Create custom input column format FamilyInputFormat for cassandra

Question

I am working on a project using cassandra 1.2, hasoop 1.2

I created my usual cassandra mapper and reducer, but I want to create my own class Input format, which will read the entries from cassandra, and I will get the desired column value by separating this value using partitioning and indexing, so I planned to create my own Format class. but I'm confused and unable to find out how I would do this? Which classes should be extended and implemented, and how can I extract the row key, column name, column value, etc.

I have my own mapperclass as follows:

    public class MyMapper extends
            Mapper<ByteBuffer, SortedMap<ByteBuffer, IColumn>, Text, Text> {
        private Text word = new Text();
        MyJDBC db = new MyJDBC();

        public void map(ByteBuffer key, SortedMap<ByteBuffer, IColumn> columns,
                Context context) throws IOException, InterruptedException {

            long std_id = Long.parseLong(ByteBufferUtil.string(key));
            long newSavePoint = 0;
            if (columns.values().isEmpty()) {
            System.out.println("EMPTY ITERATOR");
            sb.append("column_N/A" + ":" + "N/A" + " , ");                  
            } else {
                for (IColumn cell : columns.values()) {
                    name = ByteBufferUtil.string(cell.name());
                    String value = null;
                    if (name.contains("int")) {
                    value = String.valueOf(ByteBufferUtil.toInt(cell.value()));
                    } else {
                    value = ByteBufferUtil.string(cell.value());
                    }
                String[] data = value.toString().split(",");
                // if (data[0].equalsIgnoreCase("login")) {
                    Long[] dif = getDateDiffe(d1, d2);

// logics i want to perform inside my custominput class , rather here, i just want a simple mapper class        
if (condition1 && condition2) {             
myhits++;
sb.append(":\t " + data[0] + "  " + data[2] + "  "+ data[1] /* + " " + data[3] */+ "\n");
newSavePoint = d2;
}
}
sb.append("~" + like + "~" + newSavePoint + "~");
word.set(sb.toString().replace("\t", ""));
}

db.setInterval(Long.parseLong(ByteBufferUtil.string(key)), newSavePoint);
db.setHits(Long.parseLong(ByteBufferUtil.string(key)), like + "");
context.write(new Text(ByteBufferUtil.string(key)), word);
}

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Answer 1

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