavaScript. We will show one example of Chrome extension today. The extension will display a desktop notification on your desktop. You need to create two files here, one is the notification.json which is the config...

   Chrome extension,Desktop notification,Example     2013-06-29 22:23:51

  PHP 7 is coming soon

After a few RCs, PHP 7 will be officially released on November 12, 2015. This is a major release of PHP since PHP 5.6. @Laruence, one of the core contributors of PHP, has posted this news on Weibo(China's Twitter).  This is a one month later than the expected time as recorded in PHP 7 timeline. But it's not that late. The new release will come with a few features including: Scalar type declaration, you can define variable like int now Return type support. Besides declare scalar type ...

   RELEASE DATE,PHP7     2015-11-08 09:13:37

  The Evolution of a Programmer

High School/Jr.High 10 PRINT "HELLO WORLD" 20 END First year in College program Hello(input, output) begin writeln('Hello World') end. Senior year in College (defun hello (print (cons 'Hello (list 'World)))) New professional #include <stdio.h> void main(void) { char *message[] = {"Hello ", "World"}; int i; for(i = 0; i < 2; ++i) printf("%s", message[i]); printf("\n"); } Seasoned professional #include <iostream....

   Humour,Evolution,Programmer     2012-04-23 06:30:33

  Use DTrace to diagnose gdb issues

A few days ago, I installed the newest 64-bit gdb program (version 7.7.1) on Solaris 10 (X86_64 platform) to debug programs. After playing with the gdb a day, I found 2 issues about gdb:(1) The "set follow-fork-mode child" command doesn't take effect. By default, after the parent process forks the child process, the gdb will track the parent process, so this command can make gdb begin to follow the child process. But this command works OK on Linux.(2) The gdb can't parse the 32-bit application c...

   DTrace, debug, gdb, UNIX     2014-06-28 05:11:20

  When will resizing be triggered in Java HashMap?

HashMap is one of the most frequently used collection types in Java, it stores key-value pairs. Ideally it expects to use hash table which expects the data access time complexity to be O(1), however, due to hash conflicts, in reality, it uses linked list or red-black tree to store data which makes the worst case time complexity to be O(logn).  Although collections are using data structures like arrays and linked lists, unlike arrays, they will dynamically resize when there is not enough spa...

   JAVA,RESIZE,HASHMAP,THRESHOLD     2020-05-02 20:41:19

RECENT