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    <p>If the value assigned to a <code>static final boolean</code> field is known at compile-time, it is a <em>constant.</em> Fields of primitive or <code>String</code> type can be compile-time constants. A constant will be inlined in any code that references the field. Since the field is not actually read at runtime, changing it then will have no effect.</p> <p>The <a href="https://docs.oracle.com/javase/specs/jls/se10/html/jls-13.html#jls-13.4.9" rel="nofollow noreferrer">Java language specification</a> says this:</p> <blockquote> <p>If a field is a constant variable (§4.12.4), then deleting the keyword final or changing its value will not break compatibility with pre-existing binaries by causing them not to run, but <strong>they will not see any new value for the usage of the field unless they are recompiled.</strong> This is true even if the usage itself is not a compile-time constant expression (§15.28)</p> </blockquote> <p>Here's an example:</p> <pre><code>class Flag { static final boolean FLAG = true; } class Checker { public static void main(String... argv) { System.out.println(Flag.FLAG); } } </code></pre> <p>If you decompile <code>Checker</code>, you'll see that instead of referencing <code>Flag.FLAG</code>, the code simply pushes a value of 1 (<code>true</code>) onto the stack (instruction #3).</p> <pre><code>0: getstatic #2; //Field java/lang/System.out:Ljava/io/PrintStream; 3: iconst_1 4: invokevirtual #3; //Method java/io/PrintStream.println:(Z)V 7: return </code></pre>
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    1. POChange private static final field using Java reflection
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    1. COThat was my first thought, but then I remembered Java compiled at runtime, if you were to reset the bit it would simply recompile with it as a variable instead of a constant.
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    2. CO@Bill K - No, this doesn't refer to JIT compilation. The dependent class files will actually contain the inlined values, and no reference to the independent class. It's a pretty simple experiment to test; I will add an example.
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    3. COHow does this jive with @polygenelubricants 's answer where he redefines Boolean.false?--but you are correct, I've seen this behavior when things didn't recompile correctly.
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