public PageResult findByList(@RequestBody UserDTO userDTO) {
    // 分页
    IPage<User> page = new Page(UserDTO.getPageNumber(), UserDTO.getPageSize());
    // 条件构造器
    QueryWrapper queryWrapper = new QueryWrapper();
    queryWrapper.eq("user_name", userDTO.getUserName);
    // 查询符合条件的内容
    IPage<User> pageResult = service.page(page, queryWrapper);
    // 获取符合条件的List集合
    List<User> records = pageResult.getRecords();
    System.out.println("查询结果 = " + records);
    // 返回结果
    return new PageResult(new Long(pageResult.getTotal()).intValue(), pageResult.getRecords());
}

/**
 * 分页处理
 */
@ApiModel("分页响应类")
public class PageResult<T> {
    @ApiModelProperty(value ="响应代码")
    private int code;
    @ApiModelProperty(value ="提示信息")
    private String msg;
    @ApiModelProperty(value ="总记录数")
    private int count;
    @ApiModelProperty(value ="查询到的结果集")
    private List<T> data;
    /**
     * 默认构造方法
     */
    public PageResult() {
    }
    public PageResult(int total, List<T> rows) {
        this.count = total;
        this.data = rows;
        this.code = 200;
        this.msg = Constant.ResponseMsg.OPERATE_SUCCESS;
    }
    public int getCode() {
        return code;
    }
    public void setCode(int code) {
        this.code = code;
    }
    public String getMsg() {
        return msg;
    }
    public void setMsg(String msg) {
        this.msg = msg;
    }
    public int getCount() {
        return count;
    }
    public void setCount(int count) {
        this.count = count;
    }
    public List<T> getData() {
        return data;
    }
    public void setData(List<T> data) {
        this.data = data;
    }
}