opersqldaoimpl.java

开发的一个java web的任务管理系统。

package unicom.dao;

import unicom.bean.Operator;
import unicom.util.*;
import java.sql.*;


/**
 * @author xiaogang
 * 日期：Apr 16, 2008
 * 功能：实现接口IOperatorDAO,封装具体的业务操作
 * 优点：降低耦合，容易控制
 * 缺点：
 * 建议：<1>最好把sql语句写全，容易维护
 *      <2>尽量用PreparedStatement
 */
public class OperSqlDaoImpl implements IOperatorDao {

	public boolean addOperator(Operator oper) {
		//具体实现与数据库的访问，增加管理员
		boolean flag = false;
		String name = oper.getName();
		String pwd = oper.getPwd();
		String isAdmin = oper.getIsAdmin();
		String sql = "insert into toperator values(null,'" + name + "','" + pwd
				+ "','" + isAdmin + "')";
		//调用isExist(TOperator oper)判断被添加的管理员是否在数据库中存在
		if (isExist(oper)) {
			return flag;
		} else {
			Connection conn = DBUtil.getConn();
			Statement stmt = DBUtil.getStatement(conn);
			DBUtil.executeUpdate(stmt, sql);
			flag = true;
			return flag;
		}

	}

	public boolean checkOperator(Operator oper) {
		// 具体实现与数据库的访问，验证是否为合法的管理员
		boolean flag = false;
		String name = oper.getName();
		String pwd = oper.getPwd();
		String sql = "select * from toperator where name = '" + name
				+ "' and pwd = '" + pwd + "'";
		int index = 0;

		Connection conn = DBUtil.getConn();
		Statement stmt = DBUtil.getStatement(conn);
		ResultSet rs = DBUtil.getResultSet(stmt, sql);
		try {
			while (rs.next()) {
				index++;
			}
			if (index != 0) {
				flag = true;
			}
		} catch (SQLException e) {
			System.out.println(e);
		} finally {
			//释放数据库资源
			DBUtil.close(rs);
			DBUtil.close(stmt);
			DBUtil.close(conn);
		}
		return flag;
	}

	//判断是否已经存在数据库管理员
	public boolean isExist(Operator oper) {
		boolean flag = false;
		int index = 0;
		String name = oper.getName();
		String pwd = oper.getPwd();
		String isAdmin = oper.getIsAdmin();
		String sql = "select * from toperator where name = '" + name + "'";
		Connection conn = DBUtil.getConn();
		Statement stmt = DBUtil.getStatement(conn);
		ResultSet rs = DBUtil.getResultSet(stmt, sql);
		try {
			while (rs.next()) {
				index++;
			}
			if (index != 0) {
				flag = true;
			}
		} catch (SQLException e) {
			System.out.println(e);
		} finally {
			//释放数据库资源
			DBUtil.close(rs);
			DBUtil.close(stmt);
			DBUtil.close(conn);
		}
		return flag;
	}

	//验证该操作用户是否具有管理员权限
	public boolean isAdmin(Operator oper) {
		String name = oper.getName();
		String pwd = oper.getPwd();
		boolean flag = false;
		String sql = "select isAdmin from Toperator where name = '" + name + "' and pwd = '" + pwd + "'";   
		String temp = "";
		Connection conn = DBUtil.getConn();
		Statement stmt = DBUtil.getStatement(conn);
		ResultSet rs = DBUtil.getResultSet(stmt, sql);
		try {
			if(rs.next())
			{
				temp = rs.getString(1);
			}
			if(temp.equals("Y"))
				flag = true;
			else
				flag = false;
		} catch (SQLException e) {
			e.printStackTrace();
			flag = false;
		}finally{
			//释放资源
			DBUtil.close(conn);
			DBUtil.close(stmt);
			DBUtil.close(rs);
		}
		return flag;
	}

}