dbmanager.java

使用JFREECHART组件 读取数据库数据

package cn.itcast.utils;

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

public class DBManager {
	//定位
//	String url = "jdbc:oracle:thin://127.0.0.1:1521:orcl";
//	//验证
//	String username="itcast";
//	String password = "orcl";
//	
//	static String driverName =  "oracle.jdbc.driver.OracleDriver";
	
	String url = DBConfigReader.getURL();
	String username = DBConfigReader.getUsername();
	String password = DBConfigReader.getPassword();
	
	static String driverName = DBConfigReader.getDriverName();
	
	static{
		try {
			Class.forName(driverName);
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	public Connection getConnection() {
		Connection con = null;
		
		try {
			con = DriverManager.getConnection(url,username,password);
			//System.out.println(con.getAutoCommit());
			
		} catch (SQLException e) {
			//throw new Exception("连接打不开!");
		}
		
		//System.out.println(con);
		return con;
		
	}
	
	public void freeResources(ResultSet rs,Statement stmt,Connection con){
		try {
			if( rs != null){
				rs.close();
			}
			
			if( stmt != null){
				stmt.close();
			}
			
			if(con != null){
				con.close();
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	
	public void freeResources(Statement stmt,Connection con){
		freeResources(null,stmt,con);
	}
	
	public static void main(String[]argvs){
		new DBManager().getConnection();
		
	}
	
}