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e21cbe82a9
Where possible update Java documentation links to Java 11. Additionally update some other links to use HTTPS.
43 lines
1.0 KiB
XML
43 lines
1.0 KiB
XML
<!DOCTYPE qhelp PUBLIC
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"-//Semmle//qhelp//EN"
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"qhelp.dtd">
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<qhelp>
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<overview>
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<p>
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Sometimes you can guarantee that a particular variable will never be null.
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For example when that variable has just been assigned a newly created
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object or is the exception caught by a <code>catch</code> clause.
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A null check on such a variable is misleading, and can potentially indicate a
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logic error.
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</p>
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</overview>
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<recommendation>
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<p>
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Do not check a variable for null if a null value is clearly impossible.
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</p>
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</recommendation>
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<example>
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<p>
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The following example shows a null check on a newly created object. An object
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returned by <code>new</code> can never be null, so this check is superfluous.
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</p>
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<sample src="UselessNullCheckBad.java" />
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</example>
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<references>
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<li>
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Java Language Specification:
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<a href="https://docs.oracle.com/javase/specs/jls/se11/html/jls-12.html#jls-12.5">Creation of New Class Instances</a>,
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<a href="https://docs.oracle.com/javase/specs/jls/se11/html/jls-14.html#jls-14.20.1">Execution of try-catch</a>.
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</li>
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</references>
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</qhelp>
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