try {
HConnection conn = HConnectionManager.getConnection(conf);
if (!conn.tableExists(this.tableName)) {
return new ReturnMsg(0, "Table not found");
}
HTableDescriptor [] tables = conn.listTables();
HColumnDescriptor [] columns = null;
for (int i = 0; i < tables.length; i++) {
if (tables[i].getName().equals(this.tableName)) {
columns = tables[i].getFamilies().values().
toArray(new HColumnDescriptor [] {});