1.说明

在Spring Boot已经集成Hibernate Validator校验器的情况下，
对于配置了校验注解的请求参数，
框架会自动校验其参数，
但是如果想手动校验一个加了注解的普通对象，
比如从文件中解析出来的对象，
或者自己新建的对象，
可以使用如下工具类对其进行校验。

2.工具类

通过Spring上下文获取容器中的Validator，
然后注入到本地静态变量中，
用于后续的对象校验，
ValidatorUtil.java源码：

package com.ai.ipc.resource.util;import java.util.Set;import javax.validation.ConstraintViolation;
import javax.validation.ValidationException;
import javax.validation.Validator;import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;
import org.springframework.validation.beanvalidation.LocalValidatorFactoryBean;
import org.springframework.validation.beanvalidation.SpringValidatorAdapter;/*** Hibernate Validator校验工具类*/
@Component
public class ValidatorUtil implements ApplicationContextAware {// 通过Spring获得校验器private static Validator validator;@Overridepublic void setApplicationContext(ApplicationContext applicationContext) {Validator validatorBean = applicationContext.getBean(Validator.class);setValidator(validatorBean);}public static void setValidator(Validator validatorBean) {// Unwrap to the native Validator with forExecutables supportif (validatorBean instanceof LocalValidatorFactoryBean) {validator = ((LocalValidatorFactoryBean) validatorBean).getValidator();} else if (validatorBean instanceof SpringValidatorAdapter) {validator = validatorBean.unwrap(Validator.class);} else {validator = validatorBean;}}/*** 对配置了注解的对象进行校验*/public static <T> void validate(T object) {Set<ConstraintViolation<T>> violationSet = validator.validate(object);for (ConstraintViolation<T> violation : violationSet) {// 快速返回第一个校验失败的数据throw new ValidationException(violation.getMessage());}}
}

3.使用方式

在如下Junit测试用例中，
新建了Device对象的实例，
然后用ValidatorUtil对其进行校验，
如果参数不满足校验注解，
会抛出对应的校验异常：

package com.ai.ipc.util;import javax.validation.constraints.NotEmpty;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;import com.ai.ipc.resource.ResourceApplication;
import com.ai.ipc.resource.util.ValidatorUtil;@SpringBootTest(classes = ResourceApplication.class)
public class ValidatorUtilTest {@Testpublic void testValidateBean() {Device device = new Device();device.deviceId = "d001";device.ip = "1.1.1.1";device.name = "12345";ValidatorUtil.validate(device);}public class Device {/*** 设备ID*/@NotNull(message = "deviceId不能为Null")private String deviceId;/*** 设备IP，业务主键，建立唯一索引约束，不支持修改*/@NotEmpty(message = "IP不能为空")private String ip;/*** 设备名称*/@Size(min = 1, max = 3, message = "name的长度size在[1,3]之间")private String name;}}

4.异常日志

上面测试代码填写的name长度为5，
发生异常时的日志如下：

javax.validation.ValidationException: name的长度size在[1,3]之间at com.ai.ipc.resource.util.ValidatorUtil.validate(ValidatorUtil.java:51)at com.ai.ipc.util.ValidatorUtilTest.testValidateBean(ValidatorUtilTest.java:26)at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)at java.lang.reflect.Method.invoke(Method.java:498)at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:686)at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)