如何通过Java Validator消息传递参数？

目前，我有类似的东西

@NotNull(message="{err.required}")
@Size(min=1, message="{err.required}")
private String firstName;

In my messages.properties, I have

err.required={0} is required.

它有效，但打印出来firstName is required.这很丑。它传递了变量名firstName作为参数{0}.

我如何传递类似“名” 相反？所以它会变成First name is required.

你可以这样做：

@NotNull(message="First name {err.required}")
@Size(min=1, message="First name {err.required}")
private String firstName;

@NotNull(message="Last name {err.required}")
@Size(min=1, message="Last name {err.required}")
private String lastName;

并在属性文件中

err.required= is required. 

或者如果你想更清楚，你可以添加自己的注释和验证器：

@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER })
@Retention(RUNTIME)
@Documented
@Constraint(validatedBy = { NotEmptyValidator.class })
public @interface NotEmpty {

    String message() default "{customMessage} is required.";

    Class<?>[] groups() default { };

    Class<? extends Payload>[] payload() default { };

    String customMessage() default "";
}

public class NotEmptyValidator implements ConstraintValidator<NotEmpty, String>
{
    @Override
    public void initialize(NotEmpty notEmpty)
    {        
    }

    @Override
    public boolean isValid(String value, ConstraintValidatorContext context)
    {
        return value != null && !value.isEmpty();
    }
}

那么你的领域

@NotEmpty(message="{err.required}"
          customMessage="First name")
private String firstName;

在属性中（尽管这不是强制性的，因为您可以将值默认为此）：

err.required={customMessage} is required.