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This article introduces the relevant knowledge of "how to implement the Java object data verification tool class VerifyUtils". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

Background introduction

Excel data import is a very common function, but in many cases, the data imported by customers may not be stored in the database, such as long fields and wrong types. Wait. When the product manager proposes to do data verification, do you want a field to check? And there are dozens of tables in the system that need similar functions, not to mention thousands of pieces of data imported by customers, it must be unfriendly to prompt a field error every time. The request is to remind excel of what went wrong in some fields of a line.

1. Annotation class import java.lang.annotation.*;/** * @ author Gaoyang * @ date 2020-9-2 * @ jdk.version 1.8 * @ desc javaBean check note * / @ Target ({ElementType.FIELD}) @ Retention (RetentionPolicy.RUNTIME) @ Inherited@Documentedpublic @ interface Verify {/ * field name: * @ return * / String name () default "" / * * the maximum length of 0 will not take effect until the check is greater than 0 * @ return * / int maxLength () default 0; / * required * @ return * / boolean required () default false; / * whether it contains the special character * @ return * / boolean specialCharacters () default false / * Digital verification * @ return * / boolean number () default false; / * regular * @ return * / Regexp regexp () default @ Regexp ();} / * * @ author Gaoyang * @ date 2020-9-2 * @ jdk.version 1.8 * @ desc for verifying the regular annotation class * / public @ interface Regexp {String regexp () default " String message () default "";} 2. Check tool class import cn.hutool.core.util.NumberUtil;import cn.hutool.core.util.ReUtil;import cn.hutool.core.util.ReflectUtil;import org.apache.commons.lang3.StringUtils;import java.lang.reflect.Field;import java.util.ArrayList;import java.util.List / * * @ author Gaoyang * @ Type VerifyUtils.java * @ date 2020-9-2 * @ jdk.version 1.8 * @ desc javaBean Verification tools * / @ Verify (maxLength = 10, required = true, number = true) / / private String f32 rampant Universe verify (regexp = @ Regexp (regexp = "\\ w + [\ u4E00 -\ u9FFF] +\\ d +", message = "regular mismatch"), specialCharacters = true) / / private String f33 Public class VerifyUtils {/ * check object * * @ param obj object * @ return error message * / public static List verify (Object obj) {List stringList = new ArrayList (); Field [] fields = obj.getClass () .getDeclaredFields () For (Field f: fields) {if (f.isAnnotationPresent (Verify.class)) {StringBuilder stringBuilder = new StringBuilder (); Verify verify = f.getAnnotation (Verify.class); Object object = ReflectUtil.getFieldValue (obj, f.getName ()); String value = null; if (object! = null) value = object.toString () If (verify.required ()) {if (StringUtils.isBlank (value)) {stringBuilder.append ("Field cannot be empty |") }} if (StringUtils.isNotBlank (value)) {if (verify.specialCharacters ()) {if (value.contains ("|) | | value.contains ("'") | | value.indexOf ('") >-1) {stringBuilder .append ("contains illegal characters |") } if (value.length ()! = value.trim () .length ()) {stringBuilder.append ("cannot contain spaces before and after |") }} if (verify.maxLength () > 0) {if (value.length () > verify.maxLength ()) {stringBuilder.append ("content length is too long |") }} if (verify.number ()) {if (! NumberUtil.isNumber (value)) {stringBuilder.append ("not a numeric type |") } Regexp regexp = verify.regexp (); if (StringUtils.isNotBlank (regexp.regexp () {boolean isMatch = ReUtil.isMatch (regexp.regexp (), value) If (! isMatch) {stringBuilder.append (regexp.message ()) .append ("|");} if (StringUtils.isNotBlank (stringBuilder.toString () {String name = verify.name () If (StringUtils.isBlank (name)) {name = f.getName ();} String message = name + ":" + stringBuilder.substring (0, stringBuilder.toString (). Length ()-1); stringList.add (message) } return stringList;}} 3. test

At present, only non-empty, type, length and special characters have been done, and the current implementation is only to meet the business needs of the company, which can be modified and improved if necessary.

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