---
title: Cassandra0.7.0のJava APIサンプル
tags: []
categories: ["Middleware", "NoSQL", "Cassandra"]
date: 2010-12-23T18:48:59Z
updated: 2011-01-13T15:26:13Z
---

動作確認バージョンはサーバ・クライアントともに`0.7.0`。**(2010/01/12更新)**

## pom.xml

クライアントライブラリの依存関係はMavenでさっくり解決しちゃいましょう。

    <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
        <groupId>ik.am</groupId>
        <artifactId>cassandra-sample</artifactId>
        <version>1.0.0-SNAPSHOT</version>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <configuration>
                        <source>1.6</source>
                        <target>1.6</target>
                        <encoding>UTF-8</encoding>
                    </configuration>
                </plugin>
            </plugins>
        </build>
        <repositories>
            <repository>
                <id>riptano</id>
                <url>http://mvn.riptano.com/content/repositories/public/</url>
            </repository>
        </repositories>
        <dependencies>
            <dependency>
                <groupId>org.apache.cassandra</groupId>
                <artifactId>apache-cassandra</artifactId>
                <version>0.7.0</version>
            </dependency>
        </dependencies>
    </project>

で

    $ mvn eclipse:eclipse -DdownloadSources=true

## API

データは[前回の記事][1]同様。

    [default@demo] list users;
    Using default limit of 100
    -------------------
    RowKey: nobunaga
    => (column=birth_date, value=1534, timestamp=1293042940549000)
    => (column=blood, value=A, timestamp=1293042957506000)
    => (column=full_name, value=Nobunaga Oda, timestamp=1293042893235000)
    -------------------
    RowKey: making
    => (column=birth_date, value=1984, timestamp=1293042776114000)
    => (column=blood, value=B, timestamp=1293042734033000)
    => (column=full_name, value=Toshiaki Maki, timestamp=1293042756442000)
    -------------------
    RowKey: hideyoshi
    => (column=birth_date, value=1537, timestamp=1293042846014000)
    => (column=blood, value=A, timestamp=1293042867208000)
    => (column=full_name, value=Hideyoshi Toyotomi, timestamp=1293042812951000)

### 1列から特定のカラムのみ取得

    import java.io.UnsupportedEncodingException;
    import java.nio.ByteBuffer;
    
    import org.apache.cassandra.thrift.Cassandra;
    import org.apache.cassandra.thrift.Column;
    import org.apache.cassandra.thrift.ColumnOrSuperColumn;
    import org.apache.cassandra.thrift.ColumnPath;
    import org.apache.cassandra.thrift.ConsistencyLevel;
    import org.apache.thrift.protocol.TBinaryProtocol;
    import org.apache.thrift.protocol.TProtocol;
    import org.apache.thrift.transport.TFramedTransport;
    import org.apache.thrift.transport.TSocket;
    import org.apache.thrift.transport.TTransport;
    
    public class Main {
        public static final String CHARSET = "UTF-8";
    
        public static void main(String[] args) throws Exception {
            TTransport transport = new TSocket("localhost", 9160);
            TFramedTransport tf = new TFramedTransport(transport);
            TProtocol proto = new TBinaryProtocol(tf);
            Cassandra.Client client = new Cassandra.Client(proto);
    
            transport.open();
    
            try {
                // キースペース名
                String ksName = "demo";
                // カラムファミリ名
                String cfName = "users";
                // キー名
                String keyName = "making";
                // カラム名
                String cName = "full_name";
    
                client.set_keyspace(ksName);
                ByteBuffer key = buffer(keyName);
    
                ColumnPath path = new ColumnPath(cfName);
                path.setColumn(buffer(cName));
    
                ColumnOrSuperColumn cosc = client.get(key, path,
                        ConsistencyLevel.ONE);
                Column column = cosc.getColumn();
                System.out.println(new String(column.getName(), CHARSET)); // -> full_name
                System.out.println(new String(column.getValue(), CHARSET)); // -> Toshiaki Maki
            } finally {
                transport.close();
            }
        }
    
        public static ByteBuffer buffer(String value)
                throws UnsupportedEncodingException {
            return ByteBuffer.wrap(value.getBytes(CHARSET));
        }
    }

