1.自定义注解

@Documented@Retention(RetentionPolicy.RUNTIME)@Target(ElementType.FIELD)public @interface FieldConstraints {    /**     * 字段长度判断.     * @return 返回限制长度.     */    int limitLen() default 50;    /**     * 是否必填判断.     * @return 限制是否为空.     */    boolean isNotBlank() default false;    /**     * 是否必填判断.     * @return 限制是否为空.     */    boolean isNotNull() default false;    /**     * @return     */    /* 规则校验类. */    Class ruleValidate() default NoSuchValidateRule.class;}

2.引入自定义注解

@Setter@Getter@ToStringpublic class RuleVo {    /**     * 调用测系统来源.     */    @FieldConstraints(limitLen = 50,isNotBlank = true,ruleValidate = IdSoaValidateRule.class)    private String systemId;    /**     * 调用方     */    @FieldConstraints(limitLen = 50,isNotBlank = true)    private String appKey;    /**     * 调用方     */    @FieldConstraints(limitLen = 50,isNotBlank = true, ruleValidate = CorValidateRule.class )    private String pin;    @FieldConstraints(limitLen = 5000,isNotBlank = true)    private String mobile;    @FieldConstraints(limitLen = 20,isNotBlank = true, ruleValidate = kuValidateRule.class)    private String sku;    /**     * 用户的ip地址.     */    @FieldConstraints(limitLen = 30,isNotBlank = true)    private String userIp;}

3.传入对象根据注解校验

public 
     
        void validateFieldInfo(T t) throws ParamErrorException {        if (null == t) {            throw new ParamErrorException("校验参数(validateFieldInfo)参数为空.");        }        Field[] fields = t.getClass().getDeclaredFields();        if (null == fields) {            log.error("校验参数(validateFieldInfo)请求实体参数为空.");            throw new ParamErrorException("校验参数(validateFieldInfo)请求实体参数为空.");        }        for (Field field : fields) {            field.setAccessible(true);            try {                boolean ruleFlag = field.isAnnotationPresent(FieldConstraints.class);                if (ruleFlag) {                    FieldConstraints fieldRule = field.getAnnotation(FieldConstraints.class);                    //本来是注解必填才可以处理下边的规则，但是有些情况是可以不填，但是填了必须填正确.//                    if (!fieldRule.isBlank()) {//                        continue;//                    }                    // 如果类型是String  如果type是类类型，则前面包含"class "，后面跟类名                    if (field.getGenericType().toString().equals("class java.lang.String")) {                        fetchStringField(field, fieldRule, t);                    } else {
                            log.warn("入参属性值" + field.getName() + "未被处理.");                    }                }else{                    log.debug("入参属性值" + field.getName() + "未被处理.");                }            } catch (Exception ex) {                log.error("处理入参属性为:{}异常!{}", new Object[]{field.getName(), ex.getMessage()});                throw new ParamErrorException("入参属性值" + field.getName() + "校验异常."+ex.getMessage(), ex);            }        }    }
     

 

private 
     
       void fetchStringField(Field field, FieldConstraints fieldRule, T t) throws Exception {            String value = (String) field.get(t);            if (fieldRule.isNotBlank() && StringUtil.isBlank(value)) {                throw new ParamErrorException("入参属性值" + field.getName() + "不能为空.");            }            if (fieldRule.isNotNull() && null == value) {                throw new ParamErrorException("入参属性值" + field.getName() + "不能为空.");            }            if ((fieldRule.isNotBlank() || fieldRule.isNotNull()) && value.length() > fieldRule.limitLen()) {                throw new ParamErrorException("入参属性值" + field.getName() + "长度超限.value:" + value);            }            if (fieldRule.ruleValidate().getName().endsWith(NoSuchValidateRule.class.getName())) {                return;            }            ValidateRule validateRule = (ValidateRule) SpringContextHolder.getBean(fieldRule.ruleValidate());            validateRule.validateTByRule(value);    }