我对分页的页面不知道怎么下手
工具类 在页面 如何使用不清楚，求高人指点
public class Pagination implements Serializable {
private static final long serialVersionUID = 1L;
private int start; // start表示当前页开始的记录数,start=每页行数*(当前页数-1)
private int end; // 当前页结束的记录行数
private int totalCount; // 总行数
private int rowsPerPage =CommodtiyConstants.ROWS_PER_PAGE ; // 每页行数，默认15
private int currentPage; // 当前页数
private int pageListSize = CommodtiyConstants.PAGE_LIST_SIZE;// 页码列表大小，默认9
private List<Integer> pageNumList = new ArrayList<Integer>();
public Pagination() {
start = 0;
end = 0;
currentPage = 1;
this.totalCount = 0;
}
public Pagination(int totalCount, int numPerPage) {
start = 0;
end = 0;
this.totalCount = totalCount;
currentPage = 1;
if (numPerPage > 0) {
rowsPerPage = numPerPage;
}
}
/**
* 执行翻页动作
*
* @param currentPage
* 要翻到的目标页码
* @return 返回翻页对象
*/
public Pagination doPagination(int currentPage) {
gotoPage(currentPage);
return this;
}
// 设置起始数
public int getStart() {
start = rowsPerPage * (currentPage - 1);
return start;
}
// 得到起始数
public void setStart(int start) {
if (start < 0) {
this.start = 0;
} else if (start >= this.totalCount) {
this.start = this.totalCount - 1;
} else {
this.start = start;
}
}
// 设置当前页的最后一行的在总记录中的顺序(从0开始)
public void setEnd(int end) {
this.end = end;
}
// 得到当前页的最后一行的在总记录中的顺序(从0开始)
public int getEnd() {
if (rowsPerPage * currentPage > this.totalCount) {
end = this.totalCount - 1;
} else {
end = rowsPerPage * currentPage - 1;
}
return end;
}
// 以下4个方法供控制器(struts)调用
// 判断能否到第一页;只要能到上一页，肯定就有第一页
public boolean firstEnable() {
return previousEnable();
}
// 判断能否到上一页
public boolean previousEnable() {
return currentPage > 1;// 只要不是第一页，就能到上一页
}
// 判断能否到下一页
public boolean nextEnable() {
return currentPage * rowsPerPage < this.totalCount;
}
// 判断能否到最后一页；只要有下一页，就肯定有最后一页.
public boolean lastEnable() {
return nextEnable();
}
// 跳到第一页
public void firstPage() {
currentPage = 1;
}
// 跳到上一页
public void previousPage(int cPage) {
currentPage = (cPage - 1) > 0 ? (cPage - 1) : 1;
}
// 跳到下一页
public void nextPage(int cPage) {
currentPage = cPage + 1;
if (currentPage * rowsPerPage > this.totalCount) {
lastPage();
}
}
// 跳到最后一页
public void lastPage() {
if (this.totalCount % rowsPerPage == 0) {
currentPage = this.totalCount / rowsPerPage;
} else {
currentPage = this.totalCount / rowsPerPage + 1;
}
}
// 跳到指定的某一页
public void gotoPage(int pageNumber) {
if (pageNumber <= 1) {
currentPage = 1;
} else if (getTotalCount() < this.getRowsPerPage()) {
currentPage = 1;
} else if (pageNumber * rowsPerPage >= this.totalCount) {
lastPage();
} else {
currentPage = pageNumber;
}
}
// 设置总行数
public void setTotalCount(int totalCount) {
this.totalCount = totalCount;
}
// 得到总行数
public int getTotalCount() {
return totalCount;
}
// 设置每页行数
public void setRowsPerPage(int rowsPerPage) {
this.rowsPerPage = rowsPerPage;
}
// 得到每页行数
public int getRowsPerPage() {
return rowsPerPage;
}
// 得到总页数
public int getPages() {
if (this.totalCount % rowsPerPage == 0)
return this.totalCount / rowsPerPage;
else
return this.totalCount / rowsPerPage + 1;
}
// 得到当前页数
public int getCurrentPage() {
return currentPage;
}
// 设置当前页数
public void setCurrentPage(int currentPage) {
this.currentPage = currentPage;
}
public int getPageListSize() {
return pageListSize;
}
// 设置页码列表大小
public void setPageListSize(int pageListSize) {
this.pageListSize = pageListSize;
}
// 得到页面列表
public List<Integer> getPageNumList() {
this.pageNumList.removeAll(this.pageNumList);// 设置之前先清空
int totalPage = getPages();
if (totalPage > this.pageListSize) {
int halfSize = this.pageListSize / 2;
int first = 1;
int end = 1;
if (this.currentPage - halfSize < 1) { // 当前页靠近最小数1
first = 1;
end = this.pageListSize;
} else if (totalPage - this.currentPage < halfSize) { // 当前页靠近最大数
first = totalPage - this.pageListSize + 1;
end = totalPage;
} else {
first = this.currentPage - halfSize;
end = this.currentPage + halfSize;
}
for (int i = first; i <= end; i++) {
this.pageNumList.add(i);
}
} else {
for (int i = 0; i < totalPage; i++) {
this.pageNumList.add(i + 1);
}
}
return pageNumList;
}
}
