Installing the Java Environment

Procedure

1. Obtain the Java package jdk-8u152-linux-arm64-vfp-hflt.tar.gz. For details, see the software requirements.
2. Use PuTTY to log in to the server as the root user.
3. Run the following commands to install the Java environment:

   mkdir /path/to/HADOOP
   cd path/to/HADOOP
   tar -zxvf jdk-8u152-linux-arm64-vfp-hflt.tar.gz

   

   Differences between JRE and JDK:

   • The Java Runtime Environment (JRE) is the environment required for Java running.
   • The Java Development Kit (JDK) includes the JRE and the tools and class libraries required for Java development.
4. Configure environment variables and modify the /root/.bashrc file.
   1. Open the file.

      vi /root/.bashrc

   2. Press i to enter the insert mode and add the following path to the end of the /root/.bashrc file:

      export JAVA_HOME=path/to/HADOOP/jdk1.8.0_171
      export JRE_HOME=$JAVA_HOME/jre
      export PATH=:$JAVA_HOME/bin:$PATH
      export CLASSPATH=.:$CLASSPATH:$JAVA_HOME/lib:$JRE_HOME/lib

   3. Press Esc, type :wq!, and press Enter to save the file and exit.