遇到这个其实不难解决！
解决办法1：
[[email protected] hadoop]# vi /etc/selinux/config改为：
SELINUX=disabled解决办法2：
查看你的$HADOOP_HOME/etc/hadoop下的core-site.xml和hdfs-site.xml是否配置好
解决办法3：
必须在hadoop-env.sh文件中设置Java的绝对路径
解决办法4：
是否关闭linux系统的防火墙
centos6:
[[email protected] ~]# service iptables status
[[email protected]t002 ~]# chkconfig iptables off
//永久关闭防火墙
[[email protected] ~]# service iptables stop //临时关闭防火墙
[[email protected] ~]# service iptables status
iptables: Firewall is not running.ccentos7:
[[email protected] ~]# systemctl status firewalld //查看状态
[[email protected] ~]# systemctl stop firewalld //关闭防火墙
[[email protected] ~]# systemctl start firewalld //启动防火墙
[[email protected] ~]# systemctl disable firewalld //开机禁用防火墙
[[email protected] ~]# systemctl enable firewalld //开机启动防火墙