Apache
/
hbase
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

HBASE-18269 Jython docs out of date 

Signed-off-by: Mike Drob <mdrob@apache.org>
This commit is contained in:
Artem Ervits 2018-06-20 09:42:38 -07:00 committed by Mike Drob
parent 8341237ddd
commit d1cad1a254
No known key found for this signature in database
GPG Key ID: 3E48C0C6EF362B9E
1 changed files with 44 additions and 57 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

99
src/main/asciidoc/_chapters/external_apis.adoc
View File

@ -851,23 +851,14 @@ println(Bytes.toString(value))
=== Setting the Classpath
To use Jython with HBase, your CLASSPATH must include HBase's classpath as well as
the Jython JARs required by your code. First, use the following command on a server
running the HBase RegionServer process, to get HBase's classpath.
the Jython JARs required by your code.
Set the path to directory containing the `jython.jar` and each additional Jython-related JAR needed for
your project. Then export HBASE_CLASSPATH pointing to the $JYTHON_HOME env. variable.
[source, bash]
----
$ ps aux |grep regionserver| awk -F 'java.library.path=' {'print $2'} | awk {'print $1'}
/usr/lib/hadoop/lib/native:/usr/lib/hbase/lib/native/Linux-amd64-64
----
Set the `$CLASSPATH` environment variable to include the path you found in the previous
step, plus the path to `jython.jar` and each additional Jython-related JAR needed for
your project.
[source, bash]
----
$ export CLASSPATH=$CLASSPATH:/usr/lib/hadoop/lib/native:/usr/lib/hbase/lib/native/Linux-amd64-64:/path/to/jython.jar
$ export HBASE_CLASSPATH=/directory/jython.jar
----
Start a Jython shell with HBase and Hadoop JARs in the classpath:
@ -877,55 +868,52 @@ $ bin/hbase org.python.util.jython
.Table Creation, Population, Get, and Delete with Jython
====
The following Jython code example creates a table, populates it with data, fetches
the data, and deletes the table.
The following Jython code example checks for table,
if it exists, deletes it and then creates it. Then it
populates the table with data and fetches the data.
[source,jython]
----
import java.lang
from org.apache.hadoop.hbase import HBaseConfiguration, HTableDescriptor, HColumnDescriptor, HConstants, TableName
from org.apache.hadoop.hbase.client import HBaseAdmin, HTable, Get
from org.apache.hadoop.hbase.io import Cell, RowResult
from org.apache.hadoop.hbase import HBaseConfiguration, HTableDescriptor, HColumnDescriptor, TableName
from org.apache.hadoop.hbase.client import Admin, Connection, ConnectionFactory, Get, Put, Result, Table
from org.apache.hadoop.conf import Configuration
# First get a conf object. This will read in the configuration
# that is out in your hbase-*.xml files such as location of the
# hbase master node.
conf = HBaseConfiguration()
conf = HBaseConfiguration.create()
connection = ConnectionFactory.createConnection(conf)
admin = connection.getAdmin()
# Create a table named 'test' that has two column families,
# one named 'content, and the other 'anchor'. The colons
# are required for column family names.
tablename = TableName.valueOf("test")
# Create a table named 'test' that has a column family
# named 'content'.
tableName = TableName.valueOf("test")
table = connection.getTable(tableName)
desc = HTableDescriptor(tablename)
desc.addFamily(HColumnDescriptor("content:"))
desc.addFamily(HColumnDescriptor("anchor:"))
admin = HBaseAdmin(conf)
desc = HTableDescriptor(tableName)
desc.addFamily(HColumnDescriptor("content"))
# Drop and recreate if it exists
if admin.tableExists(tablename):
admin.disableTable(tablename)
admin.deleteTable(tablename)
admin.createTable(desc)
if admin.tableExists(tableName):
admin.disableTable(tableName)
admin.deleteTable(tableName)
tables = admin.listTables()
table = HTable(conf, tablename)
admin.createTable(desc)
# Add content to 'column:' on a row named 'row_x'
row = 'row_x'
update = Get(row)
update.put('content:', 'some content')
table.commit(update)
put = Put(row)
put.addColumn("content", "qual", "some content")
table.put(put)
# Now fetch the content just added, returns a byte[]
data_row = table.get(row, "content:")
data = java.lang.String(data_row.value, "UTF8")
get = Get(row)
result = table.get(get)
data = java.lang.String(result.getValue("content", "qual"), "UTF8")
print "The fetched row contains the value '%s'" % data
# Delete the table.
admin.disableTable(desc.getName())
admin.deleteTable(desc.getName())
----
====
@ -935,24 +923,23 @@ This example scans a table and returns the results that match a given family qua
[source, jython]
----
# Print all rows that are members of a particular column family
# by passing a regex for family qualifier
import java.lang
from org.apache.hadoop.hbase import TableName, HBaseConfiguration
from org.apache.hadoop.hbase.client import Connection, ConnectionFactory, Result, ResultScanner, Table, Admin
from org.apache.hadoop.conf import Configuration
conf = HBaseConfiguration.create()
connection = ConnectionFactory.createConnection(conf)
admin = connection.getAdmin()
tableName = TableName.valueOf('wiki')
table = connection.getTable(tableName)
from org.apache.hadoop.hbase import HBaseConfiguration
from org.apache.hadoop.hbase.client import HTable
conf = HBaseConfiguration()
table = HTable(conf, "wiki")
col = "title:.*$"
scanner = table.getScanner([col], "")
cf = "title"
attr = "attr"
scanner = table.getScanner(cf)
while 1:
result = scanner.next()
if not result:
break
print java.lang.String(result.row), java.lang.String(result.get('title:').value)
print java.lang.String(result.row), java.lang.String(result.getValue(cf, attr))
----
====