/**
* Insert a record in the database. Any field/value pairs in the specified values HashMap will be
* written into the record with the specified record key.
*
* @param table The name of the table
* @param key The record key of the record to insert.
* @param values A HashMap of field/value pairs to insert in the record
* @return Zero on success, a non-zero error code on error
*/
public int insert(String table, String key, HashMap<String, ByteIterator> values) {
if (!_table.equals(table)) {
try {
client.set_keyspace(table);
_table = table;
} catch (Exception e) {
e.printStackTrace();
e.printStackTrace(System.out);
return Error;
}
}
for (int i = 0; i < OperationRetries; i++) {
if (_debug) {
System.out.println("Inserting key: " + key);
}
try {
ByteBuffer wrappedKey = ByteBuffer.wrap(key.getBytes("UTF-8"));
ColumnOrSuperColumn column;
for (Map.Entry<String, ByteIterator> entry : values.entrySet()) {
column = new ColumnOrSuperColumn();
Column subColumn = new Column(ByteBuffer.wrap(entry.getKey().getBytes("UTF-8")));
subColumn.setValue(ByteBuffer.wrap(entry.getValue().toArray()));
subColumn.setTimestamp(System.currentTimeMillis());
column.setColumn(subColumn);
mutations.add(new Mutation().setColumn_or_supercolumn(column));
}
mutationMap.put(column_family, mutations);
record.put(wrappedKey, mutationMap);
client.batch_mutate(record, ConsistencyLevel.ONE);
mutations.clear();
mutationMap.clear();
record.clear();
return Ok;
} catch (Exception e) {
errorexception = e;
}
try {
Thread.sleep(500);
} catch (InterruptedException e) {
}
}
errorexception.printStackTrace();
errorexception.printStackTrace(System.out);
return Error;
}
/**
* Delete a record from the database.
*
* @param table The name of the table
* @param key The record key of the record to delete.
* @return Zero on success, a non-zero error code on error
*/
public int delete(String table, String key) {
if (!_table.equals(table)) {
try {
client.set_keyspace(table);
_table = table;
} catch (Exception e) {
e.printStackTrace();
e.printStackTrace(System.out);
return Error;
}
}
for (int i = 0; i < OperationRetries; i++) {
try {
client.remove(
ByteBuffer.wrap(key.getBytes("UTF-8")),
new ColumnPath(column_family),
System.currentTimeMillis(),
ConsistencyLevel.ONE);
if (_debug) {
System.out.println("Delete key: " + key);
}
return Ok;
} catch (Exception e) {
errorexception = e;
}
try {
Thread.sleep(500);
} catch (InterruptedException e) {
}
}
errorexception.printStackTrace();
errorexception.printStackTrace(System.out);
return Error;
}
/**
* Initialize any state for this DB. Called once per DB instance; there is one DB instance per
* client thread.
*/
public void init() throws DBException {
String hosts = getProperties().getProperty("hosts");
if (hosts == null) {
throw new DBException("Required property \"hosts\" missing for CassandraClient");
}
column_family =
getProperties().getProperty(COLUMN_FAMILY_PROPERTY, COLUMN_FAMILY_PROPERTY_DEFAULT);
parent = new ColumnParent(column_family);
ConnectionRetries =
Integer.parseInt(
getProperties()
.getProperty(CONNECTION_RETRY_PROPERTY, CONNECTION_RETRY_PROPERTY_DEFAULT));
OperationRetries =
Integer.parseInt(
getProperties()
.getProperty(OPERATION_RETRY_PROPERTY, OPERATION_RETRY_PROPERTY_DEFAULT));
String username = getProperties().getProperty(USERNAME_PROPERTY);
String password = getProperties().getProperty(PASSWORD_PROPERTY);
_debug = Boolean.parseBoolean(getProperties().getProperty("debug", "false"));
String[] allhosts = hosts.split(",");
String myhost = allhosts[random.nextInt(allhosts.length)];
Exception connectexception = null;
for (int retry = 0; retry < ConnectionRetries; retry++) {
tr = new TFramedTransport(new TSocket(myhost, 9160));
TProtocol proto = new TBinaryProtocol(tr);
client = new Cassandra.Client(proto);
try {
tr.open();
connectexception = null;
break;
} catch (Exception e) {
connectexception = e;
}
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
}
}
if (connectexception != null) {
System.err.println(
"Unable to connect to " + myhost + " after " + ConnectionRetries + " tries");
System.out.println(
"Unable to connect to " + myhost + " after " + ConnectionRetries + " tries");
throw new DBException(connectexception);
}
if (username != null && password != null) {
Map<String, String> cred = new HashMap<String, String>();
cred.put("username", username);
cred.put("password", password);
AuthenticationRequest req = new AuthenticationRequest(cred);
try {
client.login(req);
} catch (Exception e) {
throw new DBException(e);
}
}
}
/**
* Perform a range scan for a set of records in the database. Each field/value pair from the
* result will be stored in a HashMap.
