标签:style blog io os ar 使用 java for sp
针对的时Cassandra 2.0 数据库
Java本地客户端访问Cassandra,首先建立Java工程,使用Maven进行管理。
引入依赖:
<dependency>
<groupId>com.datastax.cassandra</groupId>
<artifactId>cassandra-driver-core</artifactId>
<version>2.1.0</version>
</dependency>Cluster cluster = Cluster.builder()
.addContactPoint("your ip")
.build();
Metadata metadata = cluster.getMetadata();
System.out.printf("Connected to cluster: %s\n",
metadata.getClusterName());
for (Host host : metadata.getAllHosts()) {
System.out.printf("Datatacenter: %s; Host: %s; Rack: %s\n",
host.getDatacenter(), host.getAddress(), host.getRack());
}Session session = cluster.connect();
3. 通过Session对象实现所有的DML等操作。 (PS:在对 Cassandra 进行操作之前,建议先了解 Cassandra 的架构以及数据组织形式)
a. 我们首先建立一个Schema:
<pre name="code" class="java">ResultSet results = session.execute("SELECT * FROM simplex.playlists ");
System.out.println(String.format("%-30s\t%-20s\t%-20s\n%s", "title", "album", "artist",
"-------------------------------+-----------------------+--------------------"));
for (Row row : results) {
System.out.println(String.format("%-30s\t%-20s\t%-20s", row.getString("title"),
row.getString("album"), row.getString("artist")));
}
System.out.println();session.execute(
"CREATE TABLE simplex.songs (" +
"id uuid PRIMARY KEY," +
"title text," +
"album text," +
"artist text," +
"tags set<text>," +
"data blob" +
");"); c. 插入数据:
session.execute(
"INSERT INTO simplex.songs (id, title, album, artist, tags) " +
"VALUES (" +
"756716f7-2e54-4715-9f00-91dcbea6cf50," +
"'La Petite Tonkinoise'," +
"'Bye Bye Blackbird'," +
"'Joséphine Baker'," +
"{'jazz', '2013'})" +
";"); d. 查询数据:
ResultSet results = session.execute("SELECT * FROM simplex.playlists ");
System.out.println(String.format("%-30s\t%-20s\t%-20s\n%s", "title", "album", "artist",
"-------------------------------+-----------------------+--------------------"));
for (Row row : results) {
System.out.println(String.format("%-30s\t%-20s\t%-20s", row.getString("title"),
row.getString("album"), row.getString("artist")));
}
System.out.println();标签:style blog io os ar 使用 java for sp
原文地址:http://blog.csdn.net/zhuyu_deng/article/details/40430713