When you start a new Spring roo project, the default page will be “index.jspx”, what if we want to implement a controller to it?

First of all, locate the webmvc-config.xml in your project folder. Find and remove the following line
<mvc:view-controller path="/index"/>

Then, create a Java class file in the source folder, in my case, will be the web folder. Let’s call it IndexController

package com.justthor.web;

import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@RequestMapping("/")
@Controller
public class IndexController {
  @RequestMapping(value = "/index", method = RequestMethod.GET)
  public String index(ModelMap modelMap) {
          /* Implement logic here...*/
          return "index";
  }
}

Happy coding

Here’s the code of it.

package com.justthor.reader

import scala.io.Source
import scala.xml._

object SimpleFeedReader {
  def main(args : Array[String]) : Unit = {
    val url = "http://just-thor.com/feed/"
    val data = XML.loadString( Source.fromURL(url).mkString )
    data \ "channel" \ "item" foreach(
      a => println((a \ "title" text) + " == "  + (a \ "link" text))
    )
  }
}

Ok,let’s go thru the code line by line.

At line 09, again we use Source to load content from url,by calling the method fromURL(quite obvious,right?).The mkString will create a String out of the content. Then, we use XML.loadString to parse the String into an XML object.

At line 10, we traverse the XML object with something like XQuery.
The RSS xml format is something like this

<channel>
<link>...</link>
<description>...</description>
<!-- item 1-->
<item>
  <title></title>
  <link></link>
</item>
<!-- item 2-->
<item>
  <title></title>
  <link></link>
</item>
<!-- and the rest goes here -->
</channel>

So when we write

data \ "channel" \ "item"

Here’s the output of the result

File Reading in Java and Scala == http://just-thor.com/2009/10/01/file-reading-in-java-and-scala/
PHP communicate with Java using JSON – Unicode Version == http://just-thor.com/2009/09/28/php-communicate-with-java-using-json-unicode-version/
Scala And JDBC == http://just-thor.com/2009/09/27/scala-and-jdbc/
A mistake or fate? == http://just-thor.com/2009/09/17/a-mistake-or-fate/
Women are weird == http://just-thor.com/2009/09/13/women-are-weird/
20 must visit sites for Java developer == http://just-thor.com/2009/09/12/20-must-visit-sites-for-java-developer/
Why do I practice pair programming? == http://just-thor.com/2009/09/08/why-do-i-practice-pair-programming/
Installing Scala on Windows == http://just-thor.com/2009/09/02/installing-scala-on-window/
Logging for different requested URI in Apache HTTP Server == http://just-thor.com/2009/09/01/logging-for-different-requested-uri-in-apache-http-server/
Say hello to Java and Scala == http://just-thor.com/2009/08/30/say-hello-to-java-and-scala/

And now we have a very simple yet functional RSS parser.

Happy coding,

For instance,we want to store a PHP array in database and later to be processed by Java,we can do something like

$aValue = array("key1"=>"value1","key2"=>"value2");
$sEncodedValue = json_encode($aValue)
//we will get something like {"key1":"value1","key2":"value2"}
//and then, we store the value to db

On the other hand,we use Java to read it and decode it.

//read from db and got the resultset,assuming we are using JDBC
while (rs.next()){
String rawValue = rs.getString("encodedValue");
// since we encoded an associative array,it will be translated to a Java Map object instance.
// we are using JSON-lib for JSON parsing the following example
JSONObject json = JSONObject.fromObject(jsonString);
Map decodedValue = (Map) JSONObject.toBean(json, Map.class);
String value1 = decodedValue.get("key1");
}

What if we are trying to store unicode value using JSON format in PHP?
For example,

$aValue = array("key1"=>"你好吗","key2"=>"value2");
$sEncodedValue = json_encode($aValue);
//This is what we get after encoded
//{"key1":"\u4f60\u597d\u5417","key2":"value2"}

If you decoded it back to Java,key1 value will return “u4f60u597du5417″ instead.This is so wrong.

How to solve it?
We can use mb_convert_encoding function in PHP.
Let’s make some changes to our code.

$aValue = array("key1"=>mb_convert_encoding("你好吗", "UTF-8"),"key2"=>"value2");
$sEncodedValue = json_encode($aValue);

By doing so,values are stored in database in unicode format,and you can decode it back in Java.

Happy coding.

1.http://www.javaalmanac.com

2.http://www.onjava.com

3.http://java.sun.com

4.http://www.developer.com/java

5.http://www.java.net

6.http://www.builder.com

7.http://www.ibm.com/developerworks/java

8.http://www.javaworld.com

9.http://www.devx.com/java

10.http://www.fawcette.com/javapro

11.http://www.sys-con.com/java

12.http://www.javadesktop.org

13.http://www.theserverside.com

14.http://www.jars.com

15.http://www.jguru.com

16.http://www.javaranch.com

17.http://www.ibiblio.org/javafaq/javafaq.html

18.http://java.sun.com/docs/books/tutorial/

19.http://www.javablogs.com

20.http://java.about.com/

Happy coding.

