/**
 * Oracle 数据库的连接方式实现方法
 */
public void testJDBCCommon() {
    // 建立数据库连接对象
    Connection conn = null;
    Statement st = null;
    ResultSet rst = null;
    Driver driver = null;
    try {
        //step 1： 注册驱动到jvm
        driver = new oracle.jdbc.driver.OracleDriver();
        DriverManager.registerDriver(driver);
        //step 2：获取数据库连接； 
        conn = DriverManager.getConnection(
                "jdbc:oracle:thin:@localhost:1521:XE","hr","hr");
        //step 3：创建Statement；
        st = conn.createStatement();    
        //step 4：执行查询语句，获取结果集；
        rst = st.executeQuery("select * from employees");
         //step 5：处理结果集—输出结果集中保存的查询结果； 
        while (rst.next()) {
            System.out.println(rst.getString(1) + "  " + rst.getString(2)
                    + " " + rst.getString("LAST_NAME"));
 
        }
 
    } catch (sqlException e) {
        e.printStackTrace();
    } finally {// 无论运行会不会进入到try。。catch代码块，最终都会运行finally代码块
        // 关闭对象，防止多用户环境下挂起问题和锁定问题
        try {
            if (rst != null)
                rst.close();
            if (st != null)
                st.close();
            if (conn != null)
                conn.close();
            driver = null;
        } catch (sqlException e) {
            e.printStackTrace();
        }
    }
 
}