uBuntu (22.04.2) install jdk1.8 manual

1. Download the jdk installation package of the corresponding system from the Oracle official website:

Java Downloads | Oraclehttps://www.oracle.com/java/technologies/downloads/#java17

        Select the corresponding .gz package to download

 2. Unzip and put it in the specified directory (take jre-8u361-linux-x64.tar.gz as an example)

　　1.) Create a directory:

sudo mkdir /usr/local/software/java

        2.) Move the jdk file downloaded in the /usr/local/software/java directory to the /usr/local/software/java directory:

sudo mv /usr/local/software/java/jre-8u361-linux-x64.tar.gz   /usr/local/software/java

       3.) Unzip the installation package to the current directory:

 sudo tar -zxvf jre-8u361-linux-x64.tar.gz -C /usr/local/software/java

3. Modify environment variables:　　

        Enter the command to open the configuration file:

sudo vim ~/.bashrc

        As shown in the figure, switch to the end of the text content and enter the following content:

#set oracle jdk environment
export JAVA_HOME=/usr/local/software/java/jre1.8.0_361  ## 这里要注意目录要换成自己解压的jdk 目录
export JRE_HOME=${JAVA_HOME}/jre
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib
export PATH=${JAVA_HOME}/bin:$PATH

 

：wq   

        Save and exit.

4. Test whether the installation is successful:

        Enter at the terminal command line:

 java -version

        The version number shown below indicates that the installation was successful: