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Parameter verification in JAVA by Hibernate Validation

  • 2021-07-18 07:58:38
  • OfStack

When developing JAVA server-side code, we will encounter verifying the validity of externally transmitted parameters, while hibernate-validator provides some common parameter verification comments, which we can use.

1. Introduce jar corresponding to hibernate-validator into maven: 


<dependency>
  <groupId>org.hibernate</groupId>
  <artifactId>hibernate-validator</artifactId>
  <version>4.3.1.Final</version> 
</dependency>

2. Define the fields to validate in Model: 


import javax.validation.constraints.Pattern;
import javax.validation.constraints.Size;
import org.hibernate.validator.constraints.NotEmpty;
 
public class PayRequestDto {
   
  /**
   *  Payment completion time 
   **/
  @NotEmpty(message=" Payment Completion Time cannot be empty ")
  @Size(max=14,message=" Payment completion time cannot exceed {max} Bit ")
  private String payTime;
   
  /**
   *  Status 
   **/
  @Pattern(regexp = "0[0123]", message = " Status can only be 00 Or 01 Or 02 Or 03")
  private String status;
 
  public String getPayTime() {
    return payTime;
  }
 
  public void setPayTime(String payTime) {
    this.payTime = payTime;
  }
 
  public String getStatus() {
    return status;
  }
 
  public void setStatus(String status) {
    this.status = status;
  }
}

3. Define the Validation tool class: 


import java.util.Set;
import javax.validation.ConstraintViolation;
import javax.validation.Validation;
import javax.validation.Validator;
import org.hibernate.validator.HibernateValidator;
import com.atai.framework.lang.AppException;
public class ValidationUtils {
  
  /**
   *  Use hibernate To validate the annotations of 
   * 
   */
  private static Validator validator = Validation
      .byProvider(HibernateValidator.class).configure().failFast(true).buildValidatorFactory().getValidator();
  /**
   *  Functional description : <br>
   *  Annotation Validation Parameters 
   *
   * @param obj
   * @see [ Correlation class / Method ]( Optional )
   * @since [ Products / Module version ]( Optional )
   */
  public static <T> void validate(T obj) {
    Set<ConstraintViolation<T>> constraintViolations = validator.validate(obj);
    //  Throw a check exception 
    if (constraintViolations.size() > 0) {
      throw new AppException("0001", String.format(" Parameter verification failed :%s", constraintViolations.iterator().next().getMessage()));
    }
  }
}

4. Call the tool class in the code for parameter validation: 


ValidationUtils.validate(requestDto);

The following is a description of some annotations in hibernate-validator:

@AssertTrue 用于boolean字段，该字段只能为true  
@AssertFalse 该字段的值只能为false
@CreditCardNumber 对信用卡号进行1个大致的验证
@DecimalMax 只能小于或等于该值
@DecimalMin 只能大于或等于该值
@Digits(integer=,fraction=) 检查是否是1种数字的整数、分数,小数位数的数字
@Email 检查是否是1个有效的email地址
@Future 检查该字段的日期是否是属于将来的日期
@Length(min=,max=) 检查所属的字段的长度是否在min和max之间,只能用于字符串
@Max 该字段的值只能小于或等于该值
@Min 该字段的值只能大于或等于该值
@NotNull 不能为null
@NotBlank 不能为空，检查时会将空格忽略
@NotEmpty 不能为空，这里的空是指空字符串
@Null 检查该字段为空
@Past 检查该字段的日期是在过去
@Pattern(regex=,flag=) 被注释的元素必须符合指定的正则表达式
@Range(min=,max=,message=) 被注释的元素必须在合适的范围内
@Size(min=, max=) 检查该字段的size是否在min和max之间，可以是字符串、数组、集合、Map等
@URL(protocol=,host,port) 检查是否是1个有效的URL，如果提供了protocol，host等，则该URL还需满足提供的条件
@Valid 该注解主要用于字段为1个包含其他对象的集合或map或数组的字段，或该字段直接为1个其他对象的引用，这样在检查当前对象的同时也会检查该字段所引用的对象

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