创建maven项目
pom.xml文件内容: 3个依赖包 hbase-client hadoop-hdfs jdk.tools
连接hbase的两种方法:
配置法(不一定要按图配置,程序会默认去读classpath下的配置文件,可以通过System.out.println(ClassLoader.getSystemResource("").toString());获取)
1 在main文件夹下,建立resources文件夹,在resources文件夹下建立hbase文件,hbase文件夹下放hbase-site.xml配置文件(主要用到里面的zookeeper配置信息)
配置文件主要内容如下:
hbase-site.xml
代码:
package myHbase;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.Cell.Type;
import org.apache.hadoop.hbase.CellBuilder;
import org.apache.hadoop.hbase.CellBuilderFactory;
import org.apache.hadoop.hbase.CellBuilderType;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.HBaseAdmin;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.util.Bytes;
public class SimpleTest {
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
Configuration hBaseConfig = HBaseConfiguration.create();
HBaseAdmin.available(hBaseConfig);
Connection connection = ConnectionFactory.createConnection(hBaseConfig);
TableName table1 = TableName.valueOf("test");
Table table = connection.getTable(table1);
CellBuilder cb = CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY);
cb.setRow(Bytes.toBytes("row3"));
cb.setFamily(Bytes.toBytes("cf"));
cb.setQualifier("qualifier1".getBytes());
cb.setValue(Bytes.toBytes("mjj2"));
cb.setType(Type.Put);
Cell cell = cb.build();
Put p = new Put(Bytes.toBytes("row3"));
p.add(cell);
table.put(p);
connection.close();
}
}
配置不正确报错(zookeeper的连接丢失):
Exception in thread "main" org.apache.hadoop.hbase.MasterNotRunningException: org.apache.hadoop.hbase.MasterNotRunningException: java.io.IOException: org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode = ConnectionLoss for /hbase/master
代码里设定zookeeper:
package myHbase;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.Cell.Type;
import org.apache.hadoop.hbase.CellBuilder;
import org.apache.hadoop.hbase.CellBuilderFactory;
import org.apache.hadoop.hbase.CellBuilderType;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.HBaseAdmin;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.util.Bytes;
public class SimpleTest {
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
Configuration hBaseConfig = HBaseConfiguration.create();
hBaseConfig.set("hbase.zookeeper.quorum", "192.168.50.107");
hBaseConfig.set("hbase.zookeeper.property.clientPort", "2181");
HBaseAdmin.available(hBaseConfig);
Connection connection = ConnectionFactory.createConnection(hBaseConfig);
TableName table1 = TableName.valueOf("test");
Table table = connection.getTable(table1);
CellBuilder cb = CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY);
cb.setRow(Bytes.toBytes("row3"));
cb.setFamily(Bytes.toBytes("cf"));
cb.setQualifier("qualifier1".getBytes());
cb.setValue(Bytes.toBytes("mjj2"));
cb.setType(Type.Put);
Cell cell = cb.build();
Put p = new Put(Bytes.toBytes("row3"));
p.add(cell);
table.put(p);
connection.close();
}
}
重要: windows上一定要配置/etc/hosts. 添加一条 192.168.50.107 rhel -------其中rhel 为 hbase机子的主机名。原因未知。
否则报错:
Exception in thread "main" org.apache.hadoop.hbase.MasterNotRunningException: org.apache.hadoop.hbase.MasterNotRunningException: java.net.UnknownHostException: can not resolve rhel,16000,1530027948780