Oracle分页显示

package com.basicSql.scroll_page;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import com.basicSql.connUtil.Conndb;

/**
 * 数据库的分页显示
 * 
 * @author xrhou
 * 
 */
public class PageSplit {

	private static Connection conn = null;
	private static Statement stmt = null;
	private static PreparedStatement pStmt = null;
	private static ResultSet rs=null;

	public static void main(String[] args) {
		getPage(10, 1);
		System.out.println("========================");
		getPageSimple(10,-4);
	}

	/**
	 * 取得表的总行数
	 * @return
	 */
	public static int getTotalNumber(){
		int n=-1;
		String sql="select count(*) num from t_student ";
		try {
			conn=Conndb.connOracle();
			stmt=conn.createStatement();
			rs=stmt.executeQuery(sql);
			rs.next();
			n=rs.getInt("num");
			
		} catch (SQLException e) {
			e.printStackTrace();
		}
		//System.out.println(n);
		return n;
	}
	
	public static void getPageSimple(int pageSize, int page) {
		// totalPage:总页数 totalNumber:总记录条数
		int totalPage = 0;
		int totalNumber = getTotalNumber();

		if (totalNumber % pageSize == 0) {
			totalPage = totalNumber / pageSize;
		} else {
			totalPage = totalNumber / pageSize + 1;
		}
		if (page > totalPage) {
			page = totalPage;
		}
		if (page < 1) {
			page = 1;
		}
		
		int from=(page-1)*pageSize+1;
		int to=from+pageSize;
		getResult(from, to);
		
	}
	/**
	 * 分页
	 * 
	 * @param pageSize
	 * @param page
	 */
	public static void getPage(int pageSize, int page) {
		int from =(page-1)*pageSize+1;
		int to=from+pageSize;
		String sql = "select  id,name,age,rn "
				+ " from (select id,name,age,rownum rn from t_student "
				+ "where rownum<?) "
				+ "where rn>=?";
		try {
			conn = Conndb.connOracle();
			pStmt = conn.prepareStatement(sql);
			pStmt.setInt(1, to);
			pStmt.setInt(2, from);
			rs = pStmt.executeQuery();
			while (rs.next()) {
				String line = rs.getInt("id") + "---" + rs.getString("name")
						+ "---" + rs.getInt("age")+"---"+rs.getInt("rn");
				System.out.println(line);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}finally{
			Conndb.rsClose(rs);
			Conndb.pStmtClose(pStmt);
			Conndb.closeConn(conn);
		}
	}

	/**
	 * 分条
	 * 
	 * @param m
	 * @param n
	 */
	public static void getResult(int m, int n) {
		String sql = "select  id,name,age,rn "
				+ " from (select id,name,age,rownum rn from t_student "
				+ "where rownum<?) "
				+ "where rn>=?";
		try {
			conn = Conndb.connOracle();
			pStmt = conn.prepareStatement(sql);
			pStmt.setInt(1, n);
			pStmt.setInt(2, m);
			ResultSet rs = pStmt.executeQuery();

			while (rs.next()) {
				String line = rs.getInt("id") + "---" + rs.getString("name")
						+ "--" + rs.getDouble("age")+"--"+rs.getInt("rn");
				System.out.println(line);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

}