我知道这是一个古老的问题但对于googlers来说......

I know this is a kind of old question but, for googlers...

你应该使用 addValidators 而不是 setValidator 。如下所示：

you should use addValidators instead of setValidator. Like following:

@InitBinder
protected void initBinder(final WebDataBinder binder) {
    binder.addValidators(yourCustomValidator, anotherValidatorOfYours);
}

PS： addValidators 接受多个参数（省略号）

PS: addValidators accepts multiple parameters (ellipsis)

如果你签出 org.springframework.validation.DataBinder 的来源，你会看到：

if you checkout the source of org.springframework.validation.DataBinder you will see:

public class DataBinder implements PropertyEditorRegistry, TypeConverter {

    ....

    public void setValidator(Validator validator) {
        assertValidators(validator);
        this.validators.clear();
        this.validators.add(validator);
    }

    public void addValidators(Validator... validators) {
        assertValidators(validators);
        this.validators.addAll(Arrays.asList(validators));
    }

    ....

}

如您所见 setValidator 清除现有（默认）验证器，因此 @Valid 注释将无效预期。

as you see setValidator clears existing (default) validator so @Valid annotation won't work as expected.