每日总结

HBase API

（1）pom.xml 中添加依赖：

<dependency>

<groupId>org.apache.hbase</groupId>

<artifactId>hbase-server</artifactId>

<version>1.3.1</version>

</dependency>

<dependency>

<groupId>org.apache.hbase</groupId>

<artifactId>hbase-client</artifactId>

<version>1.3.1</version>

</dependency>

（2）获取 Configuration 对象

public static Configuration conf;

static{

//使用 HBaseConfiguration 的单例方法实例化

conf = HBaseConfiguration.create();

conf.set("hbase.zookeeper.quorum", "192.168.10.102");

conf.set("hbase.zookeeper.property.clientPort", "2181");

}

（3）判断表是否存在

public static boolean isTableExist(String tableName) throws

MasterNotRunningException,

ZooKeeperConnectionException, IOException{

//在 HBase 中管理、访问表需要先创建 HBaseAdmin 对象

//Connection connection =

ConnectionFactory.createConnection(conf);

//HBaseAdmin admin = (HBaseAdmin) connection.getAdmin();

HBaseAdmin admin = new HBaseAdmin(conf);

return admin.tableExists(tableName);

}

（4）创建表

v>

public static void createTable(String tableName, String...

columnFamily) throws

MasterNotRunningException, ZooKeeperConnectionException,

IOException{

HBaseAdmin admin = new HBaseAdmin(conf);

//判断表是否存在

if(isTableExist(tableName)){

System.out.println("表" + tableName + "已存在");

//System.exit(0);

}else{

//创建表属性对象,表名需要转字节

HTableDescriptor descriptor =

new

HTableDescriptor(TableName.valueOf(tableName));

//创建多个列族

for(String cf : columnFamily){

descriptor.addFamily(new HColumnDescriptor(cf));

}

//根据对表的配置，创建表

admin.createTable(descriptor);

System.out.println("表" + tableName + "创建成功！");

}

}

（5）向表中插入数据

v>

public static void addRowData(String tableName, String rowKey,

String columnFamily, String

column, String value) throws IOException{

//创建 HTable 对象

HTable hTable = new HTable(conf, tableName);

//向表中插入数据

Put put = new Put(Bytes.toBytes(rowKey));

//向 Put 对象中组装数据

put.add(Bytes.toBytes(columnFamily), Bytes.toBytes(column),

Bytes.toBytes(value));

hTable.put(put);

hTable.close();

System.out.println("插入数据成功");

}

（6）获取所有数据

v>

public static void getAllRows(String tableName) throws IOException{

HTable hTable = new HTable(conf, tableName);

//得到用于扫描 region 的对象

Scan scan = new Scan();

//使用 HTable 得到 resultcanner 实现类的对象

ResultScanner resultScanner = hTable.getScanner(scan);

for(Result result : resultScanner){

Cell[] cells = result.rawCells();

for(Cell cell : cells){

//得到 rowkey

System.out.println("

行 键

:"

+

Bytes.toString(CellUtil.cloneRow(cell)));

//得到列族

System.out.println("

列 族

" +

Bytes.toString(CellUtil.cloneFamily(cell)));

System.out.println("

列

:" +

Bytes.toString(CellUtil.cloneQualifier(cell)));

System.out.println("

值

:" +

Bytes.toString(CellUtil.cloneValue(cell)));

}

}

}