### 1列から任意指定したカラムを取得

`SlicePredicate`に取得したいカラム名リストを設定。

    import java.io.UnsupportedEncodingException;
    import java.nio.ByteBuffer;
    import java.util.Arrays;
    import java.util.List;

    import org.apache.cassandra.thrift.Cassandra;
    import org.apache.cassandra.thrift.Column;
    import org.apache.cassandra.thrift.ColumnOrSuperColumn;
    import org.apache.cassandra.thrift.ColumnParent;
    import org.apache.cassandra.thrift.ConsistencyLevel;
    import org.apache.cassandra.thrift.SlicePredicate;
    import org.apache.thrift.protocol.TBinaryProtocol;
    import org.apache.thrift.protocol.TProtocol;
    import org.apache.thrift.transport.TFramedTransport;
    import org.apache.thrift.transport.TSocket;
    import org.apache.thrift.transport.TTransport;

    public class Main2 {
        public static final String CHARSET = "UTF-8";

        public static void main(String[] args) throws Exception {
            TTransport transport = new TSocket("localhost", 9160);
            TFramedTransport tf = new TFramedTransport(transport);
            TProtocol proto = new TBinaryProtocol(tf);
            Cassandra.Client client = new Cassandra.Client(proto);

            transport.open();

            try {
                // キースペース名
                String ksName = "demo";
                // カラムファミリ名
                String cfName = "users";
                // キー名
                String keyName = "making";

                client.set_keyspace(ksName);
                ByteBuffer key = buffer(keyName);

                SlicePredicate predicate = new SlicePredicate();
                // 取得したいカラム名をリストで渡す
                predicate.setColumn_names(Arrays.asList(buffer("full_name"),
                        buffer("blood")));
                ColumnParent parent = new ColumnParent(cfName);
                List<ColumnOrSuperColumn> results = client.get_slice(key, parent,
                        predicate, ConsistencyLevel.ONE);
                System.out.println("----------");
                for (ColumnOrSuperColumn cosc : results) {
                    Column column = cosc.getColumn();
                    System.out.println(new String(column.getName(), CHARSET));
                    System.out.println(new String(column.getValue(), CHARSET));
                    System.out.println("----------");
                }
            } finally {
                transport.close();
            }
        }

        public static ByteBuffer buffer(String value)
                throws UnsupportedEncodingException {
            return ByteBuffer.wrap(value.getBytes(CHARSET));
        }
    }

出力結果

    ----------
    blood
    B
    ----------
    full_name
    Toshiaki Maki
    ----------


### 1列から範囲指定したカラムを取得

`SlicePredicate`に`SliceRange`を設定。

    import java.io.UnsupportedEncodingException;
    import java.nio.ByteBuffer;
    import java.util.List;
    
    import org.apache.cassandra.thrift.Cassandra;
    import org.apache.cassandra.thrift.Column;
    import org.apache.cassandra.thrift.ColumnOrSuperColumn;
    import org.apache.cassandra.thrift.ColumnParent;
    import org.apache.cassandra.thrift.ConsistencyLevel;
    import org.apache.cassandra.thrift.SlicePredicate;
    import org.apache.cassandra.thrift.SliceRange;
    import org.apache.thrift.protocol.TBinaryProtocol;
    import org.apache.thrift.protocol.TProtocol;
    import org.apache.thrift.transport.TFramedTransport;
    import org.apache.thrift.transport.TSocket;
    import org.apache.thrift.transport.TTransport;
    
    public class Main3 {
        public static final String CHARSET = "UTF-8";
    
        public static void main(String[] args) throws Exception {
            TTransport transport = new TSocket("localhost", 9160);
            TFramedTransport tf = new TFramedTransport(transport);
            TProtocol proto = new TBinaryProtocol(tf);
            Cassandra.Client client = new Cassandra.Client(proto);
    
            transport.open();
    
            try {
                // キースペース名
                String ksName = "demo";
                // カラムファミリ名
                String cfName = "users";
                // キー名
                String keyName = "making";
    
                client.set_keyspace(ksName);
                ByteBuffer key = buffer(keyName);
    
                SlicePredicate predicate = new SlicePredicate();
                SliceRange sliceRange = new SliceRange();
                sliceRange.setStart(buffer("birth_date"));
                sliceRange.setFinish(buffer("full_name"));
                predicate.setSlice_range(sliceRange);
    
