Spring控制器：尽管@valid和@size，但RequestParam未被验证

Question

@GetMapping("/search")
    public List<Result> search(@RequestParam @Valid @NotNull @Size(min = 4) String query) {
        return searchService.search(query);
    }

"/search"             --> actual 400 Bad Request, test passes
"/search?query="      --> actual 200 Ok, expected 400 because @Size(min=4)
"/search?query=a"     --> actual 200 Ok, expected 400 because @Size(min=4)
"/search?query=ab"    --> actual 200 Ok, expected 400 because @Size(min=4)
"/search?query=abc"   --> actual 200 Ok, expected 400 because @Size(min=4)
"/search?query=abcd"  --> actual 200 Ok, test passes

为什么@size(min=4)注释被忽略？

Answer 1

验证RequestParameters并不像开箱即用那样工作。

您可以将参数包装在类中，如

class SearchRequest {
    @Size(min=4)
    @NotNull
    private String query;
    ...
}

然后将控制器代码更改为

@GetMapping("/search")
public List<Result> search(@ModelAttribute @Valid SearchRequest searchRequest) {
    return searchService.search(searchRequest.getQuery());
}