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javacassandrahectorcassandra-cli

Fetch string from Hector QueryResult object


I am using Java Hector API to retrieve data from Cassandra databse as following:

public static void retrieveData() {
    try {
        //Create a cluster object from your existing Cassandra cluster
        Cluster cluster = HFactory.getOrCreateCluster("Test Cluster", "localhost:9160");

        //Create a keyspace object from the existing keyspace we created using CLI
        Keyspace keyspace = HFactory.createKeyspace("TestDB", cluster);

        SliceQuery<String, String, String> sliceQuery = HFactory.createSliceQuery(keyspace, stringSerializer, stringSerializer, stringSerializer);
        sliceQuery.setColumnFamily("ClientHeaders").setKey("1234");
        sliceQuery.setRange("", "", false, 10);
        sliceQuery.setColumnNames("ip_address","uuid");
        QueryResult<ColumnSlice<String, String>> result = sliceQuery.execute();                 
        System.out.println("\nInserted data is as follows:\n" + result.get());   
    } catch (Exception ex) {
        System.out.println("Error encountered while retrieving data!!");
        ex.printStackTrace() ;
    }

So I get the retrieved values according to query in this order:

ColumnSlice([HColumn(ip_address=203.110.85.171), HColumn(uuid=a3363400-abfd-0130-e2cf-07b5c765964c)])

However I want to extract the result in some string variable (string ip=ip_address etc) and use. But I couldn't find out how to do that ? Please help. Thanks.


Solution

  • Try doing this:

     if (result != null && result.get() != null) {
                List<HColumn<String, String>> resultCols = result.get().getColumns();
                for (HColumn<String, String> col : resultCols)
                {
                   System.out.println(col.getValue());
                }