hadoop 启动 JAVA_HOME is not set and could not be found

[root@mysqlmaster hadoop-2.7.2]# sbin/start-dfs.sh
16/07/01 18:38:03 DEBUG util.Shell: setsid exited with exit code 0
16/07/01 18:38:03 DEBUG lib.MutableMetricsFactory: field org.apache.hadoop.metrics2.lib.MutableRate org.apache.hadoop.security.UserGroupInformation$UgiMetrics.loginSuccess with annotation @org.apache.hadoop.metrics2.annotation.Metric(valueName=Time, about=, value=[Rate of successful kerberos logins and latency (milliseconds)], always=false, type=DEFAULT, sampleName=Ops)
16/07/01 18:38:03 DEBUG lib.MutableMetricsFactory: field org.apache.hadoop.metrics2.lib.MutableRate org.apache.hadoop.security.UserGroupInformation$UgiMetrics.loginFailure with annotation @org.apache.hadoop.metrics2.annotation.Metric(valueName=Time, about=, value=[Rate of failed kerberos logins and latency (milliseconds)], always=false, type=DEFAULT, sampleName=Ops)
16/07/01 18:38:03 DEBUG lib.MutableMetricsFactory: field org.apache.hadoop.metrics2.lib.MutableRate org.apache.hadoop.security.UserGroupInformation$UgiMetrics.getGroups with annotation @org.apache.hadoop.metrics2.annotation.Metric(valueName=Time, about=, value=[GetGroups], always=false, type=DEFAULT, sampleName=Ops)
16/07/01 18:38:03 DEBUG impl.MetricsSystemImpl: UgiMetrics, User and group related metrics
16/07/01 18:38:04 DEBUG security.Groups:  Creating new Groups object
16/07/01 18:38:04 DEBUG util.NativeCodeLoader: Trying to load the custom-built native-hadoop library...
16/07/01 18:38:04 DEBUG util.NativeCodeLoader: Loaded the native-hadoop library
16/07/01 18:38:04 DEBUG security.JniBasedUnixGroupsMapping: Using JniBasedUnixGroupsMapping for Group resolution
16/07/01 18:38:04 DEBUG security.JniBasedUnixGroupsMappingWithFallback: Group mapping impl=org.apache.hadoop.security.JniBasedUnixGroupsMapping
16/07/01 18:38:04 DEBUG security.Groups: Group mapping impl=org.apache.hadoop.security.JniBasedUnixGroupsMappingWithFallback; cacheTimeout=300000; warningDeltaMs=5000
16/07/01 18:38:04 DEBUG security.UserGroupInformation: hadoop login
16/07/01 18:38:04 DEBUG security.UserGroupInformation: hadoop login commit
16/07/01 18:38:04 DEBUG security.UserGroupInformation: using local user:UnixPrincipal: root
16/07/01 18:38:04 DEBUG security.UserGroupInformation: Using user: "UnixPrincipal: root" with name root
16/07/01 18:38:04 DEBUG security.UserGroupInformation: User entry: "root"
16/07/01 18:38:04 DEBUG security.UserGroupInformation: UGI loginUser:root (auth:SIMPLE)
16/07/01 18:38:04 DEBUG security.UserGroupInformation: PrivilegedAction as:root (auth:SIMPLE) from:org.apache.hadoop.hdfs.tools.GetConf.run(GetConf.java:315)
Starting namenodes on [localhost]
root@localhost's password:
localhost: Error: JAVA_HOME is not set and could not be found.
root@localhost's password:

[1]+ Stopped sbin/start-dfs.sh

Solution:

Solution:
# vim /home/hadoop/.bashrc Add the following content

export JAVA_HOME=/usr/local/jdk1.7.0_65
export PATH=$PATH :$JAVA_HOME/bin
export HADOOP_PREFIX=/home/hadoop/hadoop-2.7.1