1、以下数据库连接及操作实例

package properties;import java.io.FileWriter;import java.io.IOException;import java.io.InputStream;import java.net.URL;import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import java.util.Properties;public class test {public static void main(String[] args) {	/*FileWriter fw;		fw = new FileWriter("tt.txt",true);//加上 true参数，代表是往这个文件中添加 内容，不是覆盖原文件的内容		fw.write("this is my");		fw.write("stu");		fw.write("dent");		fw.write(".");		fw.write("txt");		fw.write("这是我的文件");		fw.close();*/	/*URL aurl=new URL("http://www.googel.com:80");	System.out.println("protocol="+aurl.getProtocol());	System.out.println("Authority="+aurl.getAuthority());	System.out.println("Host="+aurl.getHost());	System.out.println("Port="+aurl.getPort());*/	add_update_del("update t_Accepted_Cert_Info t set t.custname='颜丽' where t.mobileno ='13536703748'");	query("select * from t_Accepted_Cert_Info info where info.mobileno ='13536703748'");}public static Properties getProperties() {	Properties prop = new Properties();//Properties 类表示了一个持久的属性集。Properties 可保存在流中或从流中加载。属性列表中每个键及其对应值都是一个字符串	try {		// /加载属性列表		//InputStream in = new BufferedInputStream(new FileInputStream(				//"D:\\myselenium\\config.properties"));		//读取当前工程下的配置文件		  InputStream in =test.class.getResourceAsStream("/properties/config.properties");// getResourceAsStream查找具有给定名称的资源,返回一个InputStream对象		prop.load(in);//从流中加载		return prop;	} catch (Exception e) {		e.printStackTrace();		return null;	}	}public static Connection getConnection(){	Connection conn=null;	String driverName=getProperties().getProperty("orcal.driverName");	String url=getProperties().getProperty("PA18dburl");	String username=getProperties().getProperty("PA18dbuser");	String pwd=getProperties().getProperty("PA18sdbpsw");	try {		Class.forName(driverName);		conn=DriverManager.getConnection(url,username,pwd);				if (conn!=null){			System.out.println("数据库连接成功");					}		return conn;	} catch (Exception e) {		// TODO Auto-generated catch block		e.printStackTrace();		return null;	}	}public static void add_update_del(String sql){	Connection conn=getConnection();		int x;	try {		Statement st=conn.createStatement();		x = st.executeUpdate(sql);		System.out.println("操作成功"+x);	} catch (SQLException e) {		// TODO Auto-generated catch block		e.printStackTrace();	}	}public static void query(String sql){	try{		Connection conn=getConnection();		Statement st=conn.createStatement();		ResultSet rs=st.executeQuery(sql);		//当返回的结果集不为空时，并且还有记录时		while(rs!=null && rs.next()){			int id=rs.getInt(1);//获取当前记录的第一个字段的值			String name=rs.getString("custname");			String addr=rs.getString("addr");			System.out.println("id"+id+"\t"+"name"+name+"\t"+"addr"+addr+"\t");					}		}catch(Exception e){			e.printStackTrace();	}		}}