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Last active August 29, 2015 14:03
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package basho.riak;
import com.basho.riak.client.RiakClient;
import com.basho.riak.client.operations.FetchDatatype;
import com.basho.riak.client.operations.FetchSet;
import com.basho.riak.client.operations.UpdateSet;
import com.basho.riak.client.operations.datatypes.SetUpdate;
import com.basho.riak.client.operations.indexes.BinIndexQuery;
import com.basho.riak.client.operations.kv.DeleteValue;
import com.basho.riak.client.operations.kv.FetchValue;
import com.basho.riak.client.operations.kv.StoreValue;
import com.basho.riak.client.query.Location;
import com.basho.riak.client.query.Namespace;
import com.basho.riak.client.query.RiakObject;
import com.basho.riak.client.query.indexes.StringBinIndex;
import com.basho.riak.client.util.BinaryValue;
import com.fasterxml.jackson.databind.ObjectMapper;
import java.util.*;
public class Column<T> {
public String columnName;
private Namespace bucket;
public RiakClient client;
private Location setLocation;
public Column(String columnName, RiakClient client) {
this.columnName = columnName;
this.client = client;
this.bucket = new Namespace(columnName);
this.setLocation = new Location(new Namespace("sets", columnName), "keys");
// Basic object fetch on the basis of its key
private Map getColumnObject(String key) throws Exception {
Location loc = new Location(bucket, key);
FetchValue fetch = new FetchValue.Builder(loc).build();
return client.execute(fetch).getValue(Map.class);
// Outputs the entire column as JSON, i.e. {"column":"<name>","objects":[...]}
public String asJson() throws Exception {
HashMap<String, Object> map = new HashMap<>();
List<Map> objects = getObjects();
map.put("objects", objects);
map.put("column", columnName);
return new ObjectMapper().writeValueAsString(map);
// Retrieves the column's keys on the basis of 2i
public Set<String> getKeys() throws Exception {
Set<String> builder = new HashSet<>();
Location loc = setLocation;
FetchSet fetch = new FetchSet.Builder(loc).build();
client.execute(fetch).getDatatype().viewAsSet().forEach((BinaryValue bin) -> {
return builder;
// Assembles a list of objects on the basis of the getKeys() operation
public List<Map> getObjects() throws Exception {
Set<String> keys = getKeys();
List<Map> builder = new ArrayList<Map>();
for (String key : keys) {
Map obj = getColumnObject(key);
return builder;
// Assembles a list of values for a single field for all objects in the column
public List<Object> getField(String field)
throws Exception {
List<Map> maps = getObjects();
List<Object> objects = new ArrayList<Object>();
maps.forEach((Map m) -> {
if (m.containsKey(field)) {
return objects;
// Adds an object to the column. Must be a Map.
public void addObject(String key, Map object) throws Exception {
Location loc = new Location(bucket, key);
String json = new ObjectMapper().writeValueAsString(object);
RiakObject obj = new RiakObject()
StoreValue store = new StoreValue.Builder(obj)
SetUpdate addKey = new SetUpdate()
UpdateSet update = new UpdateSet.Builder(setLocation, addKey).build();
// Removes an object from the column on the basis of its key
public void removeObject(String key) throws Exception {
Location loc = new Location(bucket, key);
DeleteValue delete = new DeleteValue.Builder(loc).build();
// Returns a list of objects that meet a field-level criterion, e.g. all objects
// for which the field "foo" equals ["bar", "baq", "baz"]
public List<Map> selectObjects(String field, Object comparison) throws Exception {
List<Map> builder = new ArrayList<>();
List<Map> maps = getObjects();
maps.forEach((Map m) -> {
if (m.containsKey(field) && m.get(field).equals(comparison)) {
return builder;
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