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HBase, mail # user - connecting Hbase using java


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Re: connecting Hbase using java
Jean-Marc Spaggiari 2013-04-04, 15:13
Alok,

Can you take a deeper look in your code and your logs before asking
someone to solve that for you? ;)

Your CF is called "myColumnFamily" and not "myLittleFamily".

Also, I will recommand you to read some HBase related books where you
will learn that column familly names need to be as small as
possible... one byte is the best.

JM

2013/4/4 Alok Singh Mahor <[EMAIL PROTECTED]>:
> yes thank you so much jean, I will switch to eclipse.
>
> now I tried with (java -classpath `~/packages/hbase-0.94.6/bin/hbase
> classpath` MyLittleHBaseClient)
>
> code is running but I guess now I have some problem with my hbase and hadoop
>
> I am getting output that you can see at http://paste.ubuntu.com/5676866/
> could you please figure out where things are wrong now?
> thanks again, your reply are helping me learning basic things.
>
>
>
> On Thu, Apr 4, 2013 at 8:11 PM, Jean-Marc Spaggiari <[EMAIL PROTECTED]
>> wrote:
>
>> Alok,
>>
>> I definitively recommand you to use an IDE to test your code. That
>> will help you a lot.
>>
>> Again, here, you are simply missing the classpath for you "java" command.
>>
>> JM
>>
>> 2013/4/4 Alok Singh Mahor <[EMAIL PROTECTED]>:
>> > wow I am not getting any error now while compiling using (javac
>> -classpath
>> > `~/packages/hbase-0.94.6/bin/hbase classpath` MyLittleHBaseClient.java)
>> >
>> > but this time I am getting runtime error
>> >
>> > alok@alok:~/exp/hbase/exp$ javac -classpath
>> > `~/packages/hbase-0.94.6/bin/hbase classpath` MyLittleHBaseClient.java
>> > alok@alok:~/exp/hbase/exp$ java MyLittleHBaseClient
>> > Exception in thread "main" java.lang.NoClassDefFoundError:
>> > org/apache/hadoop/hbase/HBaseConfiguration
>> >         at MyLittleHBaseClient.main(MyLittleHBaseClient.java:15)
>> > Caused by: java.lang.ClassNotFoundException:
>> > org.apache.hadoop.hbase.HBaseConfiguration
>> >         at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
>> >         at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
>> >         at java.security.AccessController.doPrivileged(Native Method)
>> >         at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
>> >         at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
>> >         at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
>> >         at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
>> >         ... 1 more
>> > alok@alok:~/exp/hbase/exp$
>> >
>> > you can see the code I am compiling at http://paste.ubuntu.com/5676812/
>> >
>> > hadoop and hbase are running and I before running I had create table in
>> > Hbase shell
>> >
>> > hbase(main):001:0> create 'myTable', 'myColumnFamily'
>> > 0 row(s) in 2.3800 seconds
>> >
>> > hbase(main):002:0> scan 'myTable'
>> > ROW
>> > COLUMN+CELL
>> >
>> > 0 row(s) in 0.1020 seconds
>> >
>> >
>> >
>> >
>> > On Thu, Apr 4, 2013 at 7:08 PM, Jean-Marc Spaggiari <
>> [EMAIL PROTECTED]
>> >> wrote:
>> >
>> >> org.apache.hadoop.conf.Configuration is missing from the imports...
>> >>
>> >> 2013/4/4 Alok Singh Mahor <[EMAIL PROTECTED]>:
>> >> > thanks again JM :)
>> >> > you gave very important clue.
>> >> >
>> >> > now am trying example code in
>> >> >
>> >>
>> http://hbase.apache.org/0.94/apidocs/org/apache/hadoop/hbase/client/package-summary.html#package_description
>> >> >
>> >> > using the command
>> >> > alok@alok:~/exp/hbase/exp$ javac -classpath
>> >> > `~/packages/hbase-0.94.6/bin/hbase classpath` MyLittleHBaseClient.java
>> >> >
>> >> > I am getting only one error this time. that I could not figure out.
>> so I
>> >> > still need help. please look on he error
>> >> >
>> >> > <error>
>> >> > alok@alok:~/exp/hbase/exp$ javac -classpath
>> >> > `~/packages/hbase-0.94.6/bin/hbase classpath` MyLittleHBaseClient.java
>> >> > MyLittleHBaseClient.java:21: error: cannot find symbol
>> >> >     Configuration config = HBaseConfiguration.create();
>> >> >     ^
>> >> >   symbol:   class Configuration
>> >> >   location: class MyLittleHBaseClient
>> >> > 1 error