Hadoop 获取Active Namenode的IP地址

       由于工作需要，需要拿到当前集群的Active Namenode的Ip地址，所以写以下小代码，防止忘记，记录一下：

import java.io.IOException;
import java.net.InetSocketAddress;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.hdfs.HAUtil;

public class ActiveNNAdd {

public void getNameNodeAdress() throws Exception {
Configuration conf = new Configuration();

FileSystem system = null;
try {
system = FileSystem.get(conf);
InetSocketAddress active = HAUtil.getAddressOfActive(system);
System.out.println(active.getHostString()); 
// System.out.println("hdfs port:" + active.getPort());
// InetAddress address = active.getAddress();
// System.out.println("hdfs://" + address.getHostAddress() + ":"+ active.getPort()); 
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (system != null) {
system.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}


public static void main(String[] args) {


ActiveNNAdd nn = new ActiveNNAdd() ;

try {
nn.getNameNodeAdress();
} catch (Exception e) {
e.printStackTrace();
}


}


}

  以上代码是使用Hadoop源码提供的HAUtil工具类来做的，有兴趣的小伙伴还可以尝试连接Zookeeper获取！