Question

我正在尝试在hadoop服务器上运行以下java代码。

javac -classpath ${HADOOP_HOME}/hadoop-${HADOOP_VERSION}-core.jar -d wordcount_classes WordCount.java

但我无法找到{HADOOP_HOME}。我尝试使用hadoop -classpath，但它输出如下：

/etc/hadoop/conf:/usr/lib/hadoop/lib/*:/usr/lib/hadoop/.//*:/usr/lib/hadoop-hdfs/./:/usr/lib/hadoop-hdfs/lib/*:/usr/lib/hadoop-hdfs/.//*:/usr/lib/hadoop-yarn/.//*:/usr/lib/hadoop-0.20-mapreduce/./:/usr/lib/hadoop-0.20-mapreduce/lib/*:/usr/lib/hadoop-0.20-mapreduce/.//*

有人对此有任何想法吗？

Answer 1

hadoop-core jar文件位于$ {HADOOP_HOME} / share / hadoop / common目录中，而不在$ {HADOOP_HOME}目录中。

您可以在.bashrc文件中设置环境变量。

vim ~/.bashrc

然后将以下行添加到.bashrc文件的末尾。

export HADOOP_HOME=/your/hadoop/installation/directory

只需用hadoop安装路径替换路径。

Answer 2

导航到安装hadoop的路径并更改目录，如下所示

/usr/lib/hadoop-2.2.0/etc/hadoop

当您输入ls命令时，您应该看到所有这些文件。

capacity-scheduler.xml      httpfs-site.xml
configuration.xsl           log4j.properties
container-executor.cfg      mapred-env.cmd
core-site.xml               mapred-env.sh
core-site.xml~              mapred-queues.xml.template
hadoop-env.cmd              mapred-site.xml
hadoop-env.sh               mapred-site.xml~
hadoop-env.sh~              mapred-site.xml.template
hadoop-metrics2.properties  slaves
hadoop-metrics.properties   ssl-client.xml.example
hadoop-policy.xml           ssl-server.xml.example
hdfs-site.xml               yarn-env.cmd
hdfs-site.xml~              yarn-env.sh
httpfs-env.sh               yarn-site.xml
httpfs-log4j.properties     yarn-site.xml~
httpfs-signature.secret

核心配置设置在hadoop-env.sh中可用。

您可以在此文件中看到类路径设置，我在此处复制了一些示例供您参考。

# The java implementation to use.
export JAVA_HOME=/usr/lib/jvm/jdk1.7.0_67

# The jsvc implementation to use. Jsvc is required to run secure datanodes.
#export JSVC_HOME=${JSVC_HOME}

export HADOOP_CONF_DIR=${HADOOP_CONF_DIR}

# Extra Java CLASSPATH elements.  Automatically insert capacity-scheduler.
for f in $HADOOP_HOME/contrib/capacity-scheduler/*.jar; do
  if [ "$HADOOP_CLASSPATH" ]; then
    export HADOOP_CLASSPATH=$HADOOP_CLASSPATH:$f
  else
    export HADOOP_CLASSPATH=$f
  fi
done

希望这有帮助！

如何在Linux上找到HADOOP_HOME路径？

2 个答案: