Today's Question:  What does your personal desk look like?        GIVE A SHOUT

SEARCH KEYWORD -- NULL

  Removing duplicates in sql

In modern web development, it’s standard practice to make use of a database abstraction layer, typically an Object-Relational Mapper based on either the Active Record pattern or the Data Mapper pattern. There are several pros and cons to this which are fairly well established, so I’ll spare us all from enumerating them all right now. One established pro worth mentioning is that these systems typically provide a high level interface for fetching data, often removing the need to ...

   SQL,Duplicate,Remove,Web design     2012-01-05 08:20:13

  Generate certificate in Java -- Store certificate in KeyStore

In previous post, we have explained how to create a certificate chain in Java. After generating the chain, we need to store it somewhere so that it can be used later when we are doing the actual SSL communication, either in a key store or trust store. This post will show you how to store the private key and its associated certificate chain in a keystore file. There are different types of keystore in Java, in this post, we will choose the JKS to demonstrate how to store the certificate chain. Whe...

   Java,Certificate chain,Keystore     2014-08-20 03:56:39

  Some frequently used ES6 code snippets

Below are a list of ES6 code snippets which are used frequently. Hope that it will be helpful. 1. Shuffle array elements let arr = [67, true, false, '55'] arr = arr.sort(() => 0.5 - Math.random()) console.log(arr) // [ '55', 67, false, true ] 2. Remove characters which are not numbers const str = 'xieyezi 23213 is 95994 so hansome 223333' const numbers = str.replace(/\D/g, '') console.log(numbers) // 2321395994223333 3. Reverse sequence or words const sentence = 'xieyezi js so handsome, lol.'...

   JAVASCRIPT,ES6,CODE SNIPPET,TIPS     2022-04-10 07:56:07

  JavaScript to open link in new window without being popup blocked

To ensure security and reduce spamming, modern browsers have implemented very strict rules on when a new window can be opened in a web page. Currently browsers restrict that any new web page to be opened in a new window must be initiated with an user action. The action is usually an user click event. Otherwise, a popup blocker would show on the browser address bar which indicates that something is blocked. To workaround this issue, normally you should implement the window open logic in a click e...

   JAVASCRIPT,IFRAME,NEW WINDOW,OPEN LINK     2018-09-22 04:29:30

  Optional arguments in PHP function

In PHP, we can define our own functions which can accept optional number of arguments. In this kind of functions, the optional argument should be set with default value.Fox example, the next code example will illustrate this:<?php function func($name,$type=NULL) { echo "$name $type"; } func("Hello"); echo "<br />"; func("Hello","world"); echo "<br />";?>Here $type is an optional argument. It must be set with a default value either NULL or some other value. Quite simple....

   PHP,optional,arguments,user defined func     2011-03-28 12:35:20

  Basic Patterns for Everyday Programming

For most of you the patterns mentioned below should be nothing new. These are very basic stuff we slap into our code everyday and at times feels they are actually code smells than smart patterns. However, I've been doing some code reviewing lately and came across many code that lacks even these basic traits. So I thought of writing them down as a help for novice developers who would want to get a better grasp at these.These patterns are commonly applicable in most general purpose programming lan...

   Pattern,Code,NULL,Function,JavaScript,Assign default value     2011-11-23 08:03:55

  Different types of keystore in Java -- PKCS12

PKCS12 is an active file format for storing cryptography objects as a single file. It can be used to store secret key, private key and certificate.It is a standardized format published by RSA Laboratories which means it can be used not only in Java but also in other libraries in C, C++ or C# etc. This file format is frequently used to import and export entries from or to other keystore types. Next we will explain the operations which can be performed on PKCS12 keystore. Create PKCS12 keystore Be...

   Java, PKCS12, keystore, tutorial     2015-01-04 21:08:49

  Canonicalize XML in Java

XML canonicalization is often used when there is need to create digital signature to be sent to peers for verification. Since digital signature is created based on XML data, the XML data has to be canonicalized before its signature value can be calculated. Even an extra space may affect the signature value calculated, hence it must follow some rules to canonicalize the XML data so that it has a standard format. This is why W3C created specification Canonical XML Version 1.1. This specificat...

   JAVA,XML,JAVA SECURITY     2016-01-20 01:39:45

  Greedy and Nongreedy Matching in a Regular Expression

By default, pattern matching is greedy, which means that the matcher returns the longest match possible. For example, applying the pattern A.*c to AbcAbcA matches AbcAbc rather than the shorter Abc. To do nongreedy matching, a question mark must be added to the quantifier. For example, the pattern A.*?c will find the shortest match possible. COPY // Greedy quantifiers String match = find("A.*c", "AbcAbc"); // AbcAbc match = find("A.+", "AbcAbc"); // AbcAbc // Nongreedy quantifier...

   Regular expression,Pattern match,Greedy,     2011-08-09 12:42:28

  Turn on SecurityManager in Java

SecurityManager in Java is to check whether the application codes can access some restricted resource such as file, socket etc. This can be used in applications which have high security requirements. With this feature turned on, our system resources can be secured with only permitted operations. When JVM starts, it will first check whether the SecurityManager is on by checking the system property java.security.manager, if it's on, then an instance of SecurityManager will be created and it can be...

   SecurityManager,enable,program     2013-12-16 05:03:53

RECENT