public static void main(String[] args) {        try {            Class.forName("oracle.jdbc.OracleDriver");            Connection con = DriverManager.getConnection("jdbc:Oracle:thin:DEVH3IMAGE/oracle@//localhost:1521/orcl");                        //获取数据库元信息            DatabaseMetaData data =http://www.mamicode.com/ con.getMetaData();            System.out.println("数据库db名称："+data.getDatabaseProductName());            System.out.println("数据库db版本"+data.getDatabaseProductVersion());            System.out.println("链接驱动名称："+data.getDriverName());            System.out.println("db链接url信息："+data.getURL());                        //获取db所有表名称            ResultSet tableset =  data.getTables("orcl", "DEVH3IMAGE", null, new String[]{"TABLE"});            System.out.println("db中所有表名");            while (tableset.next()) {                System.out.print(tableset.getString("TABLE_NAME") + "\t");            }            System.out.println();            ResultSet colset =  data.getColumns("orcl", "DEVH3IMAGE", "T_YX_01",null);            System.out.println("表T_YX_01中的所有列名");            while (colset.next()) {                System.out.print(colset.getString("COLUMN_NAME") + "\t");            }            System.out.println();            //同样的 可以获取到db中所有的索引 存储过程 等等信息                        System.out.println("=====================================");                        //设置只读//            con.setReadOnly(true);            System.out.println("con is read only ? == "+con.isReadOnly());            //默认是自动提交事务            System.out.println("con is auto commit?==="+con.getAutoCommit());            System.out.println("=====================================");                        //普通查询            Statement st = con.createStatement();            ResultSet set = st.executeQuery("select * from t_yx_01");            st.close();                        //带参数查询            PreparedStatement pst = con.prepareStatement("select * from t_yx_01 where id = ?");            pst.setString(1, "1930128");            ResultSet prSet = pst.executeQuery();            ResultSetMetaData rdata =  prSet.getMetaData();            while (prSet.next()) {                for (int i = 1; i <= rdata.getColumnCount(); i++) {                    System.out.print(rdata.getColumnName(i) +":"+ prSet.getString(rdata.getColumnName(i)));                    System.out.print("\t");                }                System.out.println();            }            pst.close();                        System.out.println("=====================================");            con.close();        } catch (ClassNotFoundException e) {            e.printStackTrace();        } catch (SQLException e) {            //sqlexception中有sql自己的异常信息            System.out.println(e.getErrorCode());            System.out.println(e.getMessage());            System.out.println(e.getSQLState());            e.printStackTrace();        }