数据库的连接程序
import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.Statement;public class DBBean {private Connection con = null;private Statement stmt;private ResultSet rs;public DBBean() {}// 得到连接public Connection getConnextion() throws Exception {// 连接数据库的urlString url = "jdbc:oracle:thin:@10.2.104.50:1521:orcl";// 用户名String dbuser = "scott";// 口令String dbpass = "a123456";if (con == null) {// 加载驱动程序，参数是驱动程序的名字Class.forName("oracle.jdbc.driver.OracleDriver");// 建立连接，第一个参数是url// 第二个参数是用户名，第三个参数是口令con = DriverManager.getConnection(url, dbuser, dbpass);}return con;}// 执行有结果集返回的sql语句public ResultSet executeQuery(String sql) throws Exception {con = getConnextion();if (con == null)throw new Exception("没有连接对象可用");// 创建语句对象stmt = con.createStatement();rs = stmt.executeQuery(sql);return rs;}// 执行更新语句public int executeUpdate(String sql) throws Exception {con = getConnextion();if (con == null)throw new Exception("没有连接可用");// 创建语句对象stmt = con.createStatement();// 执行sql语句return stmt.executeUpdate(sql);}public void close() {try {if (rs != null)rs.close();} catch (Exception e) {}try {stmt.close();} catch (Exception e) {}try {con.close();} catch (Exception e) {}}public static void main(String[] args) throws Exception {String sql = "select * from users";ResultSet rs = new DBBean().executeQuery(sql);while (rs.next()) {System.out.println(rs.getString(1));}}}