HBase API客户端操作

1、创建Maven工程，添加依赖

<dependencies>
    <dependency>
        <groupId>org.apache.hbase</groupId>
        <artifactId>hbase-client</artifactId>
        <version>1.3.1</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.testng</groupId>
        <artifactId>testng</artifactId>
        <version>6.14.3</version>
        <scope>test</scope>
    </dependency>
</dependencies>

2、建立HBase的连接与释放

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.*;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;

public class HbaseClientDemo {
    Configuration conf = null;
    Connection conn = null;

    @Before
    public void init() throws IOException {
        //获取一个配置文件对象
        conf = HBaseConfiguration.create();

        conf.set("hbase.zookeeper.quorum", "linux121,linux122");
        conf.set("hbase.zookeeper.property.clientPort", "2181");
        //通过conf获取到hbase集群的连接
        conn = ConnectionFactory.createConnection(conf);
    }

    // 等下进行操作的代码，写在这里    

    //释放连接
    @After
    public void realse() {
        if (conn != null) {
            try {
                conn.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

3、创建表：

 //创建一张hbase表
    @Test
    public void createTable() throws IOException {
        //获取HbaseAdmin对象用来创建表
        HBaseAdmin admin = (HBaseAdmin) conn.getAdmin();
        //创建Htabledesc描述器，表描述器
        final HTableDescriptor worker = new HTableDescriptor(TableName.valueOf("worker"));
        //指定列族
        worker.addFamily(new HColumnDescriptor("info"));
        admin.createTable(worker);
        System.out.println("worker表创建成功！！");
    }

4、插入数据

 //插入一条数据
    @Test
    public void putData() throws IOException {
        //需要获取一个table对象
        final Table worker = conn.getTable(TableName.valueOf("worker"));

        //准备put对象
        final Put put = new Put(Bytes.toBytes("110"));//指定rowkey

        put.addColumn(Bytes.toBytes("info"), Bytes.toBytes("addr"), Bytes.toBytes("beijing"));
        //插入数据，参数类型是put
        worker.put(put);
        //准备list<puts>,可以执行批量插入
        //关闭table对象
        worker.close();
        System.out.println("插入数据到worker表成功！！");
    }

5、删除数据：

//删除一条数据
    @Test
    public void deleteData() throws IOException {
        //需要获取一个table对象
        final Table worker = conn.getTable(TableName.valueOf("worker"));

        //准备delete对象
        final Delete delete = new Delete(Bytes.toBytes("110"));
    //执行删除
        worker.delete(delete);
        //关闭table对象
        worker.close();
        System.out.println("删除数据成功！！");
    }

6、查询某个列族数据

//查询数据
    @Test
    public void getData() throws IOException {
        //准备table对象
        final Table worker = conn.getTable(TableName.valueOf("worker"));
        //准备get对象
        final Get get = new Get(Bytes.toBytes("110"));
        //指定查询某个列族或者列
        get.addFamily(Bytes.toBytes("info"));
        //执行查询
        final Result result = worker.get(get);
        //获取到result中所有cell对象
        final Cell[] cells = result.rawCells();
        //遍历打印
        for (Cell cell : cells) {
            final String rowkey = Bytes.toString(CellUtil.cloneRow(cell));
            final String f = Bytes.toString(CellUtil.cloneFamily(cell));
            final String column = Bytes.toString(CellUtil.cloneQualifier(cell));
            final String value = Bytes.toString(CellUtil.cloneValue(cell));

            System.out.println("rowkey-->" + rowkey + "--;cf-->" + f + "---;column--->" + column + "--;value-->" + value);
        }
        worker.close();
    }

7、通过Scan全表扫描

 //全表扫描
    @Test
    public void scanData() throws IOException {
        //准备table对象
        final Table worker = conn.getTable(TableName.valueOf("worker"));
        //准备scan对象
        final Scan scan = new Scan();

        //执行扫描
        final ResultScanner resultScanner = worker.getScanner(scan);
        for (Result result : resultScanner) {
            //获取到result中所有cell对象
            final Cell[] cells = result.rawCells();
            //遍历打印
            for (Cell cell : cells) {
                final String rowkey = Bytes.toString(CellUtil.cloneRow(cell));
                final String f = Bytes.toString(CellUtil.cloneFamily(cell));
                final String column = Bytes.toString(CellUtil.cloneQualifier(cell));
                final String value = Bytes.toString(CellUtil.cloneValue(cell));
                System.out.println("rowkey-->" + rowkey + "--;cf-->" + f + ";column--->" + column + "--;value-->" + value);
            }
        }

        worker.close();
    }

8、通过startRowKey和endRowKey进行扫描

//指定scan 开始rowkey和结束rowkey，这种查询方式建议使用，指定开始和结束rowkey区间避免全表扫描
@Test
public void scanStartEndData() throws IOException {
    //准备table对象
    final Table worker = conn.getTable(TableName.valueOf("worker"));
    //准备scan对象
    final Scan scan = new Scan();
    //指定查询的rowkey区间,rowkey在hbase中是以字典序排序
    scan.setStartRow(Bytes.toBytes("001"));
    scan.setStopRow(Bytes.toBytes("004"));
    //执行扫描
    final ResultScanner resultScanner = worker.getScanner(scan);
    for (Result result : resultScanner) {
        //获取到result中所有cell对象
        final Cell[] cells = result.rawCells();
        //遍历打印
        for (Cell cell : cells) {
            final String rowkey = Bytes.toString(CellUtil.cloneRow(cell));
            final String f = Bytes.toString(CellUtil.cloneFamily(cell));
            final String column = Bytes.toString(CellUtil.cloneQualifier(cell));
            final String value = Bytes.toString(CellUtil.cloneValue(cell));
            System.out.println("rowkey-->" + rowkey + "--;cf-->" + f + ";column--->" + column + "--;value-->" + value);
        }
    }

    worker.close();
}