List<User> userList=userMapper.selectList(
        new QueryWrapper<User>()
        .lambda()
        .ge(User::getAge,18)
        );

List<User> userList = this.userService.list(
    new QueryWrapper<User>()
            .lambda()
            .ge(User::getAge, 18)
            .likeLeft(User::getName, "ext")
            .eq(User::getEmail, "[email protected]")
            ...
);

/**
 * XxxQuery
 *
 * @author WcJun
 * @date 2019/05/13
 * {@link com.photowey.copycat.criteria.query.AbstractQuery}
 */
@Data
@Accessors(chain = true)
@NoArgsConstructor
@AllArgsConstructor
public class XxxQuery extends AbstractQuery<User> implements Serializable {

    private static final long serialVersionUID = -4887537311252782223L;

    /**
     * 用户标识
     * 自动给 QueryWrapper 添加如下的语句:
     * queryWrapper.eq(null != value, columnName, value);
     */
    @Eq(alias = "id")
    private Long userId;
}

/**
 * 抽象查询对象
 *
 * @author WcJun
 * @date 2019/05/12
 */
public abstract class AbstractQuery<T> extends PaginationQuery {

    // WRAPPER

    /**
     * 通过注解自动包装查询 Wrapper
     *
     * @return
     * @see {@link com.baomidou.mybatisplus.core.conditions.query.QueryWrapper}
     */
    public QueryWrapper<T> autoWrapper() {
        return CriteriaAnnotationProcessorAdvisor.advise(this, new QueryWrapper<T>());
    }

    // PAGE

    /**
     * 如果需要分页的话
     * 获取分页对象
     *
     * @return IPage
     * @see {@link com.baomidou.mybatisplus.core.metadata.IPage}
     */
    public IPage populatePage() {
        return new Page(this.pageNo, this.pageSize);
    }
}

/**
 * 分页参数
 *
 * @author WcJun
 * @date 2019/05/12
 */
public abstract class PaginationQuery {

    /**
     * 当前页(从自然页 1 开始)
     */
    protected Integer pageNo = 1;
    /**
     * 每页展示数量 默认 20
     */
    protected Integer pageSize = 20;

    // ================================================

    public Integer getPageNo() {

        if (null != pageNo && pageNo < 1) {
            return 1;
        }

        return null == pageNo ? 1 : pageNo;
    }

    public Integer getPageSize() {

        if (null != pageSize && pageSize < 1) {
            return 1;
        }

        return null == pageSize ? 10 : pageSize;
    }

    public void setPageNo(Integer pageNo) {
        this.pageNo = pageNo;
    }

    public void setPageSize(Integer pageSize) {
        this.pageSize = pageSize;
    }
}

/**
 * 测试 @Eq
 * {@link com.photowey.copycat.criteria.annotaion.Eq}
 */
@Test
public void testQueryByEq() {
    UserQuery userQuery = new UserQuery().setUserId(1L);
    User user = this.userService.getOne(userQuery.autoWrapper());
    Assert.assertEquals("查询错误", "Jone", user.getName());
}

/**
 * 测试 Timestamp
 * {@link com.photowey.copycat.criteria.annotaion.Timestamp}
 * {@link java.time.LocalDateTime}
 * ==>  Preparing: SELECT id,name,age,email,birth_day FROM user WHERE (age >= ? AND birth_day > ?) ORDER BY age DESC
 * ==> Parameters: 20(Integer), 2019-05-11T10:00(LocalDateTime)
 *
 * @since 1.1.0
 */
@Test
public void testQueryByTimestampGe() throws ParseException {
    String birthDayStr = "2019-05-12 10:00:00";
    SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    Date birthDay = format.parse(birthDayStr);
    // 模拟前端传参
    UserQuery userQuery = new UserQuery().setAge(20).setBirthDayGe(birthDay);
    
    List<User> users = this.userService.list(userQuery.autoWrapper());
    Assert.assertEquals(3, users.size());
    users.forEach(System.out::println);
}

/**
 * 测试 Timestamp
 * {@link com.photowey.copycat.criteria.annotaion.Timestamp}
 * {@link java.time.LocalDate}
 * ==>  Preparing: SELECT id,name,age,email,birth_day FROM user WHERE (age >= ? AND birth_day > ?) ORDER BY age DESC
 * ==> Parameters: 20(Integer), 2019-05-11(LocalDate)
 *
 * @since 1.2.0
 */
@Test
public void testQueryByCriteriaTimestampByLocalDate() {
    UserQuery userQuery = new UserQuery().setAge(20).setBirthDayTimestampLocalDate(1557540000000L);
    List<User> users = this.userService.list(userQuery.autoWrapper());
    users.forEach(System.out::println);
}

/**
 * 测试 Timestamp
 * {@link com.photowey.copycat.criteria.annotaion.Timestamp}
 * {@link java.time.LocalTime}
 * ==>  Preparing: SELECT id,name,age,email,birth_day FROM user WHERE (age >= ? AND birth_day > ?) ORDER BY age DESC
 * ==> Parameters: 20(Integer), 10:00(LocalTime)
 *
 * @since 1.2.0
 */
@Test
public void testQueryByCriteriaTimestampByLocalTime() {
    UserQuery userQuery = new UserQuery().setAge(20).setBirthDayTimestampLocalTime(1557540000000L);
    List<User> users = this.userService.list(userQuery.autoWrapper());
    users.forEach(System.out::println);
}

/**
 * 测试 Timestamp
 * {@link com.photowey.copycat.criteria.annotaion.Timestamp}
 * {@link java.time.ZonedDateTime}
 * ==>  Preparing: SELECT id,name,age,email,birth_day FROM user WHERE (age >= ? AND birth_day > ?) ORDER BY age DESC
 * ==> Parameters: 20(Integer), 2019-05-11T10:00+08:00[Asia/Shanghai](ZonedDateTime)
 *
 * @since 1.2.0
 */
@Test
public void testQueryByCriteriaTimestampByZonedDateTime() {
    UserQuery userQuery = new UserQuery().setAge(20).setBirthDayTimestampZonedDateTime(1557540000000L);
    List<User> users = this.userService.list(userQuery.autoWrapper());
    users.forEach(System.out::println);
}