HBase與Jython一起使用

Jython

設置類路徑

要將Jython與HBase 一起使用，您的 CLASSPATH 必須包含 HBase 的類路徑以及代碼所需的 Jython JAR。

將路徑設置為包含 Jython .jar 的目錄，以及每個項目需要的附加的 Jython 相關 JAR。然后導出指向$ JYTHON_HOME 環(huán)境變量的 HBASE_CLASSPATH。

$ export HBASE_CLASSPATH=/directory/jython.jar

在類路徑中使用 HBase 和 Hadoop JAR 啟動 Jython shell：$ bin / hbase org.python.util.jython

Jython 代碼示例

使用 Jython 創(chuàng)建表，填充，獲取和刪除表

以下 Jython 代碼示例檢查表，如果存在，則刪除它然后創(chuàng)建它。然后，它使用數(shù)據(jù)填充表并獲取數(shù)據(jù)。

import java.lang
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.create()
connection = ConnectionFactory.createConnection(conf)
admin = connection.getAdmin()

# 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"))

# Drop and recreate if it exists
if admin.tableExists(tableName):
    admin.disableTable(tableName)
    admin.deleteTable(tableName)

admin.createTable(desc)

# Add content to 'column:' on a row named 'row_x'
row = 'row_x'
put = Put(row)
put.addColumn("content", "qual", "some content")
table.put(put)

# Now fetch the content just added, returns a byte[]
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

使用 Jython 進行表掃描

此示例掃描表并返回與給定族限定符匹配的結果。

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)

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.getValue(cf, attr))