Forewords

This document describes a list of coding conventions that are required for code submissions to the project. By default, the coding conventions for most Open Source Projects should follow the existing coding conventions in the code that you are working on. For example, if the bracket is on the line after the if statement, then you should write all your code to have that convention.

Below is a list of coding conventions that are specific to this project. Anything else not specifically mentioned here should follow the official Sun Java Coding Conventions.

Project specific coding conventions

  1. Brackets

    All brackets (class, method, if, try, etc) must begin and end on a new line. Example :

    public class SomeClass
    {
        public void someMethod()
        {
            if (xxx)
            {
            }
        }
    }

    Brackets are mandatory, even for single line statements!

    // Incorrect
    if (expression)
        // some code
    
    // Correct
    if (expression)
    {
        // some code
    }
  2. Blank Spaces

    keywords followed by a parenthesis should be separated by a space. Example :

    while (true)
    {
        // some code
    }
    

    Blank space should appear after commas in argument lists. Binary operators should be separated from their operands by spaces :

    a += c + d;
    a = (a + b) / (c * d);
    
    while (d++ = s++)
    {
        n++;
    }
    
    printSize("size is " + foo + "\n");
  3. Indentations

    4 spaces. NO tabs . Period. We understand that a lot of you like to use tabs, but the fact of the matter is that in a distributed development environment, when the cvs commit messages get sent to a mailing list, they are almost impossible to read if you use tabs.

    1. Comments

      Javadoc SHOULD exist on all your class members (methods + class variables), including the private ones. Also, if you are working on existing code and there currently isn't a javadoc for that method/class/variable or whatever, then you should contribute and add it. This will improve the project as a whole.

      Also add code comments when you think it's necessary (like assumptions), especially when the code is not obvious.

  4. Author references

    If you contribute to a file (code or documentation), add yourself to the top of the file (below the existing authors). For java files the preferred Javadoc format is:

    @author devnickname
  5. Class variables

    Class variables should not have any prefix and must be referenced using the this object. Example :

    public class SomeClass
    {
        private String someString;
    [...]
        public void someMethod()
        {
            logger.debug("Value = " + this.someString);
        }
    }
  6. Parameter names

    Method parameters should not have any prefix. For example :

    public void someMethod(String className)
    {
    }
  7. Line length

    Avoid lines longer than 120 characters for Code, comments, ...

  8. Versioning

    All .java files should have a @version tag like the one below.

    @version $Id$
  9. Qualified imports

    All import statements should containing the full class name of classes to import and should not use the "*" notation :

    An example:

    // Correct
    import java.util.Date;
    import java.net.HttpURLConnection;
    
    // Not correct
    import java.util.*;
    import java.net.*;