CODEWITHSUNDEEP
javalistcassandrablobcql3
a_p
a_p

Reputation: 71

Retrieving List<blob> cassandra example

I am trying to insert some java object as a list into cassandra. I have a serializable java class I insert them as :

public void storeFeatures(java.util.Vector features){

        java.util.UUID uuid =   java.util.UUID.randomUUID();
        java.util.List<ByteBuffer> ls=new java.util.ArrayList<ByteBuffer>();
        for(int i=0;i<features.size();i++) {
           my.package.Feature f=(my.package.Feature)features.elementAt(i);
            byte[]b=(new ObjectToBytes()).getBytes(f);
            ls.add(java.nio.ByteBuffer.wrap(b));
         }
        session.execute("INSERT INTO mytable ( id, features) values ( ?, ? )", uuid, ls);
    }

But, somehow I can not retrieve them with

public java.util.List getFeatures(){

        java.util.List<ByteBuffer> ret=null;
        ResultSet rows = session.execute("SELECT * FROM imgs limit 10");
        for(Row row: rows){            
            row.getBytes("features");
            ret=row.getList("features",java.nio.ByteBuffer.class);

        }
        return ret;
    }

I get 

com.datastax.driver.core.exceptions.InvalidTypeException: Column features is of type list<blob>
    at com.datastax.driver.core.ColumnDefinitions.checkType(ColumnDefinitions.java:291)

How can I retrieve list < blob > types as list < ByteBuffer >?

Upvotes: 1

Views: 2481

Answers (1)

Mikhail Stepura
Mikhail Stepura

Reputation: 3374

To leave an answer: there was unnecessary call to row.getBytes("features"); which caused the error

Upvotes: 2

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