                ColumnParent parent = new ColumnParent(cfName);
                List<ColumnOrSuperColumn> results = client.get_slice(key, parent,
                        predicate, ConsistencyLevel.ONE);
                System.out.println("----------");
                for (ColumnOrSuperColumn cosc : results) {
                    Column column = cosc.getColumn();
                    System.out.println(new String(column.getName(), CHARSET));
                    System.out.println(new String(column.getValue(), CHARSET));
                    System.out.println("----------");
    
                }
            } finally {
                transport.close();
            }
        }
    
        public static ByteBuffer buffer(String value)
                throws UnsupportedEncodingException {
            return ByteBuffer.wrap(value.getBytes(CHARSET));
        }
    }

出力結果

    ----------
    birth_date
    (longをStringに変換しようとしているので文字化け...byte[]からどうやって判断するんだっけ)←下に追記（2010/01/11）
    ----------
    blood
    B
    ----------
    full_name
    Toshiaki Maki
    ----------

全カラムを取得したい場合、

    sliceRange.setStart(new byte[0]);
    sliceRange.setFinish(new byte[0]);

のようにする。

#### byte[]からlongに変換（2010/01/11追記）


    public static long readLong(byte[] bytes, int offset) {
        return (((long) (bytes[offset + 0] & 0xff) << 56)
                | ((long) (bytes[offset + 1] & 0xff) << 48)
                | ((long) (bytes[offset + 2] & 0xff) << 40)
                | ((long) (bytes[offset + 3] & 0xff) << 32)
                | ((long) (bytes[offset + 4] & 0xff) << 24)
                | ((long) (bytes[offset + 5] & 0xff) << 16)
                | ((long) (bytes[offset + 6] & 0xff) << 8) | ((long) bytes[offset + 7] & 0xff));
    }

    public static long readLong(byte[] bytes) {
        return readLong(bytes, 0);
    }

↑のメソッドを呼び出せば良い。ただし、どのカラムがどの型であるかはわからない。。カラム名と型のマップが必要なのかな。。。？



### 範囲指定した列から任意指定したカラムの値を取得する

今度は`get_range_slices`メソッド。

    import java.io.UnsupportedEncodingException;
    import java.nio.ByteBuffer;
    import java.util.Arrays;
    import java.util.List;
    
    import org.apache.cassandra.thrift.Cassandra;
    import org.apache.cassandra.thrift.Column;
    import org.apache.cassandra.thrift.ColumnOrSuperColumn;
    import org.apache.cassandra.thrift.ColumnParent;
    import org.apache.cassandra.thrift.ConsistencyLevel;
    import org.apache.cassandra.thrift.KeyRange;
    import org.apache.cassandra.thrift.KeySlice;
    import org.apache.cassandra.thrift.SlicePredicate;
    import org.apache.thrift.protocol.TBinaryProtocol;
    import org.apache.thrift.protocol.TProtocol;
    import org.apache.thrift.transport.TFramedTransport;
    import org.apache.thrift.transport.TSocket;
    import org.apache.thrift.transport.TTransport;
    
    public class Main4 {
        public static final String CHARSET = "UTF-8";
    
        public static void main(String[] args) throws Exception {
            TTransport transport = new TSocket("localhost", 9160);
            TFramedTransport tf = new TFramedTransport(transport);
            TProtocol proto = new TBinaryProtocol(tf);
            Cassandra.Client client = new Cassandra.Client(proto);
    
            transport.open();
    
            try {
                // キースペース名
                String ksName = "demo";
                // カラムファミリ名
                String cfName = "users";
    
                client.set_keyspace(ksName);
    
                SlicePredicate predicate = new SlicePredicate();
                predicate.setColumn_names(Arrays.asList(buffer("full_name"),
                        buffer("blood")));
    
                KeyRange keyRange = new KeyRange();
                keyRange.setStart_key(buffer("nobunaga"));
                keyRange.setEnd_key(buffer("hideyoshi"));
    
                ColumnParent parent = new ColumnParent(cfName);
    
                List<KeySlice> results = client.get_range_slices(parent, predicate,
                        keyRange, ConsistencyLevel.ONE);
    
