net.unmz.java.util.data.DataLengthCheckHelper Maven / Gradle / Ivy
package net.unmz.java.util.data;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
/**
* Project Name:
* 功能描述： 本文方法节选自网络,略有修改
* 原文地址:https://blog.csdn.net/lupengfei1009/article/details/80540479
*
* @author [email protected]
* @version 1.0
* @date 2018-10-15 11:42
* @since JDK 1.8
*/
public class DataLengthCheckHelper {
/**
* 校验数据属性至
*
* @param obj
* @throws IllegalArgumentException
*/
public static void validateAttributeValueLength(Object obj) throws IllegalArgumentException {
if (null != obj) {
Class cls = obj.getClass();
Field[] fields = cls.getDeclaredFields();
for (int i = 0; i < fields.length; i++) {// 遍历
try {
Field field = fields[i];
Annotation[] annotations = field.getAnnotations();
ValidateLength dataLength = null;
for (Annotation annotation : annotations)
if (annotation instanceof ValidateLength)
dataLength = (ValidateLength) annotation;
if (null != dataLength) {
field.setAccessible(true); // 打开私有访问
String name = field.getName();// 获取属性
Object value = field.get(obj);// 获取属性值
if (value == null && !dataLength.nullable())
throw new IllegalArgumentException(name + " is null");
int length = dataLength.value();// 指定的长度
int valueLength = 0;// 数据的长度
String data;
if (value instanceof String) {// 一个个赋值
data = (String) value;
valueLength = data.length();
}
if (valueLength > length)
throw new IllegalArgumentException(name + " length:" + valueLength + " too long");
}
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
}
}
}