[start-dfs.sh] Hadoop 配置最后出现JAVA_HOME没有被设置和找到的错误

说明：本地机器1台，配置为master，本地机器虚拟1个slave，然后远程端机器1台slave。参照一些配置顺序的教程后，出现上述问题。因为是新手，想请教下问题在哪，或者能否有成功的朋友，给个可以实现的教程，我学习下，谢谢各位。

这个最后出现JAVA_HOME 没有设置和找到，但是我检查了，这个应该是配置好了的。请问是怎么回事呢？

[root@master sbin]# ./start-dfs.sh

15/11/06 09:20:00 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable

Starting namenodes on [master]

The authenticity of host 'master (10.211.40.7)' can't be established.

RSA key fingerprint is9a:23:5b:f1:da:d9:6a:c0:7d:0e:d7:a6:c3:46:d8:0a.

Are you sure you want to continue connecting (yes/no)? yes

master: Warning: Permanently added 'master' (RSA) to the list of known hosts.

master: Error: JAVA_HOME is not set and could not be found.

slave2: Error: JAVA_HOME is not set and could not be found.

slave1: Error: JAVA_HOME is not set and could not be found.

Starting secondary namenodes [master]

master: Error: JAVA_HOME is not set and could not be found.

15/11/06 09:20:12 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable

[root@master sbin]# ./start-dfs.sh 15/11/06 09:33:08 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable Starting namenodes on [master] master: Error: JAVA_HOME is not set and could not be found. slave2: Error: JAVA_HOME is not set and could not be found. slave1: Error: JAVA_HOME is not set and could not be found. Starting secondary namenodes [master] master: Error: JAVA_HOME is not set and could not be found. 15/11/06 09:33:12 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable [root@master sbin]# echo $JAVA_HOME /usr/program/jdk8
这是后面一次的错误信息