HBase详解(04) - HBase Java API使用

HBase详解(04) - HBase Java API使用

环境准备

新建Maven项目，在pom.xml中添加依赖

<dependency>

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

<artifactId>hbase-server</artifactId>

<version>2.0.5</version>

</dependency>

<dependency>

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

<artifactId>hbase-client</artifactId>

<version>2.0.5</version>

</dependency>

DDL 库表的操作

• 创建HBase_DDL类

package com.zhangjk.HBase;

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.hbase.HBaseConfiguration;

import org.apache.hadoop.hbase.TableName;

import org.apache.hadoop.hbase.client.Admin;

import org.apache.hadoop.hbase.client.Connection;

import org.apache.hadoop.hbase.client.ConnectionFactory;

import org.junit.Test;

import java.io.IOException;

public
class HBase_DDL {

}

• 判断表是否存在

//判断表是否存在

public
static
boolean isTableExist(String tableName)
throws IOException {

//1.创建配置信息并配置

Configuration configuration = HBaseConfiguration.create();

configuration.set("hbase.zookeeper.quorum",
"hadoop102,hadoop103,hadoop104");

//2.获取与HBase的连接

Connection connection = ConnectionFactory.createConnection(configuration);

//3.获取DDL操作对象

Admin admin = connection.getAdmin();

//4.判断表是否存在操作

boolean exists = admin.tableExists(TableName.valueOf(tableName));

//5.关闭连接

admin.close();

connection.close();

//6.返回结果

return exists;

}

@Test

public
void isTableExist()
throws IOException {

boolean b = isTableExist("student");

System.out.println(b);

}

• 创建表

//创建表

public
static
void createTable(String tableName, String... cfs)
throws IOException {

//1.判断是否存在列族信息

if
(cfs.length <=
0)
{

System.out.println("请设置列族信息！");

return;

}

//2.判断表是否存在

if
(isTableExist(tableName))
{

System.out.println("需要创建的表已存在！");

return;

}

//3.创建配置信息并配置

Configuration configuration = HBaseConfiguration.create();

configuration.set("hbase.zookeeper.quorum",
"hadoop102,hadoop103,hadoop104");

//4.获取与HBase的连接

Connection connection = ConnectionFactory.createConnection(configuration);

//5.获取DDL操作对象

Admin admin = connection.getAdmin();

//6.创建表描述器构造器

TableDescriptorBuilder tableDescriptorBuilder = TableDescriptorBuilder.newBuilder(TableName.valueOf(tableName));

//7.循环添加列族信息

for
(String cf : cfs)
{

ColumnFamilyDescriptorBuilder columnFamilyDescriptorBuilder = ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes(cf));

tableDescriptorBuilder.setColumnFamily(columnFamilyDescriptorBuilder.build());

}

//8.执行创建表的操作

admin.createTable(tableDescriptorBuilder.build());

//9.关闭资源

admin.close();

connection.close();

}

@Test

public
void createTable()
throws IOException {

createTable("student1","info1",
"info2");

}

• 删除表

//删除表

public
static
void dropTable(String tableName)
throws IOException {

//1.判断表是否存在

if
(!isTableExist(tableName))
{

System.out.println("需要删除的表不存在！");

return;

}

//2.创建配置信息并配置

Configuration configuration = HBaseConfiguration.create();

configuration.set("hbase.zookeeper.quorum",
"hadoop102,hadoop103,hadoop104");

//3.获取与HBase的连接

Connection connection = ConnectionFactory.createConnection(configuration);

//4.获取DDL操作对象

Admin admin = connection.getAdmin();

//5.使表下线

TableName name = TableName.valueOf(tableName);

admin.disableTable(name);

//6.执行删除表操作

admin.deleteTable(name);

//7.关闭资源

admin.close();

connection.close();

}

@Test

public
void dropTable()
throws IOException {

dropTable("student1");

}

• 创建命名空间

//创建命名空间

public
static
void createNameSpace(String ns)
throws IOException {

//1.创建配置信息并配置

Configuration configuration = HBaseConfiguration.create();

configuration.set("hbase.zookeeper.quorum",
"hadoop102,hadoop103,hadoop104");

//2.获取与HBase的连接

Connection connection = ConnectionFactory.createConnection(configuration);

//3.获取DDL操作对象

Admin admin = connection.getAdmin();

//4.创建命名空间描述器

NamespaceDescriptor namespaceDescriptor = NamespaceDescriptor.create(ns).build();

//5.执行创建命名空间操作

try
{

admin.createNamespace(namespaceDescriptor);

}
catch
(NamespaceExistException e)
{

System.out.println("命名空间已存在！");

}
catch
(Exception e)
{

e.printStackTrace();

}

//6.关闭连接

admin.close();

connection.close();

}

@Test

public
void createNameSpace()
throws IOException {

createNameSpace("test1");

}

DML 增删改查

• 创建类HBase_DML
• 插入数据

//插入数据

//tableName 表名

//rowKey 主键

//cf 列族名

//字段名称

//需要添加到值

public
static
void putData(String tableName, String rowKey, String cf, String cn, String value)
throws IOException {

