CREATE TABLE T (
  A INTEGER,
  B DOUBLE,
  C DECFOLAT,
  D DECIMAL( 10 , 2 )
)

String driverName = "com.ibm.db2.jcc.DB2Driver"
Connection con;
DatabaseMetaData dmd = con.getMetaData();
ResultSet rs = dmd.getColumn(null, schema_name, "T", null);

while(rs.next()) { ... }

String query = "SELECT * FROM T WHERE 0=1";
PreparedStatement stmt = con.prepareStatement(query);

try {
   ResultSet rs = stmt.executeQuery();
         
   try {
      ResultSetMetaData metaData = rs.getMetaData();            
      int count = metaData.getColumnCount();

      for(int i =  1 ; i <= count; i++) { ... }
   }
   finally { rs.close(); }
}
finally { stmt.close(); }