HBase 开发：使用Java操作HBase

1、实战简介

HBase和Hadoop一样，都是用Java进行开发的，本次实训我们就来学习如何使用Java编写代码来操作HBase数据库。

复制代码

实验环境：
hadoop-2.7
JDK8.0
HBase2.1.1

2、任务

1、第1关：创建表

java 复制代码

package step1;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Admin;
import org.apache.hadoop.hbase.client.ColumnFamilyDescriptor;
import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.client.TableDescriptor;
import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
import org.apache.hadoop.hbase.util.Bytes;
/**
* HBase 1.0 version of ExampleClient that uses {@code Connection},
* {@code Admin} and {@code Table}.
*/
public class Task{
public void createTable()throws Exception{
/********* Begin *********/
Configuration config = HBaseConfiguration.create();
Connection connection = ConnectionFactory.createConnection(config);
try {
// Create table
Admin admin = connection.getAdmin();
try {
TableName tableName = TableName.valueOf("dept");
// 新 API 构建表
// TableDescriptor 对象通过 TableDescriptorBuilder 构建；
TableDescriptorBuilder tableDescriptor =
TableDescriptorBuilder.newBuilder(tableName);
ColumnFamilyDescriptor family =
ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes("data")).build();// 构建列族对象
tableDescriptor.setColumnFamily(family); // 设置列族
admin.createTable(tableDescriptor.build()); // 创建表


TableName emp = TableName.valueOf("emp");
// 新 API 构建表
// TableDescriptor 对象通过 TableDescriptorBuilder 构建；
TableDescriptorBuilder empDescriptor =
TableDescriptorBuilder.newBuilder(emp);
ColumnFamilyDescriptor empfamily =
ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes("emp")).build();// 构建列族对象
empDescriptor.setColumnFamily(empfamily); // 设置列族
admin.createTable(empDescriptor.build()); // 创建表
} finally {
admin.close();
}
} finally {
connection.close();
}
/********* End *********/
}
}

java 复制代码

命令行：

start-dfs.sh （ Hadoop 启动）
回车
start-hbase.sh （ hbase 启动）

2、第2关：添加数据

java 复制代码

package step2;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Admin;
import org.apache.hadoop.hbase.client.ColumnFamilyDescriptor;
import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.client.TableDescriptor;
import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
import org.apache.hadoop.hbase.util.Bytes;
public class Task {
 public void insertInfo()throws Exception{
 /********* Begin *********/
 Configuration config = HBaseConfiguration.create();
 Connection connection = ConnectionFactory.createConnection(config);
 Admin admin = connection.getAdmin();
 TableName tableName = TableName.valueOf("tb_step2");
 TableDescriptorBuilder tableDescriptor = TableDescriptorBuilder.newBuilder(tableName);
 ColumnFamilyDescriptor family = ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes("data")).build();//  构建列族对象
 tableDescriptor.setColumnFamily(family); //  设置列族
 admin.createTable(tableDescriptor.build()); //  创建表
 // 添加数据
 byte[] row1 = Bytes.toBytes("row1");
 Put put1 = new Put(row1); 
 byte[] columnFamily1 = Bytes.toBytes("data"); // 列
 byte[] qualifier1 = Bytes.toBytes(String.valueOf(1)); // 列族修饰词
 byte[] value1 = Bytes.toBytes("张三丰"); // 值
 put1.addColumn(columnFamily1, qualifier1, value1);
 byte[] row2 = Bytes.toBytes("row2");
 Put put2 = new Put(row2); 
 byte[] columnFamily2 = Bytes.toBytes("data"); // 列
 byte[] qualifier2 = Bytes.toBytes(String.valueOf(2)); // 列族修饰词
 byte[] value2 = Bytes.toBytes("张无忌"); // 值
 put2.addColumn(columnFamily2, qualifier2, value2);
 Table table = connection.getTable(tableName);
 table.put(put1);
 table.put(put2);
 /********* End *********/
 }
}

3、第3关：获取数据

java 复制代码

package step3;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Admin;
import org.apache.hadoop.hbase.client.ColumnFamilyDescriptor;
import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.client.TableDescriptor;
import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
import org.apache.hadoop.hbase.util.Bytes;
public class Task {
 public void queryTableInfo()throws Exception{
 /********* Begin *********/
 Configuration config = HBaseConfiguration.create();
 Connection connection = ConnectionFactory.createConnection(config);
 Admin admin = connection.getAdmin();
 TableName tableName = TableName.valueOf("t_step3");
 Table table = connection.getTable(tableName);
 // 获取数据
 Get get = new Get(Bytes.toBytes("row1")); // 定义 get 对象
 Result result = table.get(get); // 通过 table 对象获取数据
 //System.out.println("Result: " + result);
 // 很多时候我们只需要获取"值"   这里表示获取  data:1  列族的值
 byte[] valueBytes = result.getValue(Bytes.toBytes("data"), Bytes.toBytes("1")); // 获取到的是字节数组
 // 将字节转成字符串
 String valueStr = new String(valueBytes,"utf-8");
 System.out.println("value:" + valueStr);
 TableName tableStep3Name = TableName.valueOf("table_step3");
 Table step3Table = connection.getTable(tableStep3Name);
 // 批量查询
 Scan scan = new Scan();
 ResultScanner scanner = step3Table.getScanner(scan);
 try {
 int i = 0;
 for (Result scannerResult: scanner) {
 //byte[] value = scannerResult.getValue(Bytes.toBytes("data"), Bytes.toBytes(1));
 // System.out.println("Scan: " + scannerResult);
 byte[] row = scannerResult.getRow();
 System.out.println("rowName:" + new String(row,"utf-8"));
 }
 } finally {
 scanner.close();
 }
 /********* End *********/
 }
}

4、第4关：删除表

java 复制代码

package step4;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Admin;
import org.apache.hadoop.hbase.client.ColumnFamilyDescriptor;
import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.client.TableDescriptor;
import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
import org.apache.hadoop.hbase.util.Bytes;
public class Task {
 public void deleteTable()throws Exception{
 /********* Begin *********/
 Configuration config = HBaseConfiguration.create();
 Connection connection = ConnectionFactory.createConnection(config);
 Admin admin = connection.getAdmin();
 TableName tableName = TableName.valueOf("t_step4");
 admin.disableTable(tableName);
 admin.deleteTable(tableName);
 /********* End *********/
 }
}