roledao.java

一个jsp的oa系统,里面有很多亮点学习!

package com.oa.lp.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;
import java.util.List;

import com.oa.lp.model.Menu;
import com.oa.lp.model.Role;
import com.oa.lp.util.DTOPopulator;
import com.oa.lp.util.PageList;
import com.oa.lp.util.Pages;

public class RoleDAO {
	private Connection conn;
	public Connection getConn() {
		return conn;
	}

	public void setConn(Connection conn) {
		this.conn = conn;
	}
	/**
	 * 新增角色
	 * @param menu
	 * @throws SQLException
	 */
	public void addRole(Role role) throws SQLException{
		String sql = "insert into SYS_ROLE(ROLE_NAME,ROLE_DESCI,ROLE_STATE)values(?,?,?)";
		PreparedStatement pstmt = conn.prepareStatement(sql);
		pstmt.setString(1,role.getRoleName());
		pstmt.setString(2,role.getRoleDesci());
		pstmt.setInt(3,role.getRoleState());
		pstmt.executeUpdate();
		pstmt.close();
	}
	/**
	 * 更新角色
	 * 
	 */
	public void updateRole(Role role) throws SQLException{
		String sql = "update SYS_ROLE set ROLE_NAME=?,ROLE_DESCI=?,ROLE_STATE=? where ROLE_ID=?";
		PreparedStatement pstmt = conn.prepareStatement(sql);
		pstmt.setString(1,role.getRoleName());
		pstmt.setString(2,role.getRoleDesci()); 
		pstmt.setInt(3,role.getRoleState());
		pstmt.setInt(4,role.getRoleId());
		pstmt.executeUpdate();
		pstmt.close();
	}
	/**
	 * 通过ID查找
	*/
	public Role getById(int roleId) throws Exception{ 
		Role role = null;
		String sql = "select * from SYS_ROLE where ROLE_ID=?";
		PreparedStatement pstmt = conn.prepareStatement(sql);
		pstmt.setInt(1,roleId);
		ResultSet rs = pstmt.executeQuery();
		//将结果集中的每一行记录封装成一个对象,再放进集合返回
		List list = DTOPopulator.populate(rs, Role.class);
		//取集合中的第一个元素返回
		if(list.size()>0){
			role=(Role)list.get(0);
		}
		rs.close();
		pstmt.close();
		
		return role;
	}
	/**
	 * 角色分页列表
	 * @param page
	 * @return
	 * @throws Exception
	 */
	public PageList listAllRole(Pages page) throws Exception{
		PageList pageList = new PageList();
		//总录数
		page.setAllRecord(countAllRole());
		page.doPage();
		
		StringBuffer sql = new StringBuffer();
		sql.append("select * from (");
		sql.append("select top "+page.getPageSize()+" * from (");
		sql.append("select top "+(page.getPageSize()*page.getCPage())+" * from ");
		sql.append("SYS_ROLE order by ROLE_ID desc) t1 order by ROLE_ID asc) t2 order by ROLE_ID desc");
		
		PreparedStatement pstmt = conn.prepareStatement(sql.toString());
		ResultSet rs = pstmt.executeQuery();
		//将结果集中的每一行记录封装成一个对象,再放进集合返回
		List list = DTOPopulator.populate(rs, Role.class);
		
		pageList.setPage(page);
		pageList.setObjectList(list);
		pstmt.close();
		return pageList;
	}
	/**
	 * 得到所有的角色但不分页
	 * @return
	 * @throws Exception 
	 */
	public List listAllRole() throws Exception{
		List list=null;
		String sql="select *from SYS_ROLE order by ROLE_ID desc";
		PreparedStatement pstmt = conn.prepareStatement(sql.toString());
		ResultSet rs = pstmt.executeQuery();
		//将结果集中的每一行记录封装成一个对象,再放进集合返回
		list=DTOPopulator.populate(rs, Role.class);
		rs.close();
		pstmt.close();
		return list;
	}
	/**
	 * 角色总记录数
	 * @return
	 * @throws SQLException 
	 */
	public int countAllRole() throws SQLException{
		int count = 0;
		String sql = "select count(*) from SYS_ROLE";
		PreparedStatement pstmt = conn.prepareStatement(sql);
		ResultSet rs = pstmt.executeQuery(); 
		if(rs.next()){
			count = rs.getInt(1);
		}
		pstmt.close();
		return count;
	}
	/**
	 * 删除角色
	 */
	public boolean delRole(int roleId) throws SQLException{
		boolean flag=true;
		//是否给角色分配权限
		String sql = "select count(*) from SYS_ROLE_POWER where ROLE_ID=?";
		PreparedStatement pstmt = conn.prepareStatement(sql);
		pstmt.setInt(1,roleId);
		ResultSet rs = pstmt.executeQuery();
		if(rs.next()){
			if(rs.getInt(1)>0){
				flag = false;
			}
		}
		rs.close();
		pstmt.close();
		
		if(flag){
			//删除
			sql = "delete from SYS_ROLE where ROLE_ID=?";
			pstmt = conn.prepareStatement(sql);
			pstmt.setInt(1,roleId);
			pstmt.executeUpdate();
			pstmt.close();
		}
		return flag;
	}
	
}