我想使用Jersey中的多部分表单数据来验证要上传的图像的文件扩展名。我创建了一个自定义批注ImageExtensionValidator
:
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import java.util.regex.Pattern;
import javax.validation.Constraint;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import javax.validation.Payload;
@Retention(RUNTIME)
@Target({ FIELD, PARAMETER })
@Constraint(validatedBy = { ImageExtensionValidator.Validator.class })
public @interface ImageExtensionValidator {
String message() default "Please Enter valid Image";
String url() default "";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
class Validator implements ConstraintValidator<ImageExtensionValidator, String> {
private String constraintMessage;
private String fileName;
Pattern pattern = Pattern.compile("\\.(?:jpg|gif|png|jpeg|JPG|GIF|PNG|JPEG)");
@Override
public void initialize(ImageExtensionValidator constraintAnnotation) {
constraintMessage = constraintAnnotation.message();
fileName = constraintAnnotation.url();
}
@Override
public boolean isValid(String value, ConstraintValidatorContext context) {
if (value == null || value.trim().isEmpty()) {
return true;
} else if (pattern.matcher(value.trim()).matches()) {
return true;
} else {
context.disableDefaultConstraintViolation();
context.buildConstraintViolationWithTemplate(constraintMessage).addConstraintViolation();
return false;
}
}
}
}
并且像这样使用它:
@FormDataParam("logo")
private InputStream logoStream;
@ImageExtensionValidator
@FormDataParam("logo")
private FormDataContentDisposition logoDetails;
使用此工具时出现以下错误:
javax.validation.UnexpectedTypeException: HV000030: No validator could be found for type: org.glassfish.jersey.media.multipart.FormDataContentDisposition.
我知道还有其他方法可以做到。但是这样的事情会使我的代码更整洁。预先感谢。
在Paul发表评论后,我在ImageExtensionValidator代码中发现一个错误。该类应定义为:
class Validator implements ConstraintValidator<ImageExtensionValidator, FormDataContentDisposition>