dao.java

distrubit account system for bank,

package Database;
import java.sql.*;
import java.io.*;
/**
 *@author 黄素鹏
 */
public class DAO {
	protected final String driver = "sun.jdbc.odbc.JdbcOdbcDriver";
	protected final String url = "jdbc:odbc:driver={Microsoft Access Driver (*.mdb)}" +
    		";DBQ=Banking.mdb";
	protected Connection connection;
	protected Statement statement;
	protected SQLWarning warn;
	/**
	 *定义一个构造方法
	 */
	public DAO() throws SQLException{
		try {
			Class.forName(driver);

		} catch (ClassNotFoundException e) {
			System.out.println("没有发现驱动程序:" + driver);
			e.printStackTrace();
			System.exit(1);
		}
		connection = DriverManager.getConnection(url, "", "");
		warn = connection.getWarnings();
		while(warn != null) {
			System.out.println(warn.getMessage());
			warn = warn.getNextWarning();
		}

		statement = connection.createStatement();

	}
	/**
	 *@param sql 执行参数为sql的查询语句
	 *@return 返回查询的结果集
	 */
	public ResultSet query(String sql){
		ResultSet rs = null;
		try {
			rs = statement.executeQuery(sql);
		} catch (SQLException e) {
			System.out.print("查询出错!" + e.getMessage());
			e.printStackTrace();
		}
		return rs;
	}
	/**
	 *@param sql 执行参数为sql的更新语句
	 */
	public void update(String sql) {
		try {
			statement.executeUpdate(sql);
		} catch (SQLException e) {
			System.out.println("更新出错!");
			e.printStackTrace();
		}
	}
	/**
	 *@param sql 执行参数为sql的添加语句
	 */
	public void add(String sql) {
		try {
			statement.executeUpdate(sql);
		} catch (SQLException e) {
			System.out.print("增加出错!");
			e.printStackTrace();
		}
	}
	/**
	 *@param sql 执行参数为sql的删除语句
	 */
	public void delete(String sql) {
		try {
			statement.executeUpdate(sql);
		} catch (SQLException e) {
			System.out.println("删除出错!");
			e.printStackTrace();
		}
	}
	/**
	 * 断开数据库连接
	 */
	public void disconnection(){
		try {
	         connection.close();
	      } catch (SQLException sqle) {
	         System.err.println("无法关闭数据库连接" + sqle.getMessage());
	      }
	}
 }