SpringBoot+Mysql+ pessimistic lock/optimistic lock to achieve snatching red packets

• RedPacketController

@RestController
@RequestMapping("redPacket")
public class RedPacketController {

    @Resource
    RedPacketService redPacketService;

    @GetMapping("/getRedPacket/{id}")
    public RedPacket getRedPacket(@PathVariable Long id){
        returnredPacketService.getRedPacket(id); }}Copy the code

• UserRedPacketController

@RestController
@RequestMapping("userRedPacket")
public class UserRedPacketController {


    @Resource
    UserRedPacketService userRedPacketService;

    @GetMapping("/grapRedPacket")
    public FrontResult grapRedPacket(Long redPacketId, Long userId){
        / / a red envelope
        int result = userRedPacketService.grapRedPacket(redPacketId, userId);
        if (result > 0) {return FrontResult.getSuccessResultOnlyMessage("Grab the red envelope successfully");
        }
        return FrontResult.build("1111"."Failed to grab a red envelope!".null); }}Copy the code

• FrontResult

@Data
@AllArgsConstructor
@NoArgsConstructor
public class FrontResult implements Serializable {
    /** * Result status code */
    private String code;
    /** * Response result description */
    private String message;
    /** * returns data */
    private Object data;

    /** * static method that returns the front end entity result **@paramCode Status code *@paramMessage message *@paramThe data data *@returnFront-end entity results *@author liuBing
     */
    public static com.xiaogu.pojo.FrontResult build(String code, String message, Object data) {
        return new com.xiaogu.pojo.FrontResult(code, message, data);
    }

    /** * returns a successful result entity **@paramMessage message *@paramThe data data *@returnEntity *@author: liuBing
     * @DATE: 2020/5/25 * /
    public static com.xiaogu.pojo.FrontResult getSuccessResult(String message, Object data) {
        com.xiaogu.pojo.FrontResult result = new com.xiaogu.pojo.FrontResult();
        result.code = ResultCodeEnum.SUCCESS.code;
        result.message = message;
        result.data = data;
        return result;
    }

    /** * returns a success result entity ** without data@paramMessage Message content *@returnReturn result *@author liuBing
     */
    public static com.xiaogu.pojo.FrontResult getSuccessResultOnlyMessage(String message) {
        com.xiaogu.pojo.FrontResult result = new com.xiaogu.pojo.FrontResult();
        result.code = ResultCodeEnum.SUCCESS.code;
        result.message = message;
        result.data = "1";
        return result;
    }

    /** * get an exception result **@paramCode Indicates the error code *@paramMessage User-defined exception message *@return FrontResult
     * @authorLiu * /
    public static com.xiaogu.pojo.FrontResult getExceptionResult(String code, String message) {
        com.xiaogu.pojo.FrontResult result = new com.xiaogu.pojo.FrontResult();
        result.code = code.isEmpty() ? ResultCodeEnum.CODE_EXCEPTION.code : code;
        result.message = message.isEmpty() ? ResultCodeEnum.CODE_EXCEPTION.getMsg() : message;
        returnresult; }}Copy the code

• RedPacket

@Data
public class RedPacket implements Serializable {
    private static final long serialVersionUID = 9036484563091364939L;
    // Red envelope number
    private Long id;
    // The user id of the red envelope
    private Long userId;
    // The amount of red envelope
    private Double amount;
    // The date of the red envelope
    private Timestamp sendDate;
    // The total number of red packets
    private Integer total;
    // The amount of a single red envelope
    private Double unitAmount;
    // The number of red packets left
    private Integer stock;
    // Version (for future extensions)
    private Integer version;
    / / note
    private String note;
}
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• UserRedPacket

@Data
@Accessors(chain = true)
public class UserRedPacket implements Serializable {
    private static final long serialVersionUID = 7049215937937620886L;

    // User red envelope ID
    private Long id;
    / / a red envelope id
    private Long redPacketId;
    // The id of the user who grabbed the red envelope
    private Long userId;
    // Grab the red envelope amount
    private Double amount;
    // Grab the red envelope time
    private Timestamp grabTime;
    / / note
    private String note;
}
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• RedPacketMapper.xml

<! DOCTYPE mapper PUBLIC"- / / mybatis.org//DTD Mapper / 3.0 / EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.xiaogu.dao.RedPacketDao"> <! --> <select id="getRedPacket" parameterType="long"
            resultType="com.xiaogu.pojo.RedPacket"> select id, user_id as userId, amount, send_date as sendDate, total, unit_amount as unitAmount, stock, version, note from T_RED_PACKET where id = #{id} </select> <! --> <update id="decreaseRedPacket">
		update T_RED_PACKET set stock = stock - 1 where id =
		#{id}
	</update>


</mapper>
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• UserRedPacketMapper.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.xiaogu.dao.UserRedPacketDao"> <! --> <insert id="grapRedPacket" useGeneratedKeys="true"
            keyProperty="id" parameterType="com.xiaogu.pojo.UserRedPacket">
	    insert into
	        T_USER_RED_PACKET
	        ( red_packet_id, user_id, amount, grab_time, note)
	    values
	        (#{redPacketId}, #{userId}, #{amount}, now()#,{note})
    </insert>
</mapper>
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