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How can i downgrade the java version 11 to java 8. As i need jenkins, current jenkins versoin doesn't support java 11. I need to downgrade.

Rajesh Ganessan
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1 Answers1

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  1. You have to install the openjdk-8-jre:

     sudo apt-get install openjdk-8-jre

  2. Next switch to the jre-8 version:

     $ sudo update-alternatives --config java
 There are 2 choices for the alternative java (providing /usr/bin/java).

 Selection    Path                                            Priority   Status

 * 0            /usr/lib/jvm/java-9-openjdk-amd64/bin/java       1500      auto mode
   1            /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java   1500      manual mode
   2            /usr/lib/jvm/java-9-openjdk-amd64/bin/java       1500      manual mode

  3. Add JAVA_HOME variable:

     export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64

  4. check java version:

     $ java -version
 openjdk version "1.8.0_151"
 OpenJDK Runtime Environment (build 1.8.0_151-8u151-b12-0ubuntu0.17.10.2-b12)
 OpenJDK 64-Bit Server VM (build 25.151-b12, mixed mode)

Same procedure for Oracle java.

Widuranga Dilruksha
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Maythux
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  • What is `update-alternatives`? I get `sudo: update-alternatives: command not found` when I try to run it. I don't have apt installed. Is it part of that? – Mike S. Oct 03 '19 at 18:33
  • When I try `sudo apt-get install openjdk-8-jre` I get this error: `Errors were encountered while processing: oracle-java11-installer-local. E: Sub-process /usr/bin/dpkg returned an error code (1).`How to remove oracle-java11-installer-local. – Kousalya Devi Jun 01 '20 at 03:11
  • What about uninstalling the unused jdk 11? – Anton Duzenko Mar 13 '23 at 12:13