                System.out.println("----------");
                for (KeySlice keySlice : results) {
                    List<ColumnOrSuperColumn> coscs = keySlice.getColumns();
                    for (ColumnOrSuperColumn cosc : coscs) {
                        Column column = cosc.getColumn();
                        System.out.printf("%s=%s%n", new String(column.getName(),
                                CHARSET), new String(column.getValue(), CHARSET));
                    }
                    System.out.println("----------");
    
                }
            } finally {
                transport.close();
            }
        }
    
        public static ByteBuffer buffer(String value)
                throws UnsupportedEncodingException {
            return ByteBuffer.wrap(value.getBytes(CHARSET));
        }
    }


出力結果

    ----------
    blood=A
    full_name=Nobunaga Oda
    ----------
    blood=B
    full_name=Toshiaki Maki
    ----------
    blood=A
    full_name=Hideyoshi Toyotomi
    ----------

### 任意指定した複数の列から任意指定したカラムの値を取得する

今度は`multiget_slices`メソッド。結果は`Map`で返ってくる。

    import java.io.UnsupportedEncodingException;
    import java.nio.ByteBuffer;
    import java.util.Arrays;
    import java.util.List;
    import java.util.Map;
    import java.util.Map.Entry;
    
    import org.apache.cassandra.thrift.Cassandra;
    import org.apache.cassandra.thrift.Column;
    import org.apache.cassandra.thrift.ColumnOrSuperColumn;
    import org.apache.cassandra.thrift.ColumnParent;
    import org.apache.cassandra.thrift.ConsistencyLevel;
    import org.apache.cassandra.thrift.SlicePredicate;
    import org.apache.cassandra.utils.ByteBufferUtil;
    import org.apache.thrift.protocol.TBinaryProtocol;
    import org.apache.thrift.protocol.TProtocol;
    import org.apache.thrift.transport.TFramedTransport;
    import org.apache.thrift.transport.TSocket;
    import org.apache.thrift.transport.TTransport;
    
    public class Main5 {
        public static final String CHARSET = "UTF-8";
    
        public static void main(String[] args) throws Exception {
            TTransport transport = new TSocket("localhost", 9160);
            TFramedTransport tf = new TFramedTransport(transport);
            TProtocol proto = new TBinaryProtocol(tf);
            Cassandra.Client client = new Cassandra.Client(proto);
    
            transport.open();
    
            try {
                // キースペース名
                String ksName = "demo";
                // カラムファミリ名
                String cfName = "users";
    
                client.set_keyspace(ksName);
    
                SlicePredicate predicate = new SlicePredicate();
                predicate.setColumn_names(Arrays.asList(buffer("full_name"),
                        buffer("blood")));
    
                List<ByteBuffer> rowKeys = Arrays.asList(buffer("nobunaga"),
                        buffer("hideyoshi"));
    
                ColumnParent parent = new ColumnParent(cfName);
    
                Map<ByteBuffer, List<ColumnOrSuperColumn>> results = client
                        .multiget_slice(rowKeys, parent, predicate,
                                ConsistencyLevel.ONE);
    
                System.out.println("----------");
                for (Entry<ByteBuffer, List<ColumnOrSuperColumn>> e : results
                        .entrySet()) {
                    ByteBuffer key = e.getKey();
                    System.out.println("key="
                            + ByteBufferUtil.string(key, Charset.forName(CHARSET)));
                    List<ColumnOrSuperColumn> coscs = e.getValue();
                    for (ColumnOrSuperColumn cosc : coscs) {
                        Column column = cosc.getColumn();
                        System.out.printf("%s=%s%n", new String(column.getName(),
                                CHARSET), new String(column.getValue(), CHARSET));
                    }
                    System.out.println("----------");
    
                }
            } finally {
                transport.close();
            }
        }
    
        public static ByteBuffer buffer(String value)
                throws UnsupportedEncodingException {
            return ByteBuffer.wrap(value.getBytes(CHARSET));
        }
    }

出力結果


    ----------
    key=hideyoshi
    blood=A
    full_name=Hideyoshi Toyotomi
    ----------
    key=nobunaga
    blood=A
    full_name=Nobunaga Oda
    ----------

