WRONGTYPE Operation against a key holding the wrong kind of value

I am looping through an arrayList and using redis rpush function to store strings in redis .However,I am getting the following error: WRONGTYPE Operation against a key holding the wrong kind of value

 for(String abc:myList) {    jedis.rpush(abc,(String[]) myList.toArray(new String[myList.size()]));

Thanks in advance!