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Although recompiling Bar.java solves this problem, a better solution is available.

Compliant Solution

Wiki MarkupAccording to \[[ §13.4.9, "{{final}} Fields and Constants" ]\] of the Java Language Specification (JLS 2005),

Other than for true mathematical constants, we recommend that source code make very sparing use of class variables that are declared static and final. If the read-only nature of final is required, a better choice is to declare a private static variable and a suitable accessor method to get its value.

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As a result, the private version value cannot be copied into the Bar class when it is compiled, consequently preventing the bug. Note that most JIT code generators are capable of inlining the getVersion() method at runtime; consequently there is little or no performance penalty incurred.

Exceptions

Wiki Markup*DCL04-EX0*: According to \[[JLS 2005|AA. Bibliography#JLS 05]\], §9.3 "Field (Constant) Declarations" of the Java Language Specification [ (JLS 2005]), "Every field declaration in the body of an interface is implicitly {{public}}, {{static}}, and {{final}}. It is permitted to redundantly specify any or all of these modifiers for such fields."

DCL04-EX1: Constants declared using the enum type are permitted to violate this guideline.

DCL04-EX2: Constants whose value never changes throughout the entire lifetime of the software may be declared as final. For instance, the Java Language Specification recommends that mathematical constants be declared final.

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