<s>`ByteBuffer`なキーからキー値を取得する方法がいまいち分かっていない。</s>

→以下の方法で取得可。(**2011/01/01追加**)

    new String(byteBuffer.array(), byteBuffer.arrayOffset() + byteBuffer.position(), byteBuffer.remaining(), encoding);

→**`org.apache.cassandra.utils.ByteBufferUtil.string(ByteBuffer)`に用意してありました(2011/01/13追加)**

### 1カラムずつデータ挿入

`long` -> `ByteBuffer`の変換は分かりやすさのため、愚直に実装しました。

→**`org.apache.cassandra.utils.FBUtilities.toByteBuffer(long)`に用意してありました。一応残しておきました。(2011/01/13追加)**

    import java.io.UnsupportedEncodingException;
    import java.nio.ByteBuffer;

    import org.apache.cassandra.thrift.Cassandra;
    import org.apache.cassandra.thrift.Column;
    import org.apache.cassandra.thrift.ColumnParent;
    import org.apache.cassandra.thrift.ConsistencyLevel;
    import org.apache.thrift.protocol.TBinaryProtocol;
    import org.apache.thrift.protocol.TProtocol;
    import org.apache.thrift.transport.TFramedTransport;
    import org.apache.thrift.transport.TSocket;
    import org.apache.thrift.transport.TTransport;

    public class Main6 {
        public static final String CHARSET = "UTF-8";

        public static void main(String[] args) throws Exception {
            TTransport transport = new TSocket("localhost", 9160);
            TFramedTransport tf = new TFramedTransport(transport);
            TProtocol proto = new TBinaryProtocol(tf);
            Cassandra.Client client = new Cassandra.Client(proto);

            transport.open();

            // 1カラムにのみデータ挿入するサンプル
            try {
                // キースペース名
                String ksName = "demo";
                // カラムファミリ名
                String cfName = "users";
                // キー名
                String keyName = "hoge";

                client.set_keyspace(ksName);
                ByteBuffer key = buffer(keyName);

                ColumnParent cp = new ColumnParent(cfName);

                ConsistencyLevel cl = ConsistencyLevel.ONE;

                long timestamp = System.currentTimeMillis();
                // 挿入
                client.insert(key, cp, new Column(buffer("full_name"),
                        buffer("Hogeo Hoge"), timestamp), cl);
                client.insert(key, cp, new Column(buffer("birth_date"),
                        buffer(2000L), timestamp), cl);
                client.insert(key, cp, new Column(buffer("blood"), buffer("A"),
                        timestamp), cl);

            } finally {
                transport.close();
            }
        }

        public static ByteBuffer buffer(String value)
                throws UnsupportedEncodingException {
            return ByteBuffer.wrap(value.getBytes(CHARSET));
        }

        public static ByteBuffer buffer(long value) {
            ByteBuffer buffer = ByteBuffer.allocate(8);

            buffer.put(0, (byte) (0xFF & (value >> 56)));
            buffer.put(1, (byte) (0xFF & (value >> 48)));
            buffer.put(2, (byte) (0xFF & (value >> 40)));
            buffer.put(3, (byte) (0xFF & (value >> 32)));
            buffer.put(4, (byte) (0xFF & (value >> 24)));
            buffer.put(5, (byte) (0xFF & (value >> 16)));
            buffer.put(6, (byte) (0xFF & (value >> 8)));
            buffer.put(7, (byte) (0xFF & value));

            return buffer;
        }
    }


CLIで挿入されていることを確認

    [default@demo] list users;
    Using default limit of 100
    -------------------
    RowKey: hoge
    => (column=birth_date, value=2000, timestamp=1294855343031)
    => (column=blood, value=A, timestamp=1294855343033)
    => (column=full_name, value=Hogeo Hoge, timestamp=1294855343024)


