使用Java编程和springboot框架,连接mysql数据库（所需的三个表分别为奖品表名为a,活动表名为b,两者关联的表为c（中奖概率字段位于c表））实现下面两个功能 ：1.创建活动并关联奖品，一个活动必须关联8个奖品，总概率为100% 2.修改活动 活动名称不能重复 并更新关联奖品。给出具体程序，包括给出相应的controller层，service层，service实现类，dao层及mapper.xml文件

好的，以下是Java编写的代码示例，包括controller、service、dao和mapper.xml文件。

Controller层：

@RestController
@RequestMapping("/activity")
public class ActivityController {

    @Autowired
    private ActivityService activityService;

    @PostMapping("/create")
    public ResponseEntity createActivity(@RequestBody ActivityDto activityDto) {
        activityService.createActivity(activityDto);
        return ResponseEntity.ok("Create activity success");
    }

    @PutMapping("/update")
    public ResponseEntity updateActivity(@RequestBody ActivityDto activityDto) {
        activityService.updateActivity(activityDto);
        return ResponseEntity.ok("Update activity success");
    }
}

Service层：

public interface ActivityService {

    void createActivity(ActivityDto activityDto);

    void updateActivity(ActivityDto activityDto);
}

Service实现类：

@Service
public class ActivityServiceImpl implements ActivityService {

    @Autowired
    private ActivityMapper activityMapper;

    @Autowired
    private PrizeMapper prizeMapper;

    @Autowired
    private ActivityPrizeMapper activityPrizeMapper;

    @Override
    public void createActivity(ActivityDto activityDto) {
        // 1. 创建活动
        Activity activity = new Activity();
        activity.setName(activityDto.getName());
        activityMapper.insert(activity);

        // 2. 关联奖品
        List<PrizeDto> prizeDtos = activityDto.getPrizes();
        List<ActivityPrize> activityPrizes = new ArrayList<>();
        double totalProbability = 0;
        for (PrizeDto prizeDto : prizeDtos) {
            ActivityPrize activityPrize = new ActivityPrize();
            activityPrize.setActivityId(activity.getId());
            activityPrize.setPrizeId(prizeDto.getId());
            activityPrize.setProbability(prizeDto.getProbability());
            activityPrizes.add(activityPrize);
            totalProbability += prizeDto.getProbability();
        }

        // 3. 校验概率是否为100%
        if (totalProbability != 100) {
            throw new RuntimeException("Total probability must be 100%");
        }

        // 4. 保存关联关系
        activityPrizeMapper.batchInsert(activityPrizes);
    }

    @Override
    public void updateActivity(ActivityDto activityDto) {
        // 1. 查询活动
        Activity activity = activityMapper.selectByPrimaryKey(activityDto.getId());
        if (activity == null) {
            throw new RuntimeException("Activity not exists");
        }

        // 2. 更新活动名称
        if (!activity.getName().equals(activityDto.getName())) {
            Activity activityByName = activityMapper.selectByName(activityDto.getName());
            if (activityByName != null) {
                throw new RuntimeException("Activity name already exists");
            }
            activity.setName(activityDto.getName());
            activityMapper.updateByPrimaryKey(activity);
        }

        // 3. 更新关联奖品
        List<PrizeDto> prizeDtos = activityDto.getPrizes();
        List<ActivityPrize> activityPrizes = new ArrayList<>();
        double totalProbability = 0;
        for (PrizeDto prizeDto : prizeDtos) {
            ActivityPrize activityPrize = new ActivityPrize();
            activityPrize.setActivityId(activity.getId());
            activityPrize.setPrizeId(prizeDto.getId());
            activityPrize.setProbability(prizeDto.getProbability());
            activityPrizes.add(activityPrize);
            totalProbability += prizeDto.getProbability();
        }

        // 4. 校验概率是否为100%
        if (totalProbability != 100) {
            throw new RuntimeException("Total probability must be 100%");
        }

        // 5. 删除旧的关联关系，保存新的关联关系
        activityPrizeMapper.deleteByActivityId(activity.getId());
        activityPrizeMapper.batchInsert(activityPrizes);
    }
}

DAO层：

@Repository
public interface ActivityMapper extends BaseMapper<Activity> {

    Activity selectByName(String name);
}

@Repository
public interface PrizeMapper extends BaseMapper<Prize> {
}

@Repository
public interface ActivityPrizeMapper extends BaseMapper<ActivityPrize> {

    void deleteByActivityId(Integer activityId);

    void batchInsert(List<ActivityPrize> activityPrizes);
}

Mapper.xml文件：

<?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.example.mapper.ActivityMapper">

    <resultMap id="BaseResultMap" type="com.example.entity.Activity">
        <id column="id" jdbcType="INTEGER" property="id" />
        <result column="name" jdbcType="VARCHAR" property="name" />
    </resultMap>

    <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer">
        select id, name
        from activity
        where id = #{id,jdbcType=INTEGER}
    </select>

    <select id="selectByName" resultMap="BaseResultMap" parameterType="java.lang.String">
        select id, name
        from activity
        where name = #{name,jdbcType=VARCHAR}
    </select>

    <insert id="insert" parameterType="com.example.entity.Activity">
        insert into activity (name)
        values (#{name,jdbcType=VARCHAR})
    </insert>

    <update id="updateByPrimaryKey" parameterType="com.example.entity.Activity">
        update activity
        set name = #{name,jdbcType=VARCHAR}
        where id = #{id,jdbcType=INTEGER}
    </update>

</mapper>

<?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.example.mapper.PrizeMapper">

    <resultMap id="BaseResultMap" type="com.example.entity.Prize">
        <id column="id" jdbcType="INTEGER" property="id" />
        <result column="name" jdbcType="VARCHAR" property="name" />
    </resultMap>

    <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer">
        select id, name
        from prize
        where id = #{id,jdbcType=INTEGER}
    </select>

</mapper>

<?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.example.mapper.ActivityPrizeMapper">

    <resultMap id="BaseResultMap" type="com.example.entity.ActivityPrize">
        <result column="activity_id" jdbcType="INTEGER" property="activityId" />
        <result column="prize_id" jdbcType="INTEGER" property="prizeId" />
        <result column="probability" jdbcType="DOUBLE" property="probability" />
    </resultMap>

    <delete id="deleteByActivityId" parameterType="java.lang.Integer">
        delete from activity_prize
        where activity_id = #{activityId,jdbcType=INTEGER}
    </delete>

    <insert id="insert" parameterType="com.example.entity.ActivityPrize">
        insert into activity_prize (activity_id, prize_id, probability)
        values (#{activityId,jdbcType=INTEGER}, #{prizeId,jdbcType=INTEGER}, #{probability,jdbcType=DOUBLE})
    </insert>

    <insert id="batchInsert">
        <foreach collection="list" item="item" index="index" separator=";">
            insert into activity_prize (activity_id, prize_id, probability)
            values (#{item.activityId,jdbcType=INTEGER}, #{item.prizeId,jdbcType=INTEGER}, #{item.probability,jdbcType=DOUBLE})
        </foreach>
    </insert>

</mapper>

以上是Java编写的实现，使用了SpringBoot和MyBatis框架，其中controller层提供了两个接口，分别用于创建和更新活动，service层提供了对应的接口实现，dao层提供了数据库操作的接口，mapper.xml文件提供了对应的SQL语句。