HBASE08

第 4 章 HBase API

4.1 环境准备

新建项目后在 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>

4.2 HBaseAPI

4.2.1 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", "192.166.9.102");

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

}

4.2.2 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);

}

4.2.3 创建表

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！");

}

}

4.2.4 删除表

public static void dropTable(String tableName) throws

MasterNotRunningException,

ZooKeeperConnectionException, IOException{

HBaseAdmin admin = new HBaseAdmin(conf);

if(isTableExist(tableName)){

admin.disableTable(tableName);

admin.deleteTable(tableName);

System.out.println("表" + tableName + "删除成功！");

}else{

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

}

}

4.2.5 向表中插入数据

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");

}