### 複数のカラムに複数のデータをバッチで挿入

普通のカラム版。
`batch_mutate`を使用するが、かなり複雑。。。見やすさのために、軽いORマップ風に書きました。
未検証であるが、多分性能は↑より良いはずです。

    import java.io.UnsupportedEncodingException;
    import java.nio.ByteBuffer;
    import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;

    import org.apache.cassandra.thrift.Cassandra;
    import org.apache.cassandra.thrift.Column;
    import org.apache.cassandra.thrift.ColumnOrSuperColumn;
    import org.apache.cassandra.thrift.ConsistencyLevel;
    import org.apache.cassandra.thrift.Mutation;
    import org.apache.cassandra.utils.FBUtilities;
    import org.apache.thrift.protocol.TBinaryProtocol;
    import org.apache.thrift.protocol.TProtocol;
    import org.apache.thrift.transport.TFramedTransport;
    import org.apache.thrift.transport.TSocket;
    import org.apache.thrift.transport.TTransport;

    public class Main7 {
        public static final String CHARSET = "UTF-8";

        public static class User {
            public String key;
            public String fullName;
            public long birthDate;
            public String blood;

            public User(String key, String fullName, long birthDate, String blood) {
                this.key = key;
                this.fullName = fullName;
                this.birthDate = birthDate;
                this.blood = blood;
            }
        }

        private static Mutation mutation(Column column) {
            Mutation mutation = new Mutation();
            ColumnOrSuperColumn cosc = new ColumnOrSuperColumn();
            cosc.setColumn(column);
            mutation.setColumn_or_supercolumn(cosc);
            return mutation;
        }

        private static Map<ByteBuffer, Map<String, List<Mutation>>> createMutaionMap()
                throws Exception {
            // カラムファミリ名
            String cfName = "users";
            Map<ByteBuffer, Map<String, List<Mutation>>> mutaionMap = new HashMap<ByteBuffer, Map<String, List<Mutation>>>();

            User[] users = { new User("xxx", "Taro Yamada", 1999, "O"),
                    new User("yyy", "Ichiro Suzuki", 1990, "AB") };

            long timestamp = System.currentTimeMillis();

            for (User user : users) {
                List<Mutation> columns = new ArrayList<Mutation>();

                columns.add(mutation(new Column(buffer("full_name"),
                        buffer(user.fullName), timestamp)));
                columns.add(mutation(new Column(buffer("birth_date"), FBUtilities
                        .toByteBuffer(user.birthDate), timestamp)));
                columns.add(mutation(new Column(buffer("blood"),
                        buffer(user.blood), timestamp)));

                Map<String, List<Mutation>> innerMap = new HashMap<String, List<Mutation>>();
                innerMap.put(cfName, columns);

                mutaionMap.put(buffer(user.key), innerMap);
            }

            return mutaionMap;
        }

        public static void main(String[] args) throws Exception {
            TTransport transport = new TSocket("localhost", 9160);
            TFramedTransport tf = new TFramedTransport(transport);
            TProtocol proto = new TBinaryProtocol(tf);
            Cassandra.Client client = new Cassandra.Client(proto);

            transport.open();

            // 1カラムにのみデータ挿入するサンプル
            try {
                // キースペース名
                String ksName = "demo";

                client.set_keyspace(ksName);

                Map<ByteBuffer, Map<String, List<Mutation>>> mutationMap = createMutaionMap();

                // バッチ挿入
                client.batch_mutate(mutationMap, ConsistencyLevel.ONE);
            } finally {
                transport.close();
            }
        }

        public static ByteBuffer buffer(String value)
                throws UnsupportedEncodingException {
            return ByteBuffer.wrap(value.getBytes(CHARSET));
        }
    }


一応、確認


    [default@demo] list users;
    Using default limit of 100
    -------------------
    RowKey: xxx
    => (column=birth_date, value=1999, timestamp=1294931407358)
    => (column=blood, value=O, timestamp=1294931407358)
    => (column=full_name, value=Taro Yamada, timestamp=1294931407358)
    -------------------
    RowKey: yyy
    => (column=birth_date, value=1990, timestamp=1294931407358)
    => (column=blood, value=AB, timestamp=1294931407358)
    => (column=full_name, value=Ichiro Suzuki, timestamp=1294931407358)
    -------------------

