javax校验工具类

JavaxValidateUtil.java

import org.hibernate.validator.HibernateValidator;
import javax.validation.ConstraintViolation;
import javax.validation.Validation;
import javax.validation.Validator;
import java.util.Objects;
import java.util.Set;

/**
 * javax校验工具类
 *
 * <p>
 * 目前只实现了fail-fast的一些校验方法，如果需要fail-over的，添加以下代码，模仿已有的方法写几个方法即可
 *
 * <pre>{@code
 *       // fail-over校验器(出错不退出而继续)
 *       private static final Validator FAIL_OVER_VALIDATOR = buildValidator(false);
 * }</pre>
 *
 * @author yanganyu
 */
public class JavaxValidateUtil {
    /**
     * fail-fast校验器 (出错即退出)
     */
    private static final Validator FAIL_FAST_VALIDATOR = buildValidator(true);

    private static Validator buildValidator(boolean failFast) {
        return Validation.byProvider(HibernateValidator.class)
                .configure()
                .failFast(failFast)
                .buildValidatorFactory()
                .getValidator();
    }

    private JavaxValidateUtil() {
    }


    /**
     * fail-fast校验并获取错误信息，即发现一个错误则停止校验
     *
     * @param <T>    目标对象类型
     * @param groups 校验器分组
     * @param target 校验目标对象
     * @return null if has no error, or else return just one error message
     */
    public static <T> String failFastValidateAndGet(T target, Class<?>... groups) {
        Objects.requireNonNull(target, "target can not be null");
        Set<ConstraintViolation<T>> constraintViolations = FAIL_FAST_VALIDATOR.validate(target, groups);
        // 由于是fail-fast，'constraintViolations.size()'只可能为0或1
        if (constraintViolations.size() > 0) {
            return constraintViolations.iterator().next().getMessage();
        } else {
            return null;
        }
    }
}