Do not reuse the names of publicly-visible identifiers, public utility classes, interfaces, and or packages in the Java Standard Library.
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IfWhen a developer uses an identifier that has the same name as a public class, such as {{Vector}}, a subsequent maintainer might not be aware that this identifier does not actually refer to {{java.util.Vector}}, and might unintentionally use the custom {{Vector}} instead of the original {{java.util.Vector}} class. The custom type {{Vector}} can [shadow|BB. Definitions#shadow] a class name from {{java.util.Vector}}, as specified by [§6.3.2|http://java.sun.com/docs/books/jls/third_edition/html/names.html#6.3.2] of the _Java Language Specification_ \[[JLS 2005|AA. Bibliography#JLS 05]\]. This can result in unexpected program behavior. |
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This compliant solution uses a different name for the class, preventing any potential shadowing of the class from the Java Standard Library.
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class MyVector {
//other code
}
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When the developer and organization control the original shadowed class, it may be preferable to change the design strategy of the original in accordance with Bloch's _Effective Java_ \[[Bloch 2008|AA. Bibliography#Bloch 08]\] "Item 16: Prefer interfaces to abstract classes." Changing the original class into an interface would permit class {{MyVector}} to declare that it implements the hypothetical {{Vector}} interface. This would permit client code that intended to use {{MyVector}} to remain compatible with code that uses the original implementation of {{Vector}}. |
Risk Assessment
Name Public identifier reuse decreases the readability and maintainability of code.
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<ac:structured-macro ac:name="unmigrated-wiki-markup" ac:schema-version="1" ac:macro-id="ba1fcf8667a5d5ae-e3883c68-4bbf4999-b2f296c2-a051b10af7bf1bdf46a22be1"><ac:plain-text-body><![CDATA[ | [[JLS 2005 | AA. Bibliography#JLS 05]] | [§6.3.2, "Obscured Declarations" | http://java.sun.com/docs/books/jls/third_edition/html/names.html#6.3.2] | ]]></ac:plain-text-body></ac:structured-macro> |
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<ac:structured-macro ac:name="unmigrated-wiki-markup" ac:schema-version="1" ac:macro-id="6fe1348153ef83df-a6a57e82-4b3b4662-81b2be8b-336bf4bba8d4c030fecc1cee"><ac:plain-text-body><![CDATA[ | [[FindBugs 2008 | AA. Bibliography#FindBugs 08]] | ]]></ac:plain-text-body></ac:structured-macro> | ||
<ac:structured-macro ac:name="unmigrated-wiki-markup" ac:schema-version="1" ac:macro-id="75f6b6d1c0d01174-fa33c852-4a40486e-856786ba-213c84e894c45c3fd51055c4"><ac:plain-text-body><![CDATA[ | [[Bloch 2005 | AA. Bibliography#Bloch 05]] | Puzzle 67: All Strung Out | ]]></ac:plain-text-body></ac:structured-macro> | |
<ac:structured-macro ac:name="unmigrated-wiki-markup" ac:schema-version="1" ac:macro-id="05f70f093cf48e37-ab476264-451c4c11-91f1aaa4-73f3ea40807eb2c72c95cc5b"><ac:plain-text-body><![CDATA[ | [[Bloch 2008 | AA. Bibliography#Bloch 08]] | Item 16: Prefer interfaces to abstract classes | ]]></ac:plain-text-body></ac:structured-macro> |
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