How to clear textarea's default text

Often there may be requirements that a html form with a textarea containing a default text clears automatically when someone selects/clicks on the textarea.
This is achieved as below.

How to convert Byte[] array to String in Java

In some cases, we have to convert String variable into a Byte array format, for example, JCE encryption. However how do we convert a Byte[] array to String afterward?

Simple toString() function like following code is not working property. It will not display the original text but byte value.

String s = bytes.toString();

In order to convert Byte array into String format correctly, we have to explicitly create a String object and assign the Byte array to it.

public class TestByte
{ 
public static void main(String[] argv) {

    String example = "This is an example";
    byte[] bytes = example.getBytes();

    System.out.println("Text : " + example);
    System.out.println("Text [Byte Format] : " + bytes);
    System.out.println("Text [Byte Format] : " + bytes.toString());

    String s = new String(bytes);
    System.out.println("Text Decryted : " + s);
  }
}

How to change the port number of tomcat?

Now today lets learn how to change the tomcat port number? Whether it is Apache Tomcat 5 or Tomcat 6, by default Apache Tomcat runs on port 8080. But there can be situations where there are some other servers running on this same port forcing you to change the port of one of the servers.

This article explains how to change this port 8080 on Tomcat (tested this against Apache Tomcat 5.5 and 6.0 versions).

Here we’ll be using label to denote the folder where Tomcat is installed. In my system, tomcat is installed in the following path.

C:\Java\Tomcat_x.x

We need to edit the file named server.xml inside \conf folder.



In the server.xml file; locate the following segment.

By changing this 8080 value of port attribute, server would start listening on new port number.
After saving the changed server.xml file, Tomcat server must be restarted (stop then start) to activate the change. Hope you find it useful!

Time Picker using HTML and Java Script

Today while migrating the application, I was in need of having a textfield which takes time as an input. For this reason I needed a time picker, which will help the users to enter the time just by selecting something. I searched in web for this and found one from http://www.nogray.com/time_picker.php. This is very useful source for some most widely used javascripts like calendar, color picker, menubar etc.

Simple, basic but much needed things in java

It is often needed to convert one type of objects into another type in java. Below I have mentioned about these common types as they form basic foundation in java.

* How to convert String to boolean?

String listing = "true";
boolean theValue = Boolean.parseBoolean(listing);

* How to convert boolean to string?

public class BooleanToString {
public static void main(String[] args){
boolean b = true;
String s = new Boolean(b).toString();
System.out.println("String is:"+ s);
}
}

* How to converting string to date?

public class StringToDate {
public static void main(String[] args) {
try {
String str_date="11-June-07";
SimpleDateFormat formatter ;
Date date ;
formatter = new SimpleDateFormat("dd-MMM-yy");
date = (Date)formatter.parse(str_date);
System.out.println("Today is " +date );
}
catch (ParseException e)
{
System.out.println("Exception :"+e);
}
}
}

* How to convert date to string?

import java.util.*;
import java.text.*;
public class DateToString {
public static void main(String[] args) {
try {
DateFormat formatter ;
Date date ;
formatter = new SimpleDateFormat("dd-MMM-yy");
date = (Date)formatter.parse("11-June-07");
String s = formatter.format(date);
System.out.println("Today is " + s);
} catch (ParseException e)
{System.out.println("Exception :"+e); }

}
}