JAVA　JDBC　MYSQL连接源代码

import java.io.IOException; import java.io.InputStream; import java.sql.Connection; import java.sql.Driver; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.Properties; public class JDBCDemo { public static Properties getProperties() { Properties props = new Properties(); InputStream is = null; try { is = JDBCDemo.class.getResourceAsStream("./jdbc_mysql.properties");// 按照参数路劲获得属性文件构造文件输入流 props.load(is);// 从输入流中读取属性表 } catch (Exception e1) { e1.printStackTrace(); return null; } finally { if (is != null) { try { is.close(); } catch (IOException e2) { e2.printStackTrace(); } } } return props; } public static void main(String[] args) { Statement stmt = null; ResultSet rs = null; Connection con = null; String sql = "SELECT * FROM student"; String accountId; String accountName; String accountPassword; Properties props = getProperties(); if (props != null) { String driver = props.getProperty("driver"); System.out.println(driver); String url = props.getProperty("url"); System.out.println(url); String username = props.getProperty("user"); System.out.println(username); String password = props.getProperty("password"); System.out.println(password); try { Class.forName(driver);//注册数据库驱动程序 con = DriverManager.getConnection(url, username, password);//建立到数据库库url连接 stmt = con.createStatement();//创建一个 Statement 对象来将 SQL 语句发送到数据库 rs = stmt.executeQuery(sql); //执行数据库查询并将查询结果集数据表 rs System.out.println("ID\t姓名\t密码\t"); while (rs.next()) { accountId = rs.getString(1); accountName = rs.getString(2); accountPassword = rs.getString(3); System.out.println(accountId + " \t" + accountName + " \t" + accountPassword); } } catch (Exception e3) { e3.printStackTrace(); } finally {// 释放连接 try { if (rs != null) rs.close(); if (stmt != null) stmt.close(); if (con != null) con.close(); } catch (Exception e4) { e4.printStackTrace(); } } } } }