57 lines
1.3 KiB
Java
57 lines
1.3 KiB
Java
// reuse/FinalOverridingIllusion.java
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// (c)2016 MindView LLC: see Copyright.txt
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// We make no guarantees that this code is fit for any purpose.
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// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
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// It only looks like you can override
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// a private or private final method.
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class WithFinals {
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// Identical to "private" alone:
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private final void f() {
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System.out.println("WithFinals.f()");
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}
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// Also automatically "final":
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private void g() {
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System.out.println("WithFinals.g()");
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}
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}
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class OverridingPrivate extends WithFinals {
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private final void f() {
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System.out.println("OverridingPrivate.f()");
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}
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private void g() {
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System.out.println("OverridingPrivate.g()");
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}
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}
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class OverridingPrivate2 extends OverridingPrivate {
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public final void f() {
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System.out.println("OverridingPrivate2.f()");
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}
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public void g() {
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System.out.println("OverridingPrivate2.g()");
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}
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}
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public class FinalOverridingIllusion {
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public static void main(String[] args) {
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OverridingPrivate2 op2 = new OverridingPrivate2();
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op2.f();
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op2.g();
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// You can upcast:
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OverridingPrivate op = op2;
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// But you can't call the methods:
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//! op.f();
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//! op.g();
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// Same here:
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WithFinals wf = op2;
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//! wf.f();
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//! wf.g();
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}
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}
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/* Output:
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OverridingPrivate2.f()
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OverridingPrivate2.g()
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*/
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