Java – Convert IP address to Decimal Number
In this tutorial, we show you how to convert an IP address to its decimal equivalent in Java, and vice versa. For examples : 255.255.255.255 <-> 4294967295 192.168.1.2 <-> 3232235778 1. IP Address to Decimal We show you two ways to convert an IP address to a decimal number Normal… Continue Reading
bit shifting bitwise ip address java
Java and “& 0xFF” example
Before you understand what is & 0xFF, make sure you know following stuffs : Bitwise AND operator, link. Converts hex to/from binary, and decimal to/from binary. In short, & 0xFF is used to make sure you always get the last 8 bits. Let’s see an example to convert an IP… Continue Reading
bit shifting bitwise ip address java
Spring MVC – How to include JS or CSS files in a JSP page
In this tutorial, we will show you how to include JavaScript and CSS files in a JSP page, with the Spring MVC framework environment. 1. Project Directory Review the final project directory structure. A standard Maven folder structure, put the JS and CSS files under the webapp\resources folder. 2. Resource… Continue Reading
css js spring mvc
Eclipse – java.lang.OutOfMemoryError: Java heap space
In Eclipse IDE, if your program is consuming a lot of memory (loads huge records) like this : List<Domain> list = domainBo.findAllDomain(100000); for(Domain domain : list){ process(domain.getDomainName()); } It can easily hit java.lang.OutOfMemoryError : Exception in thread "main" java.lang.OutOfMemoryError: Java heap space at java.util.HashMap.<init>(HashMap.java:209) at java.util.LinkedHashMap.<init>(LinkedHashMap.java:181) 1. Solution –… Continue Reading
eclipse memory
MongoDB – find all documents where an array / list size is greater than N
Review following documents : Collection : domain { "_id" : 1001, "domainName" : "google.com" "tag" : [ "search engine", "search", "find anything", "giant" ] }, { "_id" : 1002, "domainName" : "yahoo.com" "tag" : [ "search engine", "online portal", ] }, { "_id" : 1003, "domainName" : "mkyong.com" } 1.… Continue Reading
mongodb query
Spring MVC + jQuery Autocomplete example
In this tutorial, we show you how to integrate jQuery autocomplete plugin with Spring MVC. Tools and Libraries used : Spring MVC 3.2 jQuery autocomplete plugin – github Maven 3 Eclipse IDE Review the tutorial’s flows : An HTML page, with a textbox. If the user is tying on the… Continue Reading
autocomplete jquery spring mvc
Java Date and Calendar examples
This tutorial shows you how to work with java.util.Date and java.util.Calendar. 1. Java Date Examples Few examples to work with Date APIs. Example 1.1 – Convert Date to String. SimpleDateFormat sdf = new SimpleDateFormat("dd/M/yyyy"); String date = sdf.format(new Date()); System.out.println(date); //15/10/2013 Example 1.2 – Convert String to Date. SimpleDateFormat sdf… Continue Reading
calendar date Eclipse – How to attach JDK source code
This article shows you how to attach the JDK source code in Eclipse IDE. In Eclipse, select Windows -> Preferences -> Java -> Installed JREs , expands rt.jar, select “Source attachment” and find the src.zip from your disk drive. P.S JDK source code is inside the src.zip. Note You may… Continue Reading
eclipse source code
Where to download Java JDK source code ?
The JDK source code is inside the src.zip, this article shows you how to get it on Windows, Ubuntu (Linux) and Mac OSX. 1. Windows In Windows, visit the Oracle website and download the JDK (not JRE). Install the JDK and the src.zip is inside the JDK installed folder, for… Continue Reading
jdk source code Java – How to calculate leap year
A leap year is a year containing one additional day (366 days a year). Review the leap year algorithm : if year is divisible by 400 then is_leap_year else if year is divisible by 100 then not_leap_year else if year is divisible by 4 then is_leap_year else not_leap_year P.S Algorithm… Continue Reading
leap year Java – Time elapsed in days, hours, minutes, seconds
Two Java examples show you how to print the elapsed time in days, hours, minutes and seconds format. 1. Standard JDK Date APIs You need to calculate the elapsed time manually. DateTimeUtils.java package com.mkyong.dateUtils; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Date; public class DateTimeUtils { public static void… Continue Reading
date joda-time Spring Data MongoDB : get last modified records (date sorting)
In Mongodb, you can use sort()to do the date sorting. 1. MongoDB Sorting Examples In Mongodb, to sort a “date” field, issues : //The ’1′ = sort ascending (oldest to newest) db.domain.find().sort({lastModifiedDate:1}) { "_id" : 1, "lastModifiedDate" : ISODate("2013-08-13T07:18:04.774Z") } { "_id" : 2, "lastModifiedDate" : ISODate("2013-09-03T08:12:16.309Z") } {… Continue Reading
mongodb sorting spring-data Spring Data MongoDB : like query example
In SQL, the ‘like’ query is looks like this : select * from tags where tagName like ‘%apple%’ In MongoDB console, it looks like this : db.tags.find({"tagName": /apple/}) In Spring data mongodb, it implements with Criteria or BasicQuery : String tagName = "apple"; Query query = new Query(); query.limit(10);… Continue Reading
like query spring-data
jQuery loop over JSON string – $.each example
Review a simple jQuery example to loop over a JavaScript array object. var json = [ {"id":"1","tagName":"apple"}, {"id":"2","tagName":"orange"}, {"id":"3","tagName":"banana"}, {"id":"4","tagName":"watermelon"}, {"id":"5","tagName":"pineapple"} ]; $.each(json, function(idx, obj) { alert(obj.tagName); }); Above code snippet is working fine, prompts the “apple”, “orange” … as expected. Problem : JSON string Review below example, declares… Continue Reading
jquery json jQuery and Java List example
There is no direct way to iterate over a Java List with jQuery, see the following case study : Spring controller @RequestMapping(value = "/", method = RequestMethod.GET) public ModelAndView getPages() { List<String> list = new ArrayList<String>(); list.add("List A"); list.add("List B"); list.add("List C"); list.add("List D"); list.add("List E"); ModelAndView model… Continue Reading
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