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="667bcfdcb26fa361-2d1b08e7-48a2468f-ab23a092-6eadfda52e393d7ee11b9793"><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="e957b8692331cd58-7c071591-427f4abf-9b3991b1-d2f7b0569caba49060dd03be"><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="f4c38bd70e02d37f-1de9526e-469f48cc-9b41b778-222c9b7ae21dba464d0ae2b3"><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="00c2d8e83e4e5e7f-eb4a66a5-43184e78-9ac5b312-0c7b4211a966975878d6a4fe"><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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