Code Conventions for the Java Programming Language

Two blank lines should always be used in the following circumstances:

• Between sections of a source file
• Between class and interface definitions

• Between methods
• Between the local variables in a method and its first statement
• Before a block (see section 5.1.1) or single-line (see section 5.1.2) comment
• Between logical sections inside a method to improve readability

• A keyword followed by a parenthesis should be separated by a space. Example:

  
         while (true) {
             ...
         }
  

  Note that a blank space should not be used between a method name and its opening parenthesis. This helps to distinguish keywords from method calls.

• A blank space should appear after commas in argument lists.
• All binary operators except . should be separated from their operands by spaces. Blank spaces should never separate unary operators such as unary minus, increment ("++"), and decrement ("--") from their operands. Example:

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

• The expressions in a for statement should be separated by blank spaces. Example:

  
      for (expr1; expr2; expr3)
  

• Casts should be followed by a blank space. Examples:

  
      myMethod((byte) aNum, (Object) x);
      myMethod((int) (cp + 5), ((int) (i + 3)) 
                                    + 1);