你是否一直被入参的校验困扰，写着ifelseifelse的垃圾代码。你是否也幻想只要使用一行代码就完事，就像这样：
@RegexAnnotation(regexEnum = RegexEnum.IDENTITY, message = "身份证校验失败")
private String identity;
为了程序员的尊严，让我们学习一下这个小技能吧。
先介绍下需要引入的功能包：javax.validation.constraints
<dependency>
<groupId>javax.validation</groupId>
<artifactId>validation-api</artifactId>
<version>1.1.0.Final</version>
</dependency>
通过继承前人的注解，我们可以省略很多工作。让我们开始吧~
自定义注解：
@Target({ElementType.METHOD, ElementType.FIELD, ElementType.ANNOTATION_TYPE, ElementType.CONSTRUCTOR, ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Constraint(validatedBy = {RegexValidator.class}) // 关联RegexValidator类
public @interface RegexAnnotation {
RegexEnum regexEnum();
String message() default "校验失败";
Class<?>[] groups() default {}; // 约束注解在验证时所属的组别
Class<? extends Payload>[] payload() default {}; // 约束注解的有效负载
}
关联注解的具体逻辑校验类：
public class RegexValidator implements ConstraintValidator<RegexAnnotation, Object> {
RegexEnum regexEnum;
@Override
public void initialize(RegexAnnotation constraintAnnotation) {
regexEnum = constraintAnnotation.regexEnum();
}
@Override
public boolean isValid(Object value, ConstraintValidatorContext context) {
if(value==null){
return false;
}
Pattern pattern = Pattern.compile(regexEnum.getRegex());
return pattern.matcher(value.toString()).matches();
}
}
使用注解校验的请求类：
@Data
public class ConstraintRequest {
@NotNull(message = "id不能为空")
private String id;
@Max(value = 10, message = "name最大长度为10")
private String name;
@NotNull(message = "firstName不能为空")
@Size(min = 5, max = 9, message = "firstName长度须在5-10之间")
private String firstName;
@Pattern(regexp = "^[a-zA-Z0-9_.-]+@.*\\.[a-zA-Z0-9]{2,6}$", message = "邮箱格式错误")
private String email;
@AssertTrue(message = "flag字段须为true")
private boolean flag;
@Future(message = "时间须超过当前时间")
private Date date;
@RegexAnnotation(regexEnum = RegexEnum.IDENTITY, message = "身份证校验失败")
private String identity;
}
单测验证：
public class RegexAnnotationTest {
@Test
public void testRegex(){
ConstraintRequest request = new ConstraintRequest();
request.setName("1234567890a");
request.setDate(new Date());
request.setEmail("test");
request.setIdentity("310");
ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
Validator validator = factory.getValidator();
Set<ConstraintViolation<ConstraintRequest>> violationSet = validator.validate(request);
for (ConstraintViolation<ConstraintRequest> violation : violationSet) {
System.out.println(violation.getMessage());
}
}
}
测试输出：
INFO: HV000001: Hibernate Validator 5.2.4.Final
id不能为空
flag字段须为true
name最大长度为10
身份证校验失败
firstName不能为空
邮箱格式错误
时间须超过当前时间
学完，收工。
