一、脚本部分

1. 表结构

有注释

-- Create table
create table LDMAXNO
(NOTYPE  VARCHAR2(17) not null,NOLIMIT VARCHAR2(12) not null,MAXNO   INTEGER not null
);
-- Add comments to the table 
comment on table LDMAXNOis '产生最大的流水号，所有的号码从1开始';
-- Add comments to the columns 
comment on column LDMAXNO.NOTYPEis '含义描述:1、号码类型';
comment on column LDMAXNO.NOLIMITis '含义描述:1、号码限制条件';
comment on column LDMAXNO.MAXNOis '含义描述:1、当前最大值';
-- Create/Recreate primary, unique and foreign key constraints 
alter table LDMAXNOadd constraint PK_LDMAXNO primary key (NOTYPE, NOLIMIT);

2. 函数

  create or replace function CreateMaxNos(cNoType  in ldmaxno.notype%type,cNoLimit in ldmaxno.nolimit%type)return integer ispragma autonomous_transaction;tMaxNo integer := 0; --初始化赋值等于0，定义返回变量begin--最大数加1update LDMaxNoset MaxNo = MaxNo + 1where NoType = cNoTypeand NoLimit = cNoLimitReturning MaxNo Into tMaxNo; --取出最大数If (Sql%Notfound) then--第一次向数据库中插入最大数为 1 的记录Insert Into LDMaxNo(NOTYPE, NOLIMIT, MAXNO)values(cNoType, cNoLimit, 1);tMaxNo := 1;End If;commit;return(tMaxNo); --返回结果
end CreateMaxNos;
/

二、代码部分

2.1. xml

DullMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.gblfy.business.mapper.DullMapper"><select id="getMaxNo" resultType="java.lang.String">select createmaxno(#{cNoType},#{cNoLength}) from dual</select>
</mapper>

2.2. 接口

DullMapper.java

package com.gblfy.business.mapper;import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Param;public interface DullMapper extends BaseMapper {/*** 功能：产生指定长度的流水号，一个号码类型一个流水* @param cNoType 流水号的类型* @param cNoLength 流水号的长度* @return 返回产生的流水号码*/String getMaxNo(@Param("cNoType") String cNoType, @Param("cNoLength") int cNoLength);
}

2.3. api接口

package com.gblfy.business.service;public interface SysMaxNoService {/*** 功能：产生指定长度的流水号，一个号码类型一个流水** @param cNoType   流水号的类型* @param cNoLength 流水号的长度* @return 返回产生的流水号码*/String createMaxNo(String cNoType, int cNoLength);
}

2.4. api实例

package com.gblfy.business.service.impl;import com.gblfy.business.mapper.DullMapper;
import com.gblfy.business.service.SysMaxNoService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Service;import javax.annotation.Resource;
import java.math.BigInteger;@Service
public class SysMaxNoServiceImpl implements SysMaxNoService {private final static Logger logger = LoggerFactory.getLogger(SysMaxNoServiceImpl.class);@Resourceprivate DullMapper dullMapper;/*** 功能：产生指定长度的流水号，一个号码类型一个流水** @param cNoType   流水号的类型* @param cNoLength 流水号的长度* @return 返回产生的流水号码*/@Overridepublic String createMaxNo(String cNoType, int cNoLength) {if ((cNoType == null) || (cNoType.trim().length() <= 0) ||(cNoLength <= 0)) {logger.info("NoType长度错误 {} NoLength错误", cNoType, cNoLength);return null;}cNoType = cNoType.toUpperCase();String tReturn = "";String cNoLimit = "SN";BigInteger tMaxNo = new BigInteger("0");tReturn = cNoLimit;try {String result = dullMapper.getMaxNo(cNoType, cNoLength);tMaxNo = new BigInteger(result);} catch (Exception e) {e.printStackTrace();logger.info("生成流水号出现异常，请核实！");}String tStr = tMaxNo.toString();//将生成的流水号进行加工处理tStr = LCh(tStr, "0", cNoLength);tReturn = tStr.trim();return tReturn;}/*** 将生成的流水号进行加工处理* <p>* 1.判断是否满足指定长度，如果不满足前面用0来补位* 2.将生成的流水号进行去空格处理* 3.将最终的流水号进行字符串拼接* </P>** @param sourString* @param cChar* @param cLen* @return*/private String LCh(String sourString, String cChar, int cLen) {int tLen = sourString.length();int i, iMax;String tReturn = "";if (tLen >= cLen) {return sourString;}//1.判断是否满足指定长度，如果不满足前面用0来补位iMax = cLen - tLen;for (i = 0; i < iMax; i++) {tReturn += cChar;}//2.将生成的流水号进行去空格处理//3.将最终的流水号进行字符串拼接tReturn = tReturn.trim() + sourString.trim();return tReturn;}
}

2.5. 控制层

package com.gblfy.business.controller;import com.gblfy.business.service.SysMaxNoService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;/*** 生成指定类型+位数的流水号** @Author gblfy* @Date 2022-05-16 20:13**/
@RestController
public class SysMaxNoController {@Autowiredprivate SysMaxNoService maxNoService;/*** 生成指定类型+位数的流水号** @param cNoType* @param cNoLength* @return*/@GetMapping("/generate/serial/number")public String generateSerialNumber(@RequestParam(name = "cNoType", required = false, defaultValue = "cNoType") String cNoType,@RequestParam int cNoLength) {return maxNoService.createMaxNo(cNoType, cNoLength);}
}

三、测试

3.1. 效果图