广州网站设计智能 乐云践新专家,中国广电山东网络有限公司,哪个网站可以做鞋鉴定,页面设计需求发展在使用mybatisplus自带雪花的时候会发现返回的ID是19位的长度#xff0c;因此在通过swagger页面展示的时候会发现后端返回的和页面展示的ID不一致问题。是因为精度丢失的问题。因此需要更改雪花ID的长度跟踪进去#xff1a;发现是DefaultIdentifierGenerator类实现了Identifi…在使用mybatisplus自带雪花的时候会发现返回的ID是19位的长度因此在通过swagger页面展示的时候会发现后端返回的和页面展示的ID不一致问题。是因为精度丢失的问题。因此需要更改雪花ID的长度跟踪进去发现是DefaultIdentifierGenerator类实现了IdentifierGenerator并重写了nextId方法,因此需要我们重写nextId方法
进行重写
package com.ssdl.config.automatic;import com.baomidou.mybatisplus.core.incrementer.IdentifierGenerator;
import com.ssdl.util.IdGenerator;
import org.springframework.stereotype.Component;Component
public class CustomerIdGenerator implements IdentifierGenerator {Overridepublic Number nextId(Object entity) {return IdGenerator.generateId();}
}package com.ssdl.util;import java.util.Date;
import java.util.UUID;/*** compressed id generator, result id not great than 53bits before 2318-06-04.*/
public class IdGenerator {private static IdGenerator instance new IdGenerator(0);public static IdGenerator initDefaultInstance(int machineId) {instance new IdGenerator(machineId);return instance;}public static IdGenerator getInstance() {return instance;}public static long generateId() {return instance.nextId();}// total bits53(max 2^53-19007199254740992-1)// private final static long TIME_BIT 40; // max: 2318-06-04private final static long MACHINE_BIT 5; // max 31private final static long SEQUENCE_BIT 8; // 256/10ms/*** mask/max value*/private final static long MAX_MACHINE_NUM -1L ^ (-1L MACHINE_BIT);private final static long MAX_SEQUENCE -1L ^ (-1L SEQUENCE_BIT);private final static long MACHINE_LEFT SEQUENCE_BIT;private final static long TIMESTMP_LEFT MACHINE_BIT SEQUENCE_BIT;private long machineId;private long sequence 0L;private long lastStmp -1L;private IdGenerator(long machineId) {if (machineId MAX_MACHINE_NUM || machineId 0) {throw new IllegalArgumentException(machineId cant be greater than MAX_MACHINE_NUM or less than 0);}this.machineId machineId;}/*** generate new ID** return*/public synchronized long nextId() {long currStmp getTimestamp();if (currStmp lastStmp) {throw new RuntimeException(Clock moved backwards. Refusing to generate id);}if (currStmp lastStmp) {sequence (sequence 1) MAX_SEQUENCE;if (sequence 0L) {currStmp getNextTimestamp();}} else {sequence 0L;}lastStmp currStmp;return currStmp TIMESTMP_LEFT //| machineId MACHINE_LEFT //| sequence;}private long getNextTimestamp() {long mill getTimestamp();while (mill lastStmp) {mill getTimestamp();}return mill;}private long getTimestamp() {// per 10msreturn System.currentTimeMillis() / 10;// 10ms}public static Date parseIdTimestamp(long id) {return new Date((id TIMESTMP_LEFT) * 10);}public static String uuid() {return UUID.randomUUID().toString().replaceAll(-, );}
}插曲 在使用mybatisplus时自动插入创建时间之类的操作
package com.ssdl.config.autoMatic;import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
import org.apache.ibatis.reflection.MetaObject;
import org.springframework.stereotype.Component;import java.util.Date;Component
public class MybatisHandler implements MetaObjectHandler {Overridepublic void insertFill(MetaObject metaObject) {//属性名this.setFieldValByName(createTime, new Date(), metaObject);this.setFieldValByName(updateTime, new Date(), metaObject);this.setFieldValByName(isDel, 0, metaObject);this.setFieldValByName(createUser, admin, metaObject);this.setFieldValByName(updateUser, admin, metaObject);//this.setFieldValByName(createUser, SecureUtil.getUserId(), metaObject);//不维护create_user可以不使用这行代码}Overridepublic void updateFill(MetaObject metaObject) {//属性名this.setFieldValByName(updateTime, new Date(), metaObject);this.setFieldValByName(updateUser, admin, metaObject);//this.setFieldValByName(updateUser, SecureUtil.getUserId(), metaObject);}
}TableId(value id,type IdType.ASSIGN_ID)private Long id;/*** 进行新增或者更新操作时* Mybatis自动进行维护时间*/TableField(fill FieldFill.INSERT)private String createUser;TableField(fillFieldFill.INSERT)JsonFormat(shape JsonFormat.Shape.STRING, pattern yyyy-MM-dd HH:mm:ss, timezone GMT8)private Date createTime;TableField(fillFieldFill.INSERT_UPDATE)JsonIgnoreprivate String updateUser;TableField(fill INSERT_UPDATE)JsonIgnoreprivate Date updateTime;TableLogicTableField(fill FieldFill.INSERT)JsonIgnoreprivate Integer isDel;
