配置hadoop-1.2.1出現localhost: Error: JAVA_HOME is not set.

配置hadoop-1.2.1出現localhost: Error: JAVA_HOME is not set.

具體爲：

hadoop@dy-virtual-machine:~/hadoop-1.2.1$ start-all.sh
starting namenode, logging to /home/hadoop/hadoop-1.2.1/libexec/../logs/hadoop-hadoop-namenode-dy-virtual-machine.out
localhost: starting datanode, logging to /home/hadoop/hadoop-1.2.1/libexec/../logs/hadoop-hadoop-datanode-dy-virtual-machine.out
localhost: Error: JAVA_HOME is not set.
localhost: starting secondarynamenode, logging to /home/hadoop/hadoop-1.2.1/libexec/../logs/hadoop-hadoop-secondarynamenode-dy-virtual-machine.out
localhost: Error: JAVA_HOME is not set.
starting jobtracker, logging to /home/hadoop/hadoop-1.2.1/libexec/../logs/hadoop-hadoop-jobtracker-dy-virtual-machine.out
localhost: starting tasktracker, logging to /home/hadoop/hadoop-1.2.1/libexec/../logs/hadoop-hadoop-tasktracker-dy-virtual-machine.out
localhost: Error: JAVA_HOME is not set.

 

解決方法:

在/hadoop-1.2.1/conf/文件夾裏有個hadoop-env.sh的文件，它的做用是配置與hadoop運行環境相關的變量

找到：

# The java implementation to use. Required.
# export JAVA_HOME=/usr/lib/jvm/java-6-sun

將#號去掉，變爲：

改爲你本機的jdk路徑，執行完退出

 ：wq

 

若你不清楚本身的jdk路徑，你能夠先執行 echo $JAVA_HOME   進行查看