Hbase的Java操作

HBase Java API
1 导入pom依赖
        <dependency>
            <groupId>org.apache.hbase</groupId>
            <artifactId>hbase-client</artifactId>
            <version>1.3.1</version>
        </dependency>
2 添加配置文件
在resource目录下创建hbase-site.xml


<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<configuration>
    <property>
        <name>hbase.zookeeper.quorum</name>
        <value>zk01,zk02,zk03</value>
        <description>The directory shared by region servers.
        </description>
    </property>
</configuration>
3 连接Hbase

//  hbase的两种连接方式：1）读取配置文件 只需要配置zookeeper 
        Configuration config = HBaseConfiguration.create();
        Connection connection = ConnectionFactory.createConnection(config);
//2）通过代码配置
        Configuration configuration = new Configuration();
        configuration.set("hbase.zookeeper.quorum", "zk01:2181,zk02:2181,zk03:2181");
        connection = ConnectionFactory.createConnection();
4 创建表

 public static void main(String[] args) throws IOException {
        // 1.连接HBase
        // 1.1 HBaseConfiguration.create(); 
        Configuration config = HBaseConfiguration.create();
        // 1.2 创建一个连接
        Connection connection = ConnectionFactory.createConnection(config);
        // 1.3 从连接中获得一个Admin对象
        Admin admin = connection.getAdmin();
        // 2.创建表
        // 2.1 判断表是否存在
        TableName tableName = TableName.valueOf("user");
        if (!admin.tableExists(tableName)) {
            //2.2 如果表不存在就创建一个表
            HTableDescriptor hTableDescriptor = new HTableDescriptor(tableName);
            hTableDescriptor.addFamily(new HColumnDescriptor("base_info"));
            admin.createTable(hTableDescriptor);
            System.out.println("创建表");
        }
    }
5 打印表的信息

@Before
public void initConnection() {
        try {
            connection = ConnectionFactory.createConnection(config);
        } catch (IOException e) {
            System.out.println("连接数据库失败");
        }
}
​
@Test 
public void tableInfo() throws IOException {
        // 1.定义表的名称
        TableName tableName = TableName.valueOf("user");
        // 2.获取表
        Table table = connection.getTable(tableName);
        // 3.获取表的描述信息
        HTableDescriptor tableDescriptor = table.getTableDescriptor();
        // 4.获取表的列簇信息
        HColumnDescriptor[] columnFamilies = tableDescriptor.getColumnFamilies();
        for (HColumnDescriptor columnFamily : columnFamilies) {
            // 5.获取表的columFamily的字节数组
            byte[] name = columnFamily.getName();
            // 6.使用hbase自带的bytes工具类转成string
            String value = Bytes.toString(name);
            // 7.打印
            System.out.println(value);
        }
    }
6 添加数据(PUT)



@Before
public void initConnection() {
        try {
            connection = ConnectionFactory.createConnection(config);
        } catch (IOException e) {
            System.out.println("连接数据库失败");
        }
}
@Test
public void put() throws IOException {
        // 1.定义表的名称
        TableName tableName = TableName.valueOf("user");
        // 2.获取表
        Table table = connection.getTable(tableName);
        // 3.准备数据
        String rowKey = "rowkey_10";
        Put zhangsan = new Put(Bytes.toBytes(rowKey));
        zhangsan.addColumn(Bytes.toBytes("base_info"), Bytes.toBytes("username"), Bytes.toBytes("张三"));
        zhangsan.addColumn(Bytes.toBytes("base_info"), Bytes.toBytes("sex"), Bytes.toBytes("1"));
        zhangsan.addColumn(Bytes.toBytes("base_info"), Bytes.toBytes("address"), Bytes.toBytes("北京市"));
        zhangsan.addColumn(Bytes.toBytes("base_info"), Bytes.toBytes("birthday"), Bytes.toBytes("2014-07-10"));
        // 4. 添加数据
        table.put(zhangsan);
        table.close();
}
7 获取数据(Get)
 @Test
public void get() throws IOException {
        // 1.定义表的名称
        TableName tableName = TableName.valueOf("user");
        // 2.获取表
        Table table = connection.getTable(tableName);
        // 3.准备数据
        String rowKey = "rowkey_10";
        // 4.拼装查询条件
        Get get = new Get(Bytes.toBytes(rowKey));
        // 5.查询数据
        Result result = table.get(get);
        // 6.打印数据 获取所有的单元格
        List<Cell> cells = result.listCells();
        for (Cell cell : cells) {
            // 打印rowkey,family,qualifier,value
            System.out.println(Bytes.toString(CellUtil.cloneRow(cell))
                    + "==> " + Bytes.toString(CellUtil.cloneFamily(cell))
                    + "{" + Bytes.toString(CellUtil.cloneQualifier(cell))
                    + ":" + Bytes.toString(CellUtil.cloneValue(cell)) + "}");
        }
}
　　



8 全表扫描（scan 慎用）
@Test
public void scan() throws IOException {
        // 1.定义表的名称
        TableName tableName = TableName.valueOf("user");
        // 2.获取表
        Table table = connection.getTable(tableName);
        // 3.全表扫描
        Scan scan = new Scan();
        // 4.获取扫描结果
        ResultScanner scanner = table.getScanner(scan);
        Result result = null;
        // 5. 迭代数据
        while ((result = scanner.next()) != null) {
            // 6.打印数据 获取所有的单元格
            List<Cell> cells = result.listCells();
            for (Cell cell : cells) {
                // 打印rowkey,family,qualifier,value
                System.out.println(Bytes.toString(CellUtil.cloneRow(cell))
                        + "==> " + Bytes.toString(CellUtil.cloneFamily(cell))
                        + "{" + Bytes.toString(CellUtil.cloneQualifier(cell))
                        + ":" + Bytes.toString(CellUtil.cloneValue(cell)) + "}");
            }
        }
}