incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Ivan Chang <ivan.ch...@medigy.com>
Subject Data persistency
Date Wed, 17 Jun 2009 20:54:18 GMT
I tried to insert and retrieve data from a standalone Java program.  While I
am able to insert and retrieve the correct data from within the Java
session.  After I terminate the session, and rerun only the data retrieval
part, the previous inserted data does not exist anymore, throwing a null
exception.  Here's the code:

        // Get storage-config file location

System.out.println("storage-config="+DatabaseDescriptor.getConfigFileName());

        // Insert some data with key "partner1"
        RowMutation rm = new RowMutation("Table1", "partner1");
        ColumnFamily cf = new ColumnFamily("Standard1", "Standard");
        long now = Calendar.getInstance().getTimeInMillis();
        System.out.println(now);
        cf.addColumn("firstname", "John1".getBytes(), now);
        cf.addColumn("lastname", "Doe1".getBytes(), now);
        rm.add(cf);
        try {
            rm.apply();
        } catch (Exception e) {
        }

        // Retrieve data for key "partner1"
        Table table = Table.open("Table1");

        try {
            Row result = table.getRow("partner1", "Standard1");
            System.out.println(result.toString());
            ColumnFamily cres = result.getColumnFamily("Standard1");
            Map cols = cres.getColumns();
            System.out.println(cols.size());
            Set c = cols.keySet();
            Iterator it = c.iterator();
            while (it.hasNext()) {
                String cn = (String) it.next();
                System.out.println(cn);
                System.out.println(new String(cres.getColumn(cn).value()));
            }
        } catch (Exception e) {
            System.out.println("Ex: " + e.getMessage());
        }

the print out from above is

storage-config=~/Cassandra/trunk/conf/storage-conf.xml
1245270260114
Row(partner1 [ColumnFamily(Standard1 [firstname:false:5@1245270260114,
lastname:false:4@1245270260114]))]
2
lastname
Doe1
firstname
John1

However, when I commented out the insert part of the above code and try
retrieve data again by rerunning the main code, I got an exception:

Row(partner1 [)]
Ex: null

So the data doesn't seem to persist across sessions.

Could someone explain what's wrong with the code?

Thanks,
Ivan

Mime
View raw message