分页查询

1.BaseAction

    // 默认每页显示条数
    protected static final Integer DEFUALT_ROWS = 10;
    // 默认显示第几页
    protected static final Integer DEFUALT_PAGE = 1;
    private Integer rows;// 每页显示的记录数
    private Integer page;// 当前第几页

　 public Integer getPage() {
        if (this.page == null) {
            this.page = DEFUALT_PAGE;
        }
        return page;
    }

    public Integer getRows() {
        if (this.rows == null) {
            this.rows = DEFUALT_ROWS;
        }
        return rows;
    }

这两个方法在调用action层调用分页查询时调用

this.buserPage = this.buserAdminService.getBusersByCondition(buserId, buserName, super.getPage(), super.getRows(), true);

　　 @Override
    public ReturnDataListWithPage<MvBuser> getBusersByCondition(Long buserId, String bUserName, int currentPage, int onePageSize, boolean isNeedTotal) {
        ReturnDataListWithPage<MvBuser> returnData = new ReturnDataListWithPage<MvBuser>(currentPage, onePageSize);
        if (currentPage < 1 || onePageSize < 1) {
            returnData.setReturnCode(ReturnCode.EX_PARAM.getCode());
            return returnData;
        }
        try {
            if (isNeedTotal) {
                int count = dao.getBusersByConditionCount(buserId, bUserName);
                returnData.setTotalResults(count);
            }

            int startRow = returnData.getFirstResult();
            List<MvBuser> result = dao.getBusersByCondition(buserId, bUserName, startRow, onePageSize);
            returnData.setResultData(result);
            returnData.setReturnCode(ReturnCode.PASS_OK.getCode());
        } catch (Exception e) {
            log.error("MvBuserServiceImpl exception:get busers by page failed ", e);
            returnData.setReturnCode(ReturnCode.EX_UNKNOWN.getCode());
        }

在returnData对象的构造方法中初始化 查询开始条数，通过get方法获得其值

    public ReturnDataListWithPage(int currentPage, int onePageSize) {
        if (currentPage > 1)
            this.currentPage = currentPage;
        else
            this.currentPage = 1;
        this.onePageSize = onePageSize;
        this.firstResult = (this.currentPage - 1) * this.onePageSize;
    }

<select id="getBusersByConditionCount" resultType="int">
        SELECT COUNT(*) FROM mv_buser
        WHERE  1 = 1
        <if test="buser_id != null">AND  buser_id = #{buser_id} </if>
        <if test="user_name != null "> AND user_name LIKE CONCAT(CONCAT('%', #{user_name}),'%')</if>
    </select>
    
    <select id="getBusersByCondition" resultType="mvBuser">
        SELECT * FROM mv_buser
        WHERE  1 = 1
        <if test="buser_id != null">AND  buser_id = #{buser_id} </if>
        <if test="user_name != null "> AND user_name LIKE CONCAT(CONCAT('%', #{user_name}),'%')</if>
        ORDER BY buser_id
        LIMIT #{startRow}, #{onePageSize}
    </select>