47 lines
1.5 KiB
Plaintext
47 lines
1.5 KiB
Plaintext
== Why is this an issue?
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It's almost always a mistake to compare two instances of ``++java.lang.String++`` or boxed types like ``++java.lang.Integer++`` using reference equality ``++==++`` or ``++!=++``, because it is not comparing actual value but locations in memory.
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=== Noncompliant code example
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[source,java]
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----
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String firstName = getFirstName(); // String overrides equals
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String lastName = getLastName();
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if (firstName == lastName) { ... }; // Non-compliant; false even if the strings have the same value
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----
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=== Compliant solution
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[source,java]
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----
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String firstName = getFirstName();
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String lastName = getLastName();
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if (firstName != null && firstName.equals(lastName)) { ... };
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----
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== Resources
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* CWE - https://cwe.mitre.org/data/definitions/595[CWE-595 - Comparison of Object References Instead of Object Contents]
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* CWE - https://cwe.mitre.org/data/definitions/597[CWE-597 - Use of Wrong Operator in String Comparison]
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* https://wiki.sei.cmu.edu/confluence/x/UjdGBQ[CERT, EXP03-J.] - Do not use the equality operators when comparing values of boxed primitives
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* https://wiki.sei.cmu.edu/confluence/x/yDdGBQ[CERT, EXP50-J.] - Do not confuse abstract object equality with reference equality
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ifdef::env-github,rspecator-view[]
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'''
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== Comments And Links
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(visible only on this page)
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=== relates to: S1698
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=== on 31 Oct 2018, 17:41:57 Tibor Blenessy wrote:
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RSPEC-1698 has to exclude ``++java.lang.String++`` and boxed types to not raise duplicate issues
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endif::env-github,rspecator-view[]
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