Java has the Boolean type, so you actually have the keywords 'true' and 'false' in your code. C, for example, doesn't so it doesn't evaluate to 0. C doesn't have the Boolean type, it's just an int.

This suggests an ambiguity in how Spring’s Java Bean property resolution handles boolean properties with is prefixes. This issue was also reported to Thymeleaf, but it may originate from Spring’s ...