package util; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.List; /** * @author Hongyu * * @param <T> */ public class Pagination<T> { // 当前页 private Integer nowPage; // 页面要显示信息条数 private Integer pageSize; // 根据页面显示的条数计算总页数 private Integer countPage; // 根据传入的数据库查询数据库中的信息的条数 private Integer total; // 向数据库查询时的开始的下标 private Integer startIndex; // 向数据库查询时的查询条数 private Integer endIndex; // 将查询到的数据存放到这里 private List<T> rows; public Pagination(Integer nowPage, Integer pageSize, String tableName) { // 赋值 this.nowPage = nowPage; this.pageSize = pageSize; // 判断当前页是否合法 if (this.nowPage < 1) { this.nowPage = 1; } // 向数据库发送查询,查询出指定表格的数据的总数 this.total = this.getCountSize(tableName); // 计算总页数 this.countPage = this.total % this.pageSize == 0 ? this.total / this.pageSize : this.total / this.pageSize + 1; if (this.nowPage > this.countPage) { this.nowPage = this.countPage; } //System.out.println("pagenation中的nowPage==========" + this.nowPage); // 计算出开始的记录下标,和每页要显示的条数 if (this.nowPage == 0) { this.startIndex = this.nowPage * this.pageSize; this.endIndex = this.pageSize; } else { this.startIndex = (this.nowPage - 1) * this.pageSize; this.endIndex = this.pageSize; } /*System.out.println(this.startIndex + "======pagenation中的开始和结束========" + this.endIndex+"====================总页数"+countPage); */ } // 根据提供的表名向数据库发送请求,计算指定数据表中的数据总条数 public Integer getCountSize(String tableName) { int countRecord = 0; String sql = "select count(*) as c from " + tableName; Connection conn = JdbcUtil.getConn(); PreparedStatement pstmt = null; ResultSet rs = null; try { pstmt = conn.prepareStatement(sql); rs = pstmt.executeQuery(); if (rs.next()) { countRecord = rs.getInt("c"); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { JdbcUtil.release(rs, pstmt); } return countRecord; } public List<T> getRows() { return rows; } public void setRows(List<T> rows) { this.rows = rows; } public Integer getStartIndex() { return startIndex; } public Integer getEndIndex() { return endIndex; } public Integer getTotal() { return total; } }