2010.03.15——jdbc的使用

2010.03.15——jdbc的使用
今天 要写批量数据的导出 要用到了jdbc，就熟悉了一下

1. jdbc 六个步骤

1)注册Driver
     2)获得连接
     3)创建Statement
     4)执行sql
     5)select--->处理结果集
     6)释放资源(rs,stm,conn)

2.一个jdbcutil

public class JdbcUtil {
	private static Properties info=new Properties();
	static{	
		try {
			InputStream is=JdbcUtil.class
			   .getResourceAsStream("config/config.properties");
			info.load(is);
			is.close();
		} catch (Exception e) {
			throw  new ExceptionInInitializerError(e);
		}
	}

	private static final ThreadLocal<Connection> tl=new ThreadLocal<Connection>();
    public static Connection  getConnection() throws Exception{
    	Connection conn=tl.get();
    	if(conn==null){
    		Class.forName(info.getProperty("driver"));
    		conn=DriverManager.getConnection(info.getProperty("url"),
        			info.getProperty("username"),info.getProperty("password"));
    		tl.set(conn);
    	}
    	return conn;
    }
	public static void release(ResultSet rs,Statement stm,Connection conn){
		if(rs!=null)  try{ rs.close();} catch(Exception ee){}
		if(stm!=null)  try{ stm.close();} catch(Exception ee){}
		if(conn!=null) try{ conn.close();} catch(Exception ee){}
	}
	public static void main(String[] args) throws Exception{
		System.out.println(getConnection());
	}
}

config.properties

driver=oracle.jdbc.driver.OracleDriver
url=jdbc:oracle:thin:@localhost:1521:orcl
username=system
password=cody