无法在ubuntu上安装java9

Question

I already have java8 working but when I try to install java9 this is what happens everytime:

sudo apt-get install oracle-java9-installer

Reading package lists... Done Building dependency tree Reading state information... Done Package oracle-java9-installer is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source

E: Package 'oracle-java9-installer' has no installation candidate

Answer 1

It seems Oracle stopped supporting Java 9 so the PPA does not contain Java9 installer anymore. There is nothing wrong on your end, with your machine.

It looks like Java9 is a short-term support version, and so will java 10 be too. Java 11 will be a LTS support. For more details on the new Java release approach see this answer .

Because this, you can't install Java9 using the ppm anymore, you have to do it manually. You will have to go to the java 9 archive downloads , log in with an Oracle account, download the .tar.gz, extract the .tar.gz and copy it to the install location.

Answer 2

做

sudo apt install default-jre default-jdk

Answer 3

This likely happened because the "prerequisites" were not set.

Try using:

sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java9-installer

Once this is done, edit the system environment variables:

sudo nano /etc/environment

Then add this to the file:

JAVA_HOME="/usr/lib/jvm/java-9-oracle"

I believe this will only work on Ubuntu 16.04.

Source: https://askubuntu.com/questions/961300/how-can-i-install-the-latest-jdk-9-using-terminal-command-on-ubuntu-16-04-lts