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https://issues.apache.org/jira/browse/HBASE-2004?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12781475#action_12781475
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stack commented on HBASE-2004:
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+1 Sounds like good idea to me.
> Client javadoc suggestion: add code examples about obtaining historical
> values
> -------------------------------------------------------------------------------
>
> Key: HBASE-2004
> URL: https://issues.apache.org/jira/browse/HBASE-2004
> Project: Hadoop HBase
> Issue Type: Improvement
> Components: client
> Affects Versions: 0.20.1
> Reporter: Doug Meil
> Priority: Minor
>
> The implicit support HBase provides for versioning of values is very
> powerful, but it's not all that obvious for application programmers to use it
> to obtain the historical values.
> I would like to suggest adding some comments and sample code to the Result
> class (org.apache.hadoop.hbase.client.Result) Javadoc. I know this seems
> sort of obvious to people that regularly use HBase, but I think that for new
> folks having code examples available in Javadoc is helpful because it's "one
> stop shopping" for documentation (i.e., as opposed to looking to an external
> writeup). Arguably, this type of example could also go in the HTable class
> javadoc.
> e.g.,....
> HTable table = new HTable(config, "mytable");
> Scan scan = new Scan(); // no arguments indicates will scan all rows
> scan.setMaxVersions( 5 ); // setting this to 1 only returns
> current version
> ResultScanner rs = table.getScanner(scan);
> for (Iterator<Result> i = rs.iterator(); i.hasNext(); ) {
> Result r = i.next();
> // obtains current value from 'family:column'
> byte b[] = r.getValue( Bytes.toBytes("family"), Bytes.toBytes("column")
> );
> KeyValue kv[] = r.raw();
> for (int j = 0; j < kv.length; j++) {
>
> byte bv[] = kv[j].getValue();
> // this loop returns both current and historical values
> byte bc[] = kv[j].getColumn();
> // returns 'family:column'
> }
> }
>
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