这里演示在Windows上运行示例

配置Hosts

在Windows的Hosts文件夹中加入集群的所有节点

1.1.1.1 master
2.2.2.2 slave1

配置Hadoop

  1. 复制已在集群上安装的Hadoop文件到本地。文件比较多，可以压缩后复制

从master上复制

# 压缩文件夹
cd /opt/
zip -r hadoop.zip /hadoop
# 将/opt/hadoop.zip复制到本地

  1. 解压hadoop.zip到本地某目录，注意：目录中不能有空格

  2. 编辑hadoop\etc\hadoop\hadoop-env.cmd中的JAVA_HOME

:: 首先在cmd里找到JAVA_HOME
echo %JAVA_HOME%
:: => D:\Program_Files\Semeru\jdk-17.0.1.12-openj9\
:: 编辑hadoop-env.cmd中的JAVA_HOME
:: =>
JAVA_HOME=D:\Program_Files\Semeru\jdk-17.0.1.12-openj9\
  1. 配置HADOOP环境变量

在系统变量中加入

HADOOP_HOME=hadoop_path_here
HADOOP_USER_NAME=root

在path中加入

%HADOOP_HOME%\bin
%HADOOP_HOME%\sbin

  1. 将winutils复制进hadoop\bin中

  2. 测试hadoop version，正常则成功 hv

创建测试数据

在hbase shell中:

create 'scores','grade','course'
put 'scores','1001','grade:','1'  
put 'scores','1001','course:art','80'  
put 'scores','1001','course:math','89'  
put 'scores','1002','grade:','2'  
put 'scores','1002','course:art','87'  
put 'scores','1002','course:math','57'  
put 'scores','1003','course:math','90'
# 查看插入的数据
scan "scores"

创建工程

这里用到的IDE是eclipse

  1. 下载master上的hbase/lib
cd /opt/hbase
zip -r lib.zip lib/
# hdfs dfs -put lib.zip /

  1. 将lib文件夹放入工程目录，并选中lib下的和lib\client-facing-thirdparty的所有jar文件，右键->build path->add to path

  2. 创建包demo，创建类Main

package demo;

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 java.io.IOException;

public class Main {
	public static void main(String[] args) {
		System.setProperty("hadoop.home.dir", "D:\\Program_Files\\hadoop");
		Configuration connection= HBaseConfiguration.create();
		Admin admin;
		try {
			connection.addResource("hbase-site.xml");
			// 创建数据库链接
			Connection conn = ConnectionFactory.createConnection(connection);
			admin = conn.getAdmin();
			System.out.println("===开始连接到HBase上并显示所有表===");
			for (TableName tn : admin.listTableNames())
				System.out.println(tn);
			System.out.println("服务器测试成功!");
			Table tb = conn.getTable(TableName.valueOf("scores"));
			ResultScanner scanner=tb.getScanner(new Scan());//全表扫描
			for(Result row : scanner){
				for (Cell cell : row.listCells()) {
					System.out.println("Rowkey:" + Bytes.toString(row.getRow()) +
					" Familiy:"+ Bytes.toString(CellUtil.cloneFamily(cell)) +
					" Qualifier:"+ Bytes.toString(CellUtil.cloneQualifier(cell)) +
					" Value:"+ Bytes.toString(CellUtil.cloneValue(cell)));
				}
			}
			conn.close();// 关闭连接
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}
  1. 在工程根目录创建hbase-site.xml
<configuration>
 <property>
 <name>hbase.rootdir</name>
 <value>hdfs://master:9000/hbase</value>
 </property>
 <property>
 <name>hbase.cluster.distributed</name>
 <value>true</value>
 </property>
 <property>
 <name>hbase.master.port</name>
 <value>16000</value>
 </property>
 <property>
 <name>hbase.zookeeper.quorum</name>
 <value>master:2181,slave1:2181</value>
 </property>
 <property>
 <name>hbase.zookeeper.property.dataDir</name>
 <value>/opt/apache-zookeeper-3.8.0-bin/data</value>
 </property>
 <property>
 <name>hbase.unsafe.stream.capability.enforce</name>
 <value>false</value>
 </property>
</configuration>
  1. 在根目录创建log4j.properties，只展示error日志。可以改成info或者warn
log4j.rootLogger=error,console

log4j.appender.console=org.apache.log4j.ConsoleAppender
log4j.appender.console.layout=org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern=%d %p [%c] - %m%n
  1. 运行Main.java，如果能正常读出写入的数据即成功 main.java