Sử dụng "Window" Look and Feel

Sử dụng window look and feel trong swing. 
// Get the currently installed look and feel
LookAndFeel lf = UIManager.getLookAndFeel();

// Install a different look and feel; specifically, the Windows look and feel
try {
} catch (InstantiationException e) {
} catch (ClassNotFoundException e) {
} catch (UnsupportedLookAndFeelException e) {
} catch (IllegalAccessException e) {



Simple Regex syntax for validation!

In software development the Regex is popuplar and the easiest way in validation writing. But It's difficult to remember regex syntax, so this is a some rules to remember it.
  • The best way to remember regex syntax is by remembering three things Bracket, caret and Dollars.
    • Bracket:
      • "[" Square brackets: specify the character which needs to be matched.
      • "{" Curly brackets: specify how many character.
      • "(" Round brackets: grouping.
    • Caret: "^" start a regular expression
    • Dollars: "$" end of a regular expression
                Example:   ^[a-z](1,2)$
      • The above regex pattern will only take characters which lies between ‘a’ to ‘z’. The same is marked with square bracket to define the range.
      • The round bracket indicates the minimum and maximum length.
      • Finally caret sign at the start of regex pattern and dollar at the end of regex pattern specifies the start and end of the pattern to make the validation more rigid.
  • Enter characters between [a-g] with length of 3?
    • [a-g]{3}
  • Enter characters between [a-g] with maximum 3 characters and minimum 1 character?
    • [a-g]{1,3}
  • How can I validate data with 8 digit fix numeric format like 91230456, 01237648 etc?
    • ^[0-9]{8}$
  • A string with first 3 characters alphabets case insensitive and remaining 8 length numeric?
    • ^[a-zA-Z]{3}[0-9]{7}$
  • Can we see a simple validation for website URL’s?
    • ^www[.][a-z]{1,15}[.](com|net|org)$
  • The same for email validation
    • ^[a-zA-Z0-9]{1,10}@[a-zA-Z]{1,10}.(com|net|org)$


Tự xóa bỏ các import không sử dụng trong eclipse!

Khi các class được import nhưng không được sử dụng, thì chúng ta sẽ thấy các cảnh báo của eclipse. Chúng ta có thể xóa bỏ chúng một cách dễ dàng với một vài tùy chỉnh trong eclipse.

    1. Window-->References
        -->Selecte node: Java-->Editor-->Save Actions.

    2. Click on button Configure...
        Select Unnecessary Code tab --> check Remove unused imports

Good luck!