JsonMarshaller.java

package com.hmsonline.virgil;

import java.io.UnsupportedEncodingException;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.MalformedInputException;
import java.util.List;

import org.apache.cassandra.thrift.CfDef;
import org.apache.cassandra.thrift.Column;
import org.apache.cassandra.thrift.ColumnOrSuperColumn;
import org.apache.cassandra.thrift.KeySlice;
import org.apache.cassandra.thrift.KsDef;
import org.apache.cassandra.utils.ByteBufferUtil;
import org.apache.cassandra.utils.UUIDGen;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;

public class JsonMarshaller {

    @SuppressWarnings("unchecked")
    public static String marshallColumn(ColumnOrSuperColumn column) throws UnsupportedEncodingException {
        JSONObject json = new JSONObject();
        Column c = column.getColumn();
        json.put(string(c.getName()), string(c.getValue()));
        return json.toString();
    }

    @SuppressWarnings("unchecked")
    public static JSONObject marshallSlice(List<ColumnOrSuperColumn> slice) throws UnsupportedEncodingException {
        JSONObject json = new JSONObject();
        for (ColumnOrSuperColumn column : slice) {
            Column c = column.getColumn();
            json.put(string(c.getName()), string(c.getValue()));
        }
        return json;
    }

    @SuppressWarnings("unchecked")
	public static JSONArray marshallRows(List<KeySlice> rows, boolean flatten) throws CharacterCodingException  {
		if (flatten){
			JSONArray cfJson = new JSONArray();
			for (KeySlice row : rows){
			    
				String rowKey = null;
				try {
				    rowKey = ByteBufferUtil.string(row.key);
				} catch (Exception e){
				    // TODO: Be smarter, use the ValidationClass to marshal to a string
				    rowKey = UUIDGen.getUUID(row.key).toString();
				}
				for (ColumnOrSuperColumn column : row.columns){
					JSONObject rowJson = new JSONObject();
					rowJson.put("row", rowKey);
					try {
						rowJson.put("column", ByteBufferUtil.string(column.column.name));
					} catch (MalformedInputException mfie){
						rowJson.put("column", "NON-STRING (Support for non-strings is coming)");						
					}
					try {
						rowJson.put("value", ByteBufferUtil.string(column.column.value));
					} catch (MalformedInputException mfie){
						rowJson.put("value", "NON-STRING (Support for non-strings is coming)");
					}
					cfJson.add(rowJson);
				}
			}
			return cfJson;
		} else {
			throw new RuntimeException("Virgil does not support hiearchical fetch of column family yet.");
		}		
	}

    @SuppressWarnings("unchecked")
    public static JSONArray marshallKeyspaces(List<KsDef> keyspaces, boolean flatten)
            throws UnsupportedEncodingException {
        JSONArray keyspaceJson = new JSONArray();
        if (flatten) {
            for (KsDef keyspace : keyspaces) {
                List<CfDef> columnFamilies = keyspace.getCf_defs();
                for (CfDef columnFamily : columnFamilies) {
                    JSONObject json = new JSONObject();
                    json.put("keyspace", keyspace.getName());
                    json.put("columnFamily", columnFamily.getName());
                    keyspaceJson.add(json);
                }
            }
        } else {
            for (KsDef keyspace : keyspaces) {
                JSONObject json = new JSONObject();
                json.put("keyspace", keyspace.getName());
                json.put("strategy", keyspace.getStrategy_class());
                List<CfDef> columnFamilies = keyspace.getCf_defs();
                JSONArray cfJsonArray = new JSONArray();
                for (CfDef columnFamily : columnFamilies) {
                    JSONObject cfJson = new JSONObject();
                    cfJson.put("name", columnFamily.getName());
                    cfJsonArray.add(cfJson);
                }
                json.put("columnFamilies", cfJsonArray);
                keyspaceJson.add(json);
            }
        }
        return keyspaceJson;
    }

    private static String string(byte[] bytes) throws UnsupportedEncodingException {
        return new String(bytes, "UTF8");
    }

}

/* TOMBSTONE */

/*
 * 
 * public static JSONArray flatten (JSONArray original) { JSONArray flatJson =
 * new JSONArray(); JSONObject parentAttributes = new JSONObject();
 * JsonMarshaller.flattenHelper(parentAttributes, original, flatJson); return
 * flatJson; }
 * 
 * @SuppressWarnings("unchecked") public static void flattenHelper (JSONObject
 * parentAttributes, Object node, JSONArray flatJson) { if (node instanceof
 * JSONArray){ JSONArray array = (JSONArray) node; Iterator<JSONObject> iter =
 * array.iterator(); while(iter.hasNext()){ Object child = iter.next();
 * JsonMarshaller.flattenHelper(parentAttributes, child, flatJson); } } }
 */