Write Once、Run Anywhere

创建一个字符串实例变量StringBuffer buf = new StringBuffer("Java");    // Append    buf.append(" Almanac v1/");      // Java Almanac v1/    buf.append(3);                   // Java Almanac v1/3       

加载JDBC驱动try {        // Load the JDBC driver 加载指定名称的类        String driverName = "org.gjt.mm.mysql.Driver";        Class.forName(driverName);    } catch (ClassNotFoundException e) {       

获取表中的 行 信息try {        // 获取指定数据库表的全部的行数据        Statement stmt = connection.createStatement();        ResultSet rs = stmt.executeQuery("SELECT * FROM my_table");    } catch (SQLException e)

查询数据库是否支持游标回滚操作try {        DatabaseMetaData dmd = connection.getMetaData();        if (dmd.supportsResultSetType(ResultSet.TYPE_SCROLL_INSENSITIVE)) {            // Insensitive scrollable res

查询结果集是否支持更新操作try {        DatabaseMetaData dmd = connection.getMetaData();        if (dmd.supportsResultSetConcurrency(            ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_UPDATABLE)) {