时间格式 注解 验证

EnumValid.java

@Constraint(validatedBy = DateFormatValidator.class)
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface DateFormat {
	String message() default "";

	String pattern() default "yyyy-MM-dd HH:mm:ss";

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

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

校验器EnumValidator.java

public class DateFormatValidator implements ConstraintValidator<DateFormat, String> {
	private String pattern;

	@Override
	public void initialize(DateFormat dateFormat) {
		this.pattern = dateFormat.pattern();
	}

	@Override
	public boolean isValid(String value, ConstraintValidatorContext context) {
		boolean isValid = (value == null) || isValid(value);
		if (!isValid) {
			throw new RuntimeException("invalid input parameter.");
		}
		return isValid;
	}

	private boolean isValid(String value) {
		boolean isValid = true;
		try {
			String time = URLDecoder.decode(value, "UTF-8");
			if (pattern.length() != time.length()) {
				isValid = false;
			} else {
				SimpleDateFormat dateFormat = new SimpleDateFormat(pattern);
				dateFormat.setLenient(false);
				dateFormat.parse(time);
			}
		} catch (Exception e) {
			isValid = false;
		}
		return isValid;
	}

}

使用的时候，注解作用在DTO字段上：

public class RequestDto {

  @DateFormat(pattern = "yyyy-MM-dd")
  private String data;
}