View HBase Namespace Tables | Fast Guide

To view tables under an HBase namespace, you can utilize either the HBase Shell command or the HBase Java API.

1. View tables in a namespace using HBase Shell command.
2. Open the terminal and enter the HBase Shell.
3. Execute the following command: list_namespace_tables ‘namespace name’.
4. Replace ‘namespace name’ with the name of the namespace you want to view.
5. Display all tables under the namespace.
6. View tables under a namespace using the HBase Java API.
7. Create an HBase connection and Admin object in Java code.
8. Use the listTableNamesByNamespace method of the Admin object to obtain TableName objects for all tables under the specified namespace.
9. Iterate through TableName objects and print the names of the tables.

Here is an example code using the Java API:

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.NamespaceDescriptor;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Admin;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;

public class ListTablesInNamespace {
  public static void main(String[] args) throws Exception {
    // 创建HBase配置
    Configuration config = HBaseConfiguration.create();
    // 创建HBase连接
    Connection connection = ConnectionFactory.createConnection(config);
    // 创建Admin对象
    Admin admin = connection.getAdmin();

    // 命名空间名称
    String namespaceName = "命名空间名称";

    // 获取命名空间描述符
    NamespaceDescriptor namespaceDescriptor = admin.getNamespaceDescriptor(namespaceName.getBytes());
    
    // 获取命名空间下的所有表
    TableName[] tableNames = admin.listTableNamesByNamespace(namespaceDescriptor.getName());

    // 打印表的名称
    for (TableName tableName : tableNames) {
      System.out.println(tableName.getNameAsString());
    }

    // 关闭连接
    admin.close();
    connection.close();
  }
}

Please make sure to replace ‘namespace name’ in the code with the actual namespace name.