Java SE JDK 12 and its installation in Linux Mint?

Question

linux

Hello everyone, I have a question about installing Java SE JDK 12 for programming on Linux Mint. Before that, in Windows, I simply downloaded packages, set variables, and everything compiled and ran in cmd without problems.
1) First of all, I downloaded SE 12 from offsite

https://www.oracle.com/technetwork/java/javase/dow...

2) Then I installed it using sudo dpkg -i java.deb
3) When I call the information in the console, I get something like this

sudo java -version     
openjdk version "10.0.2" 2018-07-17
OpenJDK Runtime Environment (build 10.0.2+13-Ubuntu-1ubuntu0.18.04.4)
OpenJDK 64-Bit Server VM (build 10.0.2+13-Ubuntu-1ubuntu0.18.04.4, mixed mode)

Why am I getting a completely different version, I have jdk12? If I delete it, the system unambiguously hints that irreversible things will happen next:

sudo apt remove openjdk-11-jre openjdk-11-jre-headless
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
ibm-java80-jre libreoffice-avmedia-backend -gstreamer libreoffice-base
libreoffice-base-core libreoffice-base-drivers libreoffice-calc
libreoffice-common libreoffice-core libreoffice-draw libreoffice-gnome
libreoffice-gtk3 libreoffice-impress libreoffice-java-common
libreoffice-math libreoffice-ogltrans libreoffice-pdfimport
libreoffice-sdbc-hsqldb libreoffice-style-galaxy libreoffice-style-tango libreoffice
-writer python3-uno
ibm-java80-plugin libreoffice-report-builder unixodbc libjtds-java
libreoffice-mysql-connector | libmyodbc | libmysql-java
libreoffice-sdbc-postgresql | odbc-postgresql | libpg-java libsqliteodbc
| tdsodbc | mdbtools libreoffice-sdbc-firebird ocl-icd-libopencl1
libreoffice-evolution libreofficekit-data tango-icon-theme
fonts-crosextra-caladea fonts-crosextra-carlito
Recommended packages:
gstreamer1.0-gtk3
The following packages will be REMOVED:
default-jre default-jre-headless openjdk-11-jre openjdk-11-jre-headless
The following NEW packages will be installed:
ibm-java80-jre
The following packages will be upgraded:
libreoffice-avmedia-backend-gstreamer libreoffice-base libreoffice-base-core
libreoffice-base-drivers libreoffice-calc libreoffice-common
libreoffice-core libreoffice-draw libreoffice-gnome libreoffice-gtk3
libreoffice-impress libreoffice-java-common libreoffice-math
libreoffice -ogltrans libreoffice-pdfimport libreoffice-sdbc-hsqldb
libreoffice-style-galaxy libreoffice-style-tango libreoffice-writer
python3-uno
20 upgraded, 1 newly installed, 4 to remove and 451 not upgraded.
Need to get 194 MB of archives.
After this operation, 13.5 MB of additional disk space will be used.
Do you want to continue? [Y/n] n
Abort.

How can I replace these openjdk and openjre with freshly downloaded 12 versions?
How to set environment variables to refer to correct javac and java?

Answer 1

Where did you see irreversible things? Something will be deleted and something will be updated, that's it, no more terrible changes. Do it first sudo apt update && sudo apt dist-upgradeand then delete, the message will become a little less scary

Answer 2

sudo update-alternatives --list java
it will show you what is already there and you will see openjdk 11
(mint is debian based) there

Usage: update-alternatives [<option> ...] <command>

Commands:
  --install <link> <name> <path> <priority>
    [--slave <link> <name> <path>] ...
                           add a group of alternatives to the system.

<link> is the symlink pointing to /etc/alternatives/<name>.
  (e.g. /usr/bin/pager)
<name> is the master name for this link group.
  (e.g. pager)
<path> is the location of one of the alternative target files.
  (e.g. /usr/bin/less)
<priority> is an integer; options with higher numbers have higher priority in
  automatic mode.

that is, you need a type
- your path will be different - I took a 16-bit cat from one of my test virtual machines. use for testing