使用mybatis 帮我实现： select username,count(1) as cnt from A s force index(pubdate) where s.pubdate between 1682870400 and 1685513781 and s.status in(2,3) and s.isessence = 0 and s.illegal_copy = 0 and ( s.sourcescore > 0 or not exists( select * from B v where v.source_id = s.id and s.sourcescore = 0 and v.can_use = 0 ) ) group by username order by cnt desc

假设你的 A 表对应的实体类是 `AEntity`，那么可以按照以下步骤实现：

1. 在 `AEntity` 中添加成员变量 `username` 和 `cnt`，并生成对应的 getter 和 setter 方法。

public class AEntity {
    private String username;
    private int cnt;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public int getCnt() {
        return cnt;
    }

    public void setCnt(int cnt) {
        this.cnt = cnt;
    }
}

2. 在 `AEntity` 的 mapper 接口中添加以下方法：

public interface AEntityMapper {
    @Select("select username, count(1) as cnt " +
            "from A s force index(pubdate) " +
            "where s.pubdate between #{start} and #{end} " +
            "and s.status in (2, 3) " +
            "and s.isessence = 0 " +
            "and s.illegal_copy = 0 " +
            "and (s.sourcescore > 0 " +
            "or not exists (select * from B v where v.source_id = s.id and s.sourcescore = 0 and v.can_use = 0)) " +
            "group by username " +
            "order by cnt desc")
    List<AEntity> selectUsernameAndCount(@Param("start") long start, @Param("end") long end);
}

在 `@Select` 注解中编写 SQL 语句，并使用 `@Param` 注解传入参数。注意这里使用了 `force index(pubdate)` 强制使用 `pubdate` 索引。

3. 在需要调用的地方调用该方法即可。

List<AEntity> result = sqlSession.getMapper(AEntityMapper.class).selectUsernameAndCount(1682870400, 1685513781);

以上是使用 MyBatis 实现该 SQL 语句的方法，希望对你有所帮助！