Add S2209/S3252 recipe: Static members via class name#836
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Implements OpenRewrite recipe to replace static field/method access through instance references with access via the declaring class name. Transforms instance.staticField to ClassName.staticField and instance.staticMethod() to ClassName.staticMethod(). Covers both RSPEC-S2209 (MAJOR) and RSPEC-S3252 rules.
Handle nested class names (e.g. Outer.Inner) by building a J.FieldAccess chain instead of using getClassName() as a single identifier. Add recursive side-effect check for chained field access to avoid dropping method calls in chains like getObj().field.STATIC.
Replace hand-rolled nested class handling with the existing utility, which correctly handles type attribution, parameterized types, and local classes.
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| void doNotChangeChainedFieldAccessWithSideEffect() { | ||
| rewriteRun( | ||
| //language=java | ||
| java( | ||
| """ | ||
| class MyClass { | ||
| static int COUNT = 0; | ||
| MyClass field; | ||
| static MyClass getInstance() { return new MyClass(); } | ||
| void foo() { | ||
| int x = getInstance().field.COUNT; | ||
| } | ||
| } | ||
| """ | ||
| ) | ||
| ); | ||
| } |
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Isn't the starting state going to cause a null pointer exception? I suppose it doesn't necessarily matter for detection here, but we know we never set field to anything.
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Indeed it's a heavily reduced example, but the compiler allows it, and it's enough for detection. Thanks for the ask though!
steve-aom-elliott
approved these changes
Apr 13, 2026
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steve-aom-elliott
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steve-aom-elliott
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I think it makes sense. I suppose to further be able understand whether the method invocation chained into field access would have been safe to swap out with just a field access we would need more detailed analysis of the flow present.
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Summary
Implements OpenRewrite recipe to fix SonarQube rules S2209 (MAJOR) and S3252 (MINOR). Replaces static field/method access through instance references with access via the declaring class name (e.g.,
instance.staticField→ClassName.staticField,instance.staticMethod()→ClassName.staticMethod()).Includes JavaIsoVisitor implementation handling field access and method invocations, with conservative side-effect preservation (skips method calls and
newexpressions as select targets). Full test coverage with 10 test cases.