java 分页

public class Pager {

	private int currentPage = 1;// 当前页
	private int totalPages = 0;// 总页数
	private int showPages = 10;// 分页要显示的页数
	private int pageRecorders = 2;// 每页记录
	private int totalRows = 0;// 总行数
	private int pageStartRow = 0;// 每页的起始行
	private int pageEndRow = 0;// 每页显示的终止数
	private boolean hasNextPage = false;// 没有下一页
	private boolean hasPreviousPage = false;// 没有上一页

	private List list;// 传过一个list，就可以对list进行分页
	private String url;// action跳转页面

	public void ShowByPageImpl(List list, String url) {
		this.list = list;
		this.url = url;
		totalRows = list.size();
		hasPreviousPage = false;
		currentPage = 1;
		if (totalRows % pageRecorders == 0) {
			totalPages = totalRows / pageRecorders;
		} else {
			totalPages = totalRows / pageRecorders + 1;
		}
		if (currentPage >= totalPages) {
			hasNextPage = false;
		} else {
			hasNextPage = true;
		}
		if (totalRows < pageRecorders) {
			this.pageStartRow = 0;
			this.pageEndRow = totalRows;
		} else {
			this.pageStartRow = 0;
			this.pageEndRow = pageRecorders;
		}
	}

	public int getCurrentPage() {
		return currentPage;
	}

	public void setCurrentPage(int currentPage) {
		this.currentPage = currentPage;
	}

	public int getTotalPages() {
		return totalPages;
	}

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

	public int getPageRecorders() {
		return pageRecorders;
	}

	public void setPageRecorders(int pageRecorders) {
		this.pageRecorders = pageRecorders;
	}

	public int getTotalRows() {
		return totalRows;
	}

	public void setTotalRows(int totalRows) {
		this.totalRows = totalRows;
	}

	public int getPageStartRow() {
		return pageStartRow;
	}

	public void setPageStartRow(int pageStartRow) {
		this.pageStartRow = pageStartRow;
	}

	public int getPageEndRow() {
		return pageEndRow;
	}

	public void setPageEndRow(int pageEndRow) {
		this.pageEndRow = pageEndRow;
	}

	public boolean isHasNextPage() {
		return hasNextPage;
	}

	public void setHasNextPage(boolean hasNextPage) {
		this.hasNextPage = hasNextPage;
	}

	public boolean isHasPreviousPage() {
		return hasPreviousPage;
	}

	public void setHasPreviousPage(boolean hasPreviousPage) {
		this.hasPreviousPage = hasPreviousPage;
	}

	public List getList() {
		return list;
	}

	public void setList(List list) {
		this.list = list;
	}

	// 首页
	public void getFirstPage() {
		currentPage = 1;
		hasPreviousPage = false;
		if (currentPage >= totalPages) {
			hasNextPage = false;
		} else {
			hasNextPage = true;
		}
	}

	// 下一页
	public void getNextPage() {
		currentPage = currentPage + 1;
		if ((currentPage - 1) > 0) {
			hasPreviousPage = true;
		} else {
			hasPreviousPage = false;
		}
		if (currentPage >= totalPages) {
			hasNextPage = false;
		} else {
			hasNextPage = true;
		}
	}

	// 上一页
	public void getPreviousPage() {
		currentPage = currentPage - 1;
		if (currentPage == 0) {
			currentPage = 1;
		}
		if (currentPage >= totalPages) {
			hasNextPage = false;
		} else {
			hasNextPage = true;
		}
		if ((currentPage - 1) > 0) {
			hasPreviousPage = true;
		} else {
			hasPreviousPage = false;
		}
	}

	// 最后一页
	public void getLastPage() {
		currentPage = totalPages;
		if (currentPage == 0) {
			currentPage = 1;
		}
		hasNextPage = false;
		if ((currentPage - 1) > 0) {
			hasPreviousPage = true;
		} else {
			hasPreviousPage = false;
		}
	}

	// 获取选择页
	public void getSelectPage(int selectPage) {
		currentPage = selectPage;
		if (currentPage >= totalPages)
			hasNextPage = false;
		else
			hasNextPage = true;
		if ((currentPage - 1) > 0)
			hasPreviousPage = true;
		else
			hasPreviousPage = false;
	}

	// 获取当前列表
	public List getPageList() {
		if (currentPage * pageRecorders < totalRows) {
			pageEndRow = currentPage * pageRecorders;
			pageStartRow = pageEndRow - pageRecorders;
		} else {
			pageEndRow = totalRows;
			pageStartRow = pageRecorders * (totalPages - 1);
		}
		List templist = new ArrayList();
		for (int j = 0, i = pageStartRow; i < pageEndRow; j++, i++)
			templist.add(j, list.get(i));
		return templist;
	}

	// 控制页面跳转
	public void controlPage(String action) {
		if (action.equals("firstPage"))
			this.getFirstPage();
		else if (action.equals("nextPage"))
			this.getNextPage();
		else if (action.equals("previousPage"))
			this.getPreviousPage();
		else if (action.equals("lastPage"))
			this.getLastPage();
		else
			this.getSelectPage(Integer.valueOf(action));
	}
}

action中调用：

Pager pager = new Pager();
		int currentPage = Integer.parseInt(request.getParameter("currentPage"));//客户端当前显示的页数
		int contentNum = Integer.parseInt(request.getParameter("contentNum"));//每页显示的内容条数
		pager.ShowByPageImpl(productList, currentPage, contentNum);//分页处理
		List listPage = pager.getPageList(currentPage, contentNum, productList.size());//获取当前列表
		int totalPage = pager.getTotalPages();//获得总页数