employeedao.java

自已个人写的一款比较好的分页java+javabean+struts标签完成的自定义分页

package cn.com.thinkbank.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import cn.com.thinkbank.bean.Employee;
import cn.com.thinkbank.bean.PageBean;
import cn.com.thinkbank.db.DBCon;

public class EmployeeDao {
	public List getAll() {
		Connection conn = DBCon.getConnection();
		List list = new ArrayList();
		String sql = "SELECT * FROM EMP";
		PreparedStatement pstmt = null;
		ResultSet rs = null;

		try {
			pstmt = conn.prepareStatement(sql);
			rs = pstmt.executeQuery();
			while (rs.next()) {
				Employee employee = new Employee();
				employee.setDeptNo(rs.getInt("deptNo"));
				employee.setEmpName(rs.getString("ename"));
				employee.setEmpNo(rs.getInt("empno"));
				list.add(employee);
			}
		} catch (SQLException e) {
			// TODO 自动生成 catch 块
			e.printStackTrace();
		}

		return list;
	}

	public List getByPage(PageBean pageBean) {
		Connection conn = DBCon.getConnection();
		List list = new ArrayList();
		String sql = " SELECT * FROM" + " (" + " SELECT A.*, rownum r"
				+ " FROM" + " (" + " SELECT *" + " FROM " + "EMP"
				+ " ORDER BY " + "empNo" + " DESC" + " ) A"
				+ " WHERE rownum <= "
				+ (pageBean.getStartResult() + pageBean.getPageSize()) + " ) B"
				+ " WHERE r > " + pageBean.getStartResult();
		PreparedStatement pstmt = null;
		ResultSet rs = null;

		try {
			pstmt = conn.prepareStatement(sql);
			rs = pstmt.executeQuery();
			while (rs.next()) {
				Employee employee = new Employee();
				employee.setDeptNo(rs.getInt("deptNo"));
				employee.setEmpName(rs.getString("ename"));
				employee.setEmpNo(rs.getInt("empno"));
				list.add(employee);
			}
		} catch (SQLException e) {
			// TODO 自动生成 catch 块
			e.printStackTrace();
		}
		return list;

	}

	public int size() {
		Connection conn = DBCon.getConnection();
		String sql = "SELECT COUNT(*) FROM EMP";
		PreparedStatement pstmt = null;
		ResultSet rs = null;
		int size = 0;
		try {
			pstmt = conn.prepareStatement(sql);
			rs = pstmt.executeQuery();
			rs.next();
			size = rs.getInt(1);
		} catch (SQLException e) {
			// TODO 自动生成 catch 块
			e.printStackTrace();
		}
		return size;
	}

	public static void main(String[] args) {
		EmployeeDao dao = new EmployeeDao();
		System.out.println(dao.getAll());
		PageBean pageBean = new PageBean(5, dao.size());
		List list = null;
		for (int i = 0; i < pageBean.getTotalPages(); i++) {
			pageBean.setCurrentPage(i + 1);
			list = dao.getByPage(pageBean);
			System.out.println("****************SIZE" + list.size());
			for (Iterator iter = list.iterator(); iter.hasNext();) {
				Employee employee = (Employee) iter.next();
				System.out.println(employee.getEmpName());
			}
		}

	}
}