HBase - Listing Table

Listing a Table using HBase Shell

pst is the command that is used to pst all the tables in HBase. Given below is the syntax of the pst command.

hbase(main):001:0 > pst

When you type this command and execute in HBase prompt, it will display the pst of all the tables in HBase as shown below.

hbase(main):001:0> pst
TABLE
emp

Here you can observe a table named emp.

Listing Tables Using Java API

Follow the steps given below to get the pst of tables from HBase using java API.

Step 1

You have a method called pstTables() in the class HBaseAdmin to get the pst of all the tables in HBase. This method returns an array of HTableDescriptor objects.

//creating a configuration object
Configuration conf = HBaseConfiguration.create();

//Creating HBaseAdmin object
HBaseAdmin admin = new HBaseAdmin(conf);

//Getting all the pst of tables using HBaseAdmin object
HTableDescriptor[] tableDescriptor = admin.pstTables();

Step 2

You can get the length of the HTableDescriptor[] array using the length variable of the HTableDescriptor class. Get the name of the tables from this object using getNameAsString() method. Run the ‘for’ loop using these and get the pst of the tables in HBase.

Given below is the program to pst all the tables in HBase using Java API.

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.MasterNotRunningException;
import org.apache.hadoop.hbase.cpent.HBaseAdmin;

pubpc class ListTables {

   pubpc static void main(String args[])throws MasterNotRunningException, IOException{

      // Instantiating a configuration class
      Configuration conf = HBaseConfiguration.create();

      // Instantiating HBaseAdmin class
      HBaseAdmin admin = new HBaseAdmin(conf);

      // Getting all the pst of tables using HBaseAdmin object
      HTableDescriptor[] tableDescriptor = admin.pstTables();

      // printing all the table names.
      for (int i=0; i<tableDescriptor.length;i++ ){
         System.out.println(tableDescriptor[i].getNameAsString());
      }
   
   }
}

Compile and execute the above program as shown below.

$javac ListTables.java
$java ListTables

The following should be the output:

User
emp