HBase - Hadoop: The Definitive Guide - page 710

ResultScanner scanner = table . getScanner ( scan );
try {
for ( Result scannerResult : scanner ) {
System . out . println ( "Scan: " + scannerResult );
}
} finally {
scanner . close ();
}
// Disable then drop the table
admin . disableTable ( tableName );
admin . deleteTable ( tableName );
} finally {
table . close ();
}
} finally {
admin . close ();
}
}
}
This class has a main() method only. For the sake of brevity, we do not include the
package name, nor imports. Most of the HBase classes are found in the
org.apache.hadoop.hbase and org.apache.hadoop.hbase.client pack-
ages.
In this class, we first ask the HBaseConfiguration class to create a Configura-
tion object. It will return a Configuration that has read the HBase configuration
from the hbase-site.xml and hbase-default.xml files found on the program's classpath.
This Configuration is subsequently used to create instances of HBaseAdmin and
HTable . HBaseAdmin is used for administering your HBase cluster, specifically for
adding and dropping tables. HTable is used to access a specific table. The Configur-
ation instance points these classes at the cluster the code is to work against.
NOTE
From HBase 1.0, there is a new client API that is cleaner and more intuitive. The constructors of
HBaseAdmin and HTable have been deprecated, and clients are discouraged from making explicit ref-
erence to these old classes. In their place, clients should use the new ConnectionFactory class to
create a Connection object, then call getAdmin() or getTable() to retrieve an Admin or
Table instance, as appropriate. Connection management was previously done for the user under the
covers, but is now the responsibility of the client. You can find versions of the examples in this chapter
updated to use the new API on this topic's accompanying website.