So I started off with myself, everyday I was pairing with one of them. The reason why I didn’t straightaway implementing it through out the team was because by then I wasn’t so sure about this practice would actually helps to increase the productivity and quality like what stated in any XP books.

At first, they were thinking that I am going to help them with their work. I was like,”Hell no I am not!I am not going to code or do your work for you. Instead, I am going to do your work with you. OK, let’s start by going through the design.”

Pairing up is great, I get to understand their design and discuss with them, and also it’s a good chance for me to spreading out knowledge like how to format the code, how do we normally name it etc. End of the sprint, we talked about the pairing process, and turned out everyone loves it. From that sprint onwards, we started practicing pair programming.

You might be curious, how come when 2 person using one workstation to develop will actually increase productivity? Isn’t that 2 people can do more work? Let’s elaborate the advantages one by one.

• Increase productivity – If you enjoy reading news, browsing forums, writing blogs, chatting with some chicks in front of your colleague, this rules probably doesn’t apply to you.
• Code quality – There is always another person sits beside you and look at what you have code. This actually reduce the chances someone accidentally injected buggy code into the system.
• Better design – You can always discuss with your partner about your design and get some ideas on how to improve it.
• Reduce your workload – There are always other people who knows the design and the code when you pairing up with them. Therefore, when you going off on a vacation, you won’t have to worry your office will call you up and telling you that the website is down.

So, shall you practice pair programming? It depends on the team culture. If the some members are trying to hide their skills or expect his partner to do all the work, then this might not be a suitable practice. In my opinion, agile development practices are always depends on human who practice it. It can only identify human problem, but never expect it will solve it for you.

Happy coding.

This is how we do in Java.

public class Hello {
 public static void main(String[] args) {
  System.out.println("Hello world");
 }
}

object Hello {
 def main(args : Array[String]) = println("Hello world")
}

Java style

public class HelloArgument {
 public static void main(String[] args) {
  for (String arg : args) {
   System.out.println("Hello, " + arg);
  }
 }
}

Scala style

object HelloArgument {
 def main(args : Array[String]) = args.foreach(arg => println("Hello, " + arg))
}

Pretty impressive,huh?Comparing Java,we are actually writing less and more readable code in Scala,and the results are the same.

Happy coding.

How do we do that in Javascript?

Lets say originally we have like 3 cookies value storing for the same domain.

document.cookie = "cookie1=val1;path=/;domain=just-thor.com"
document.cookie = "cookie2=val2;path=/;domain=just-thor.com"
document.cookie = "cookie3=val3;path=/;domain=just-thor.com"

document.cookie = "allcookies=cookie1=val1|cookie2=val2|cookie3=val3;path=/;domain=just-thor.com"

var cookieArray = translateCookiesToArray(new Array(), "allcookies");
// you can append more items into the array by calling
// cookieArray = translateCookiesToArray(cookieArray, "anotherCookiesCollection");

function translateCookiesToArray(result, key) {
 rawString = getCookieValue(key);
 if (rawString != null) {
 tokenizedString = rawString.split("|");

 for (i=0;i<tokenizedString.length;i++){
 innerArray = tokenizedString[i].split("=");
 result[innerArray[0]] = innerArray[1];
 }
 }

 return result;
}

cookieArray["cookie1"]

Here’s the complete code

var cookieArray = translateCookiesToArray(new Array(), "allcookies");

function translateCookiesToArray(result, key) {
 rawString = getRawCookieValue(key);
 if (rawString != null) {
  tokenizedString = rawString.split("|");

  for (i=0;i<tokenizedString.length;i++){
   innerArray = tokenizedString[i].split("=");
   result[innerArray[0]] = innerArray[1];
  }
 }

 return result;
}

function getRawCookieValue(name)
{
 var arg = name + "=";
 var alen = arg.length;
 var clen = document.cookie.length;
 var i = 0;
 while (i < clen) {
  var j = i + alen;
  if (document.cookie.substring(i, j) == arg) {
   return getCookieByOffset(j);
  }
  i = document.cookie.indexOf(" ", i) + 1;
  if (i == 0) break;
 }
 return null;
}

function getCookieByOffset (offset)
{
 var endstr = document.cookie.indexOf (";", offset);
 if (endstr == -1) {
  endstr = document.cookie.length;
 }
 return unescape(document.cookie.substring(offset, endstr));
}
function getCookieValue (name)
{
 value = cookieArray[name];
 if (typeof value == "undefined") {
  value = null;
 }
 return value;
}
//retrieving value
var val1 = getCookieValue("cookie1");

Happy coding