//1.获取配置信息并设置连接参数

Configuration configuration = HBaseConfiguration.create();

configuration.set("hbase.zookeeper.quorum",
"hadoop102,hadoop103,hadoop104");

//2.获取连接

Connection connection = ConnectionFactory.createConnection(configuration);

//3.获取表的连接

Table table = connection.getTable(TableName.valueOf(tableName));

//4.创建Put对象

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

//5.放入数据

put.addColumn(Bytes.toBytes(cf), Bytes.toBytes(cn), Bytes.toBytes(value));

//6.执行插入数据操作

table.put(put);

//7.关闭连接

table.close();

connection.close();

}

@Test

public
void putData()
throws IOException {

String tableName =
"student1";

String rowKey =
"001";

String cf =
"info1";

String cn =
"name";

String value =
"zhangshan";

putData(tableName, rowKey, cf, cn, value);

}

• 单条数据查询(GET)

//单条数据查询(GET)

public
static
void getDate(String tableName, String rowKey, String cf, String cn)
throws IOException {

//1.获取配置信息并设置连接参数

Configuration configuration = HBaseConfiguration.create();

configuration.set("hbase.zookeeper.quorum",
"hadoop102,hadoop103,hadoop104");

//2.获取连接

Connection connection = ConnectionFactory.createConnection(configuration);

//3.获取表的连接

Table table = connection.getTable(TableName.valueOf(tableName));

//4.创建Get对象

Get get =
new Get(Bytes.toBytes(rowKey));

// 指定列族查询

// get.addFamily(Bytes.toBytes(cf));

// 指定列族:列查询

// get.addColumn(Bytes.toBytes(cf), Bytes.toBytes(cn));

//5.查询数据

Result result = table.get(get);

//6.解析result

for
(Cell cell : result.rawCells())
{

System.out.println("ROW:"
+ Bytes.toString(CellUtil.cloneRow(cell))
+

" CF:"
+ Bytes.toString(CellUtil.cloneFamily(cell))
+

" CL:"
+ Bytes.toString(CellUtil.cloneQualifier(cell))
+

" VALUE:"
+ Bytes.toString(CellUtil.cloneValue(cell)));

}

//7.关闭连接

table.close();

connection.close();

}

@Test

public
void getDate()
throws IOException {

String tableName =
"student1";

String rowKey =
"001";

String cf =
"info1";

String cn =
"name";

getDate(tableName, rowKey, cf, cn);

}

• 扫描数据(Scan)

//扫描数据(Scan)

public
static
void scanTable(String tableName)
throws IOException {

//1.获取配置信息并设置连接参数

Configuration configuration = HBaseConfiguration.create();

configuration.set("hbase.zookeeper.quorum",
"hadoop102,hadoop103,hadoop104");

//2.获取连接

Connection connection = ConnectionFactory.createConnection(configuration);

//3.获取表的连接

Table table = connection.getTable(TableName.valueOf(tableName));

//4.创建Scan对象

Scan scan =
new Scan();

//5.扫描数据

ResultScanner results = table.getScanner(scan);

//6.解析results

for
(Result result : results)
{

for
(Cell cell : result.rawCells())
{

System.out.println(

Bytes.toString(CellUtil.cloneRow(cell))+":"+

Bytes.toString(CellUtil.cloneFamily(cell))+":"
+

Bytes.toString(CellUtil.cloneQualifier(cell))
+":"
+

Bytes.toString(CellUtil.cloneValue(cell))

);

}

}

//7.关闭资源

table.close();

connection.close();

}

@Test

public
void scanTable()
throws IOException {

scanTable("student1");

}

• 删除数据

//删除数据

public
static
void deletaData(String tableName, String rowKey, String cf, String cn)
throws IOException {

//1.获取配置信息并设置连接参数

Configuration configuration = HBaseConfiguration.create();

configuration.set("hbase.zookeeper.quorum",
"hadoop102,hadoop103,hadoop104");

//2.获取连接

Connection connection = ConnectionFactory.createConnection(configuration);

//3.获取表的连接

Table table = connection.getTable(TableName.valueOf(tableName));

//4.创建Delete对象

Delete delete =
new Delete(Bytes.toBytes(rowKey));

// 指定列族删除数据

// delete.addFamily(Bytes.toBytes(cf));

// 指定列族:列删除数据(所有版本)

// delete.addColumn(Bytes.toBytes(cf), Bytes.toBytes(cn));

// 指定列族:列删除数据(指定版本)

// delete.addColumns(Bytes.toBytes(cf), Bytes.toBytes(cn));

//5.执行删除数据操作

table.delete(delete);

//6.关闭资源

table.close();

connection.close();

}

@Test

public
void deletaData()
throws IOException {

String tableName =
"student1";

String rowKey =
"001";

String cf =
"info1";

String cn =
"name";

deletaData(tableName, rowKey, cf, cn);

}