Here I would like to give some basic code conventions in Java that mostly we need in our daily programming life:
Indentation
Use 4 spaces for indentation. No tabs!
If you are using Eclipse, you can configure this at
- With Eclipse 3.7: Window->Preferences->Java->Code Style->Formatter
- Edit on one selected convention, example: Java Conventions [built-in] and go to tab: Indentation
Brackets
Easy to read, place open braces on the line after the declaration, for example:
public class Foo extends Bar { public static void main(String args[]) { try { for (int i = 0; i < args.length; i++) { System.out.println(Integer.parseInt(args[i])); } } catch(NumberFormatException e) { e.printStackTrace(); } } }
Another popular one: Java convention (Eclipse) ~ I still like this one:
/** * Description here * @author ABC * @version $Revision$ */ public class Foo extends Bar { public static void main(String args[]) { try { for (int i = 0; i < args.length; i++) { System.out.println(Integer.parseInt(args[i])); } } catch(NumberFormatException e) { e.printStackTrace(); } } }
Line Wrapping
Wrap lines longer than 100 characters. For wrapped lines, either use an indent of 8 characters or align with the expression at the same level on the previous line.
Declarations
Within a class or interface, definitions should be ordered as follows:
- Class (static) variables
- Instance variables
- Constructors
- Methods
Imports
Do not use package imports (for example: import java.util.*;), please use full import for each class (for example: import java.util.LinkedList;)
For Eclipse Users
You can use built-in some formatter such as: Java Conventions [built-in] (my recommendation) that already apply well enough to code:
Some important shortcut keys:
- Reformat your code by using Source->Format (Ctrl+Shift+F)
- Format your import statements appropriately when you invoke Source -> Organize Imports (Ctrl+Shift+O)