All static final class fields in java should be upper case with underscore between words.
2. Sun Microsystems PDF - Java Coding Style Guide
3.3 Field naming
Names of fields being used as constants should be all upper-case, with underscores separating words.
The following are considered to be constants:
- All static final primitive types (Remember that all interface fields are inherently static final).
- All static final object reference types that are never followed by "." (dot).
- All static final arrays that are never followed by "[" (dot).
Achut Reddy - Server Management Tools Group - Sun Microsystems
Links to this pdf:
3. JDK examples
// java.lang.Boolean public static final Boolean TRUE = new Boolean(true); public static final Boolean FALSE = new Boolean(false); // public static final Class<Boolean> TYPE = (Class<Boolean>) Class.getPrimitiveClass("boolean"); // java.lang.Math public static final double E = 2.7182818284590452354; public static final double PI = 3.14159265358979323846; // java.lang.Character public static final int MIN_RADIX = 2; public static final int MAX_RADIX = 36;