### バッチ挿入(スーパーカラム使用版)

スーパーカラム版。より面倒。

あとで

### 1列削除

    import java.io.UnsupportedEncodingException;
    import java.nio.ByteBuffer;

    import org.apache.cassandra.thrift.Cassandra;
    import org.apache.cassandra.thrift.ColumnPath;
    import org.apache.cassandra.thrift.ConsistencyLevel;
    import org.apache.thrift.protocol.TBinaryProtocol;
    import org.apache.thrift.protocol.TProtocol;
    import org.apache.thrift.transport.TFramedTransport;
    import org.apache.thrift.transport.TSocket;
    import org.apache.thrift.transport.TTransport;

    public class Main8 {
        public static final String CHARSET = "UTF-8";

        public static void main(String[] args) throws Exception {
            TTransport transport = new TSocket("localhost", 9160);
            TFramedTransport tf = new TFramedTransport(transport);
            TProtocol proto = new TBinaryProtocol(tf);
            Cassandra.Client client = new Cassandra.Client(proto);

            transport.open();

            // 1カラムにのみデータ挿入するサンプル
            try {
                // キースペース名
                String ksName = "demo";
                // カラムファミリ名
                String cfName = "users";
                // キー名
                String keyName = "xxx";

                client.set_keyspace(ksName);
                ByteBuffer key = buffer(keyName);

                ColumnPath cp = new ColumnPath(cfName);

                ConsistencyLevel cl = ConsistencyLevel.ONE;

                long timestamp = System.currentTimeMillis();
                // 削除
                client.remove(key, cp, timestamp, cl);
            } finally {
                transport.close();
            }
        }

        public static ByteBuffer buffer(String value)
                throws UnsupportedEncodingException {
            return ByteBuffer.wrap(value.getBytes(CHARSET));
        }
    }


キーは残るのかな？

    [default@demo] list users;
    Using default limit of 100
    -------------------
    RowKey: xxx
    -------------------
    RowKey: yyy
    => (column=birth_date, value=1990, timestamp=1294931407358)
    => (column=blood, value=AB, timestamp=1294931407358)
    => (column=full_name, value=Ichiro Suzuki, timestamp=1294931407358)
    -------------------

### セカンダリインデックスを指定して検索

[こちら][2]に記載。



----------



`org.apache.cassandra.utils.ByteBufferUtil`、`org.apache.cassandra.utils.FBUtilities`に色々揃ってますな。
`byte[]`→`long`がないけど、、

<div class="amazlet-box" style="margin-bottom:0px;"><div class="amazlet-image" style="float:left;margin:0px 12px 1px 0px;"><a href="http://www.amazon.co.jp/exec/obidos/ASIN/1449390412/ikam-22/ref=nosim/" name="amazletlink" target="_blank"><img src="http://ecx.images-amazon.com/images/I/41eD0bH4XiL._SL160_.jpg" alt="Cassandra: The Definitive Guide" style="border: none;" /></a></div><div class="amazlet-info" style="line-height:120%; margin-bottom: 10px"><div class="amazlet-name" style="margin-bottom:10px;line-height:120%"><a href="http://www.amazon.co.jp/exec/obidos/ASIN/1449390412/ikam-22/ref=nosim/" name="amazletlink" target="_blank">Cassandra: The Definitive Guide</a><div class="amazlet-powered-date" style="font-size:80%;margin-top:5px;line-height:120%">posted with <a href="http://www.amazlet.com/browse/ASIN/1449390412/ikam-22/ref=nosim/" title="Cassandra: The Definitive Guide" target="_blank">amazlet</a> at 10.12.23</div></div><div class="amazlet-detail">Eben Hewitt <br />Oreilly & Associates Inc <br />売り上げランキング: 20382<br /></div><div class="amazlet-sub-info" style="float: left;"><div class="amazlet-link" style="margin-top: 5px"><a href="http://www.amazon.co.jp/exec/obidos/ASIN/1449390412/ikam-22/ref=nosim/" name="amazletlink" target="_blank">Amazon.co.jp で詳細を見る</a></div></div></div><div class="amazlet-footer" style="clear: left"></div></div>


  [1]: http://blog.ik.am/entry/view/id/51/title/Cassandra0.7.0%28-rc2%29%E3%81%AESecondary+indexes%E3%82%92%E8%A9%A6%E3%81%99/
  [2]: http://blog.ik.am/entry/view/id/55/title/Cassandra0.7.0%E3%81%AESecondary+indexes%E3%82%92%E4%BD%BF%E7%94%A8%E3%81%97%E3%81%9FJava+API%E3%82%B5%E3%83%B3%E3%83%97%E3%83%AB/