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javaxpathpmd

PMD find annotation and check if has attribute

How do I write PMD rule which will search for javax.validation.constraints.NotNull annotation and validate if it has message attribute?

Bad:

@NotNull
private int value;

Good

@NotNull(message = "value cannot be null.")
private int value;

Main concern for me is that this annotation can be placed basicaly anywhere

@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER })
Solution

  • Here's the xpath query to find NotNull annotations without a message: //Annotation[*/Name/@Image = 'NotNull' and not(.//MemberValuePair/@Image = 'message')]

    I've tested all cases except for ANNOTATION_TYPE, which I'm not sure how to test in the PMD builder app.

    If you want all javax.validation.constraints I've come up with this: //Annotation[*/Name/@Image = tokenize(replace(string-join(//ImportDeclaration/Name/@Image[starts-with(., "javax.validation.constraints.")], "|"), "javax.validation.constraints.", ""), '[|]') and not(.//MemberValuePair/@Image = 'message')]

    So: take all imports that start with javax.validation.constraints., convert to string with string-join, remove javax.validation.constraints. with replace and split back into a set of values with tokenize.