*
* @param table The name of the table
* @param startkey The record key of the first record to read.
* @param recordcount The number of records to read
* @param fields The list of fields to read, or null for all of them
* @param result A Vector of HashMaps, where each HashMap is a set field/value pairs for one
* record
* @return Zero on success, a non-zero error code on error
*/
public int scan(
String table,
String startkey,
int recordcount,
Set<String> fields,
Vector<HashMap<String, ByteIterator>> result) {
if (!_table.equals(table)) {
try {
client.set_keyspace(table);
_table = table;
} catch (Exception e) {
e.printStackTrace();
e.printStackTrace(System.out);
return Error;
}
}
for (int i = 0; i < OperationRetries; i++) {
try {
SlicePredicate predicate;
if (fields == null) {
predicate =
new SlicePredicate()
.setSlice_range(new SliceRange(emptyByteBuffer, emptyByteBuffer, false, 1000000));
} else {
ArrayList<ByteBuffer> fieldlist = new ArrayList<ByteBuffer>(fields.size());
for (String s : fields) {
fieldlist.add(ByteBuffer.wrap(s.getBytes("UTF-8")));
}
predicate = new SlicePredicate().setColumn_names(fieldlist);
}
KeyRange kr =
new KeyRange()
.setStart_key(startkey.getBytes("UTF-8"))
.setEnd_key(new byte[] {})
.setCount(recordcount);
List<KeySlice> results =
client.get_range_slices(parent, predicate, kr, ConsistencyLevel.ONE);
if (_debug) {
System.out.println("Scanning startkey: " + startkey);
}
HashMap<String, ByteIterator> tuple;
for (KeySlice oneresult : results) {
tuple = new HashMap<String, ByteIterator>();
Column column;
String name;
ByteIterator value;
for (ColumnOrSuperColumn onecol : oneresult.columns) {
column = onecol.column;
name =
new String(
column.name.array(),
column.name.position() + column.name.arrayOffset(),
column.name.remaining());
value =
new ByteArrayByteIterator(
column.value.array(),
column.value.position() + column.value.arrayOffset(),
column.value.remaining());
tuple.put(name, value);
if (_debug) {
System.out.print("(" + name + "=" + value + ")");
}
}
result.add(tuple);
if (_debug) {
System.out.println();
}
}
return Ok;
} catch (Exception e) {
errorexception = e;
}
try {
Thread.sleep(500);
} catch (InterruptedException e) {
}
}
errorexception.printStackTrace();
errorexception.printStackTrace(System.out);
return Error;
}
/**
* Read a record from the database. Each field/value pair from the result will be stored in a
* HashMap.
*
* @param table The name of the table
* @param key The record key of the record to read.
* @param fields The list of fields to read, or null for all of them
* @param result A HashMap of field/value pairs for the result
* @return Zero on success, a non-zero error code on error
*/
public int read(
String table, String key, Set<String> fields, HashMap<String, ByteIterator> result) {
if (!_table.equals(table)) {
try {
client.set_keyspace(table);
_table = table;
} catch (Exception e) {
e.printStackTrace();
e.printStackTrace(System.out);
return Error;
}
}
for (int i = 0; i < OperationRetries; i++) {
try {
SlicePredicate predicate;
if (fields == null) {
predicate =
new SlicePredicate()
.setSlice_range(new SliceRange(emptyByteBuffer, emptyByteBuffer, false, 1000000));
} else {
ArrayList<ByteBuffer> fieldlist = new ArrayList<ByteBuffer>(fields.size());
for (String s : fields) {
fieldlist.add(ByteBuffer.wrap(s.getBytes("UTF-8")));
}
predicate = new SlicePredicate().setColumn_names(fieldlist);
}
List<ColumnOrSuperColumn> results =
client.get_slice(
ByteBuffer.wrap(key.getBytes("UTF-8")), parent, predicate, ConsistencyLevel.ONE);
if (_debug) {
System.out.print("Reading key: " + key);
}
Column column;
String name;
ByteIterator value;
for (ColumnOrSuperColumn oneresult : results) {
column = oneresult.column;
name =
new String(
column.name.array(),
column.name.position() + column.name.arrayOffset(),
column.name.remaining());
value =
new ByteArrayByteIterator(
column.value.array(),
column.value.position() + column.value.arrayOffset(),
column.value.remaining());
result.put(name, value);
if (_debug) {
System.out.print("(" + name + "=" + value + ")");
}
}
if (_debug) {
System.out.println();
}
return Ok;
} catch (Exception e) {
errorexception = e;
}
try {
Thread.sleep(500);
} catch (InterruptedException e) {
}
}
errorexception.printStackTrace();
errorexception.printStackTrace(System.out);
return Error;
}