public class ValidationUtil {
    private static Validator validator;
    private static Validator faliFastValidator;
    private static ExecutableValidator executableValidator;

    static {
        validator = Validation.buildDefaultValidatorFactory().getValidator();
        // 快速失败
        faliFastValidator = Validation.byProvider(HibernateValidator.class).configure().failFast(true).buildValidatorFactory().getValidator();
        // 验证非bean入参
        executableValidator = validator.forExecutables();
    }

// 方法约束校验
    public static void validateParameters(Object var1, Method var2, Object[] var3, Class<?>... var4) {
        Set<ConstraintViolation<Object>> constraintViolations = executableValidator.validateParameters(var1, var2, var3, var4);
        constraintViolations.forEach(i -> {
	// 常见是使用异常来传递错误信息
            throw new RuntimeException(i.getMessage());
        });
    }
// bean约束校验
    public static void valid(Object o) {
        Set<ConstraintViolation<Object>> validate = validator.validate(o);
        validate.stream().forEach(v -> {
            System.out.println(v.getMessage());
//            throw new RuntimeException(v.getMessage());
        });
    }
    /*
    * 与valid方法的区别，只要有一个不成立就停止循环;valid方法会打印所有不满足的信息
    * */
    public static void fastValid(Object o) {
        Set<ConstraintViolation<Object>> validate = faliFastValidator.validate(o);
        validate.stream().forEach(v -> {
            System.out.println(v.getMessage());
//            throw new RuntimeException(v.getMessage());
        });
    }
}

public class UserInfo {
    @NotBlank(message = "姓名不能为空")
    private String name;
    @Min(value = 18, message = "未成年人禁止使用")
    private int age;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

public class Main {
    public static void main(String[] args) {
        UserInfo userInfo = new UserInfo();
        userInfo.setAge(12);
        userInfo.setName("");
// 没有if语句，进行数据校验
        ValidationUtil.valid(userInfo);
//        ValidationUtil.fastValid(userInfo);

// 运行结果：
//
//一月 22, 2021 4:37:06 下午 org.hibernate.validator.internal.util.Version <clinit>
//INFO: HV000001: Hibernate Validator 6.1.6.Final
//        姓名不能为空
//        未成年人禁止使用
}

public interface IUserInfoService {
    // 校验方法参数
    void add(@NotBlank(message = "用户名不能为空") String username);
    // 校验bean约束
    void add(@Valid UserInfo userInfo);
}

public class UserInfoService implements IUserInfoService {
    public void add(String username) {
        System.out.println("添加成功["+username+"]");
    }

    @Override
    public void add(UserInfo userInfo) {
        System.out.println(userInfo);
    }
}

public class ValidatorAspect extends SimpleAspect {
    // 动态代理，在调用被代理的方法前调用
    @Override
    public boolean before(Object target, Method method, Object[] args) {
        ValidationUtil.validateParameters(target, method, args);
        return true;
    }
}

public class Main {
    public static void main(String[] args) {
	UserInfo userInfo = new UserInfo();
        userInfo.setAge(12);
        userInfo.setName("");
        // 通过动态代理创建一个对象
        IUserInfoService proxy = ProxyUtil.proxy(new UserInfoService(), ValidatorAspect.class);
        // 校验方法约束
	proxy.add("");
	// 校验bean约束
	proxy.add(userInfo);
    }
}

public class MyWebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
    @Override
    protected Class<?>[] getRootConfigClasses() {
        return null;
    }

    // 加载springmvc配置类
    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class[]{WebConfig.class};
    }
    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }
}

@Configuration
@EnableWebMvc
@ComponentScan(value = "zone.lxy",includeFilters = @ComponentScan.Filter(classes = {Controller.class}))
public class WebConfig implements WebMvcConfigurer {
    /*
    * 配置hibernate-validator，默认已经配置
    * */
//    @Override
//    public Validator getValidator() {
//        LocalValidatorFactoryBean localValidatorFactoryBean = new LocalValidatorFactoryBean();
//        localValidatorFactoryBean.setProviderClass(HibernateValidator.class);
//        return localValidatorFactoryBean;
//    }
    /*
    * 配置方法级别的数据校验，（非bean入参）
    * */
    @Bean
    public MethodValidationPostProcessor methodValidationPostProcessor() {
        return new MethodValidationPostProcessor();
    }
}

// 使用方法验证时，需要的被校验的类上添加@Validated注解
@Validated
@RestController
public class IndexController {
    
    
    /*
    * 方法约束校验
    * */
    @GetMapping("/")
    public Object index(@NotEmpty String s) {
        return s;
    }

    /*
    * bean约束校验
    * */
    @RequestMapping("/user")
    public User info(@Valid User user) {
        return user;
    }
}