db.java

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/**
 *  封装了数据库相关操作的类
 *  DB.java
*/

package building;

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

import javax.sql.DataSource;

public class DB
{
	Connection connect = null;
	ResultSet rs = null;
	
	//利用构造方法建立与数据库的连接
	public DB(DataSource dataSource)
	{
		try
		{
			System.out.println("db" + dataSource);
			connect = dataSource.getConnection();
		}
		catch (SQLException ex)
		{
			ex.printStackTrace();
		}
		
	}//End of DB
	
	/**
	 * 在数据库中执行数据查询方法
	 */
	public ResultSet OpenSql(String sql)
	{
		try
		{
			Statement stmt = connect.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
					ResultSet.CONCUR_READ_ONLY);
			rs = stmt.executeQuery(sql);
		}
		catch (SQLException ex)
		{
			ex.printStackTrace();
		}
		
		return(rs);
	}//End of OpenSql
	
	/**
	 * 在数据库中执行数据更新的方法
	 */
	public int ExecSql(String sql)
	{
		int result = 0; //result为0则为失败
		try
		{
			Statement stmt = connect.createStatement();
			result = stmt.executeUpdate(sql);
		}
		catch (SQLException ex)
		{
			System.out.println(ex.getMessage());
		}
		
		return(result);
	}//End of ExecSql
	
	/**
	 * 关闭与数据库连接的方法
	 */
	public void close()
	{
		if (connect != null)
		{
			try
			{
				connect.close();
				connect = null;
			}
			catch (SQLException ex)
			{
				System.err.println(ex.getMessage());
			}
		}//End of if
		
	}//End of close
	
}//End of class DB