How do I get the number of columns of a table in hbase with java

Question

How can I get the number of columns of a table in HBASE using java

This is my code in java

HBASE Version

hbase(main):002:0> -version
2.0.0.3.0.1.0-187, re9fcf450949102de5069b257a6dee469b8f5aab3, Wed Sep 19 10:16:35 UTC 2018
Took 0.0004 seconds
NoMethodError: undefined method `-@' for nil:NilClass

I want to know if I am making the connection correctly or if something is missing or how can I correct On the other hand, the way to consult the name of the table and the number of columns is fine or something else should be added.

Java

package hbase;

import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.*;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.security.UserGroupInformation;

/**
 *
 * @author home
 */
public class HBase {

    /**
     * @param args the command line arguments
     * @throws org.apache.hadoop.hbase.MasterNotRunningException
     */
    protected  static Connection conn;
    
    public static void main(String[] args) throws MasterNotRunningException, IOException {
        String hbaseZookeeperQuorum = "pgdacl-hdpmg01.sitio.com,pgdacl-hdpmg02.sitio.com,pgdacl-hdpmg03.sitio.com";
        int hbaseZookeeperClientPort = 2181;
        String znodeParent = "/hbase-secure";
        String hadoopSecurity = "Kerberos";
        String userLogin = "[email protected]";
        String keyTab = "/etc/security/keytabs/gsioper.keytab";
        String hbaseSite = "/usr/hdp/3.0.1.0-187/hbase/conf/hbase-site.xml";
        //
        Configuration config = HBaseConfiguration.create();
        config.addResource(hbaseSite);
        config.set("hbase.zookeeper.quorum", hbaseZookeeperQuorum);
        config.setInt("hbase.zookeeper.property.clientPort", hbaseZookeeperClientPort);
        config.set("zookeeper.znode.parent", znodeParent);
        config.set("hadoop.security.authentication", hadoopSecurity);
        UserGroupInformation.setConfiguration(config);
        UserGroupInformation.loginUserFromKeytab(userLogin, keyTab);
        
        
        Connection connection = ConnectionFactory.createConnection(config);
        Table table = connection.getTable(TableName.valueOf("MONITOR:PARAMS_AIC"));
        Scan scan = new Scan();
        ResultScanner results = table.getScanner(scan);
        int count = 0;
        for (Result res : results) {
         count += res.size();
        }
        results.close();
        System.out.println("=========================================");
        System.out.println(count);
    }
    
}

hbase(main):001:0> !list
TABLE
MONITOR:BITACORA_CARGAS_SQOOP
MONITOR:CACHE_NIFI
MONITOR:CACHE_NIFI_EGCDR
MONITOR:CACHE_NIFI_PGWCDR_1
MONITOR:CACHE_NIFI_PGWCDR_2
MONITOR:EXAMPLE
MONITOR:LOGS
MONITOR:PARAMS_AIC
MONITOR:PARAMS_AIC3
MONITOR:PARTICIONES_DEPURACION
MONITOR:REPORTE_TMPORAL_01
MONITOR:STATS

I have this errors

what am I doing wrong