java分页算法，传入当前pageIndex，pageSise，dataTotal可计算出页面上显示的页码，和是否启动上一页下一页

public class CalculationPage { 

    private Boolean showStartPagerDot;
    private Boolean showEndPagerDot;
    private int pageIndex;
    private int pageSise;
    private int totalPages;
    private int dataTotal;
    private List<Long> pageNumbers;
    private int prevPage;
    private int nextPage;

    public CalculationPage(int pageIndex, int pageSise, int dataTotal) {

        this.pageIndex = pageIndex;
        this.pageSise = pageSise;
        this.dataTotal = dataTotal;

        double dDataTotal = (double) this.dataTotal;
        double dPageSize = (double) this.pageSise;

        this.totalPages = (int) Math.ceil((dDataTotal / dPageSize));
        this.pageNumbers = new ArrayList<>();
        int start = 1;
        int pagerCount = 8;
        int end = pagerCount;
        if (this.pageIndex >= pagerCount) {
            start = this.pageIndex - pagerCount / 2;
            this.showStartPagerDot = false;
        } else {

            prevPage = this.pageIndex - 1;
            if (prevPage <= 0) {
                this.showStartPagerDot = false;
            } else {
                this.showStartPagerDot = true;
            }
        }
        end = start + pagerCount - 1;
        if (end > this.totalPages) {
            end = this.totalPages;
            if (pageIndex == end) {
                this.showEndPagerDot = false;
            } else {
                this.showEndPagerDot = true;
                this.nextPage = pageIndex + 1;
            }

        } else {
            this.nextPage = end + 1;
            if (this.nextPage >= this.totalPages) {

                this.showEndPagerDot = false;
            } else {
                this.showEndPagerDot = true;
            }

        }
        for (int i = start; i <= end; i++) {
            this.pageNumbers.add((long) i);
        }
        ;

    }

    public Boolean getShowStartPagerDot() {
        return showStartPagerDot;
    }

    public void setShowStartPagerDot(Boolean showStartPagerDot) {
        this.showStartPagerDot = showStartPagerDot;
    }

    public Boolean getShowEndPagerDot() {
        return showEndPagerDot;
    }

    public void setShowEndPagerDot(Boolean showEndPagerDot) {
        this.showEndPagerDot = showEndPagerDot;
    }

    public int getPageIndex() {
        return pageIndex;
    }

    public void setPageIndex(int pageIndex) {
        this.pageIndex = pageIndex;
    }

    public int getPageSise() {
        return pageSise;
    }

    public void setPageSise(int pageSise) {
        this.pageSise = pageSise;
    }

    public int getTotalPages() {
        return totalPages;
    }

    public void setTotalPages(int totalPages) {
        this.totalPages = totalPages;
    }

    public int getDataTotal() {
        return dataTotal;
    }

    public void setDataTotal(int dataTotal) {
        this.dataTotal = dataTotal;
    }

    public void setPageNumbers(List<Long> pageNumbers) {
        this.pageNumbers = pageNumbers;
    }

    public List<Long> getPageNumbers() {
        return pageNumbers;
    }

    public int getPrevPage() {
        return prevPage;
    }

    public void setPrevPage(int prevPage) {
        this.prevPage = prevPage;
    }

    public int getNextPage() {
        return nextPage;
    }

    public void setNextPage(int nextPage) {
        this.nextPage = nextPage;
    }
}