pager.java

java 编写的sqlserver快速分页通用类

/**
 * <ol>
 * @author 袁  军
 * <br>Time: 2005-08-23
 * <br>Company: 湖北工业大学计算机学院
 * <br>Email:  [e-mail]
 * </ol>
 * 页面类，代表每一个页面
 * @version 1.0
 */
public class Pager {
  private   long totalRows; //总行数
  private   long pageSize = 2; //每页显示的行数
  private   long currentPage; //当前页号
  private   long totalPages; //总页数
  private   long startRow; //当前页在数据库中的起始行
  public Pager() {
  }
  public Pager(long _totalRows) {
    totalRows = _totalRows;
    totalPages=totalRows/pageSize;
    long mod=totalRows%pageSize;
    if(mod>0){
      totalPages++;
    }
     currentPage = 1;
     startRow = 0;
  }
  public long getStartRow() {
    return startRow;
  }
  public long getTotalPages() {
    return totalPages;
  }
  public long getCurrentPage() {
    return currentPage;
  }
  public long getPageSize() {
    return pageSize;
  }
  public void setTotalRows(long totalRows) {
    this.totalRows = totalRows;
  }
  public void setStartRow(long startRow) {
    this.startRow = startRow;
  }
  public  void setTotalPages(long totalPages) {
  	this.totalPages = totalPages;
  }
  public void setCurrentPage(long currentPage) {
    this.currentPage = currentPage;
  }
  public void setPageSize(long pageSize) {
    this.pageSize = pageSize;
  }
  public long getTotalRows() {
    return totalRows;
  }
  public void first() {
    currentPage = 1;
    startRow = 0;
  }
  public void previous() {
    if (currentPage == 1) {
      return;
    }
    currentPage--;
    startRow = (currentPage - 1) * pageSize;
  }
  public void next() {
    if (currentPage < totalPages) {
      currentPage++;
    }
    startRow = (currentPage - 1) * pageSize;
  }
  public void last() {
    currentPage = totalPages;
    startRow = (currentPage - 1) * pageSize;
  }
  public void refresh(long _currentPage) {
    currentPage = _currentPage;
    setStartRow((_currentPage-1)*pageSize);
    totalPages=totalRows/pageSize;
    long mod=totalRows%pageSize;
    if(mod>0){
        totalPages++;
      }
    if (currentPage > totalPages) {
      last();
    }
    if(currentPage<1){
      first();	
    }
  }  
}