全局唯一化 主键

用户的主键

1、全局唯一化。已经把组件预先的引用了进来。就是下面三个包，

2、这里有个sid，其实就是工具类。

package org.n3r.idworker;

import org.n3r.idworker.strategy.DefaultWorkerIdStrategy;
import org.n3r.idworker.utils.Utils;
import org.springframework.stereotype.Component;

import java.text.SimpleDateFormat;
import java.util.Date;

@Component
public class Sid {
    private static WorkerIdStrategy workerIdStrategy;
    private static IdWorker idWorker;

    static {
        configure(DefaultWorkerIdStrategy.instance);
    }


    public static synchronized void configure(WorkerIdStrategy custom) {
        if (workerIdStrategy != null) workerIdStrategy.release();
        workerIdStrategy = custom;
        idWorker = new IdWorker(workerIdStrategy.availableWorkerId()) {
            @Override
            public long getEpoch() {
                return Utils.midnightMillis();
            }
        };
    }

    /**
     * 一天最大毫秒86400000，最大占用27比特
     * 27+10+11=48位 最大值281474976710655(15字)，YK0XXHZ827(10字)
     * 6位(YYMMDD)+15位，共21位
     *
     * @return 固定21位数字字符串
     */

    public static String next() {
        long id = idWorker.nextId();
        String yyMMdd = new SimpleDateFormat("yyMMdd").format(new Date());
        return yyMMdd + String.format("%014d", id);
    }


    /**
     * 返回固定16位的字母数字混编的字符串。
     */
    public String nextShort() {
        long id = idWorker.nextId();
        String yyMMdd = new SimpleDateFormat("yyMMdd").format(new Date());
        return yyMMdd + Utils.padLeft(Utils.encode(id), 10, '0');
    }
    
//    public static void main(String[] args) {
//        String aa = new Sid().nextShort();
//        String bb = new Sid().next();
//
//        System.out.println(aa);
//        System.out.println(bb);
//    }
}

3、这三个包包是org.n3r.idworker。要想注入进来。就必须包能被容器扫描到。

package com.imooc;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import tk.mybatis.spring.annotation.MapperScan;

@SpringBootApplication
@MapperScan(basePackages = "com.imooc.mapper")
@ComponentScan(basePackages = {"com.imooc","org.n3r.idworker"})
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class,args);
    }
}

4、这样sid就已经注入进来，可以用了。

package com.imooc.service.impl;


import com.imooc.enums.Sex;
import com.imooc.mapper.UsersMapper;
import org.n3r.idworker.Sid;
import com.imooc.pojo.Users;
import com.imooc.pojo.bo.UserBO;
import com.imooc.service.UserService;
import com.imooc.utils.DateUtil;
import com.imooc.utils.MD5Utils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
import tk.mybatis.mapper.entity.Example;

import java.util.Date;


@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UsersMapper usersMapper;

    @Autowired
    private Sid sid;

    private static final String USER_FACE="";
    @Transactional(propagation = Propagation.SUPPORTS)

    @Override
    public boolean queryUsernameIsExist(String username) {
//        try {
//            Thread.sleep(3500);
//        } catch (InterruptedException e) {
//            e.printStackTrace();
//        }
        Example userExample = new Example(Users.class);
        Example.Criteria criteria = userExample.createCriteria();
        criteria.andEqualTo("username", username);
        Users result=usersMapper.selectOneByExample(userExample);
        return result==null ? false : true;
    }

    @Transactional(propagation = Propagation.REQUIRED)
    @Override
    public Users creatUser(UserBO userBO) {

        String userId= sid.nextShort();
        Users user=new Users();
        user.setId(userId);
        user.setUsername(userBO.getUsername());
        try {
            user.setPassword(MD5Utils.getMD5Str(userBO.getPassword()));
        }catch (Exception e) {
            e.printStackTrace();
        }
        user.setNickname(userBO.getUsername());
        user.setFace(USER_FACE);
        user.setBirthday(DateUtil.convertToDate("1900-1-1"));
        user.setSex(Sex.secret.type);
        user.setCreatedTime(new Date());
        user.setUpdatedTime(new Date());
        usersMapper.insert(user);
        return user;
    }


    @Transactional(propagation = Propagation.SUPPORTS)
    @Override
    public Users queryUserForLogin(String username, String password) {
        Example userExample = new Example(Users.class);
        Example.Criteria criteria = userExample.createCriteria();
        criteria.andEqualTo("username", username);
        criteria.andEqualTo("password",password);
        Users result=usersMapper.selectOneByExample(userExample);
        return result;

    }
}