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;
 }
}