DatabaseMetaData

TABLE_CAT	String	The catalog name.
TABLE_SCHEM	String	The table schema name.
TABLE_NAME	String	The table name.
COLUMN_NAME	String	The column name.
DATA_TYPE	short	The SQL data type from java.sql.Types.
TYPE_NAME	String	The name of the data type.
COLUMN_SIZE	int	The precision of the column.
BUFFER_LENGTH	int	Not supported by the JDBC driver.
DECIMAL_DIGITS	int	The scale of the column.
NUM_PREC_RADIX	int	The radix of the column.
NULLABLE	int	Indicates if the column is nullable. It can be one of the following values: columnNoNulls (0) columnNullable (1) columnNullableUnknown (2)
REMARKS	String	The comments associated with the column. 注意： SQL Server always returns null for this column.
COLUMN_DEF	String	The default value of the column.
SQL_DATA_TYPE	int	Not supported by the JDBC driver.
SQL_DATETIME_SUB	int	Not supported by the JDBC driver.
CHAR_OCTET_LENGTH	int	The maximum number of bytes in the column.
ORDINAL_POSITION	int	The index of the column within the table.
IS_NULLABLE	String	Indicates if the column allows null values.

例子：

public static void executeGetColumns(Connection con) {
   try {
      DatabaseMetaData dbmd = con.getMetaData();
      ResultSet rs = dbmd.getColumns("AdventureWorks", "Person", "Contact", "FirstName");
      ResultSetMetaData rsmd = rs.getMetaData();

      // Display the result set data.
      int cols = rsmd.getColumnCount();
      while(rs.next()) {
         for (int i = 1; i <= cols; i++) {
            System.out.println(rs.getString(i));
         }
      }
      rs.close();
   } 

   catch (Exception e) {
      e.printStackTrace();
   }
}