This article will show you how to upgrade Java 8 to Java 11 on Ubuntu 20.04. Java is one of the most popular programming languages in the world, used for building a wide range of applications from desktops to mobile and web applications. Java 11, also known as Java SE 11, is a long-term support (LTS) version of the Java programming language, and it provides several new features and enhancements over its predecessor, Java 8. This blog will discuss how to upgrade Java 8 to Java 11 on Ubuntu 20.
Java 11, also known as Java SE 11, was released on September 25, 2018, and is a long-term support (LTS) version of the Java programming language. Some of the key features of Java 11 include:
- The local variable syntax for lambda parameters: This feature allows you to use the “var” keyword to declare the type of a lambda parameter, making code more concise and readable.
- Flight Recorder: This feature allows you to record and analyze events and performance data in real-time or after the fact, making diagnosing and fixing problems in your application easier.
- Epsilon GC: This is a new garbage collector that is designed for use cases where very short pauses are acceptable, but low memory footprints and high throughput are required.
- HTTP Client: This is a new standardized HTTP client API that supports HTTP/1.1 and HTTP/2, and provides support for WebSocket and HTTP/2 server push.
- Unicode 10: Java 11 supports Unicode 10.0.0, which adds over 8,000 characters, including new emoji characters.
- Improved Docker support: Java 11 includes enhancements to better support running Java applications in Docker containers, including better memory handling and process identification.
- Nest-based access control: This feature allows classes to be nested inside other classes, and provides improved access control for nested classes.
- TLS 1.3 support: Java 11 includes support for TLS 1.3, which provides improved security and performance over previous versions of TLS.
- JEP 321: HTTP Client (Standard): This feature provides a new standard HTTP client API in the java.net.http package.
- JEP 330: Launch Single-File Source-Code Programs: This feature allows you to run a Java source file as a standalone program without compiling it first.
Overall, Java 11 includes many new features and improvements that make it easier to develop and deploy Java applications.
Java 8 to Java 11 Upgrade: Dos, Don’ts, and Common Mistakes on Ubuntu 20
| Dos | Don’ts | Common Mistakes |
|---|---|---|
| Do take a backup of your codebase and critical data before upgrading. | Don’t directly upgrade from Java 8 to Java 11 without testing. | Failing to back up important files before upgrading, leading to data loss. |
| Do update your build tools (e.g., Maven, Gradle) to their latest versions. | Don’t forget to update third-party libraries and dependencies. | Using outdated build tools, causing compatibility issues. |
| Do thoroughly test your application with Java 11 on a staging environment. | Don’t assume everything will work the same as with Java 8. | Skipping testing and encountering runtime errors in production. |
| Do check for Java 11 compatibility in all your dependencies and frameworks. | Don’t ignore deprecated APIs in Java 8 that are removed in Java 11. | Relying on deprecated APIs, leading to runtime issues in Java 11. |
| Do read the release notes and migration guides for Java 11. | Don’t forget to update environment variables like JAVA_HOME. | Setting incorrect environment variables, causing version confusion. |
| Do ensure your hardware and system requirements meet Java 11 specifications. | Don’t disable or ignore warnings during the compilation process. | Suppressing warnings can hide potential issues in your code. |
| Do use the latest stable version of OpenJDK 11 for better performance and security. | Don’t mix Java 8 and Java 11 code in the same project without proper segregation. | Combining different Java versions may lead to unexpected behavior. |
| Do update any custom scripts or tools that rely on Java 8 functionalities. | Don’t overlook the impact of Java 11’s new licensing model (Oracle JDK vs. OpenJDK). | Using Oracle JDK without a proper license may lead to legal issues. |
| Do monitor your application’s performance after the upgrade. | Don’t assume your code is optimized for Java 11; consider performance tuning. | Neglecting performance tuning may result in suboptimal performance. |
| Do keep your development team informed and trained on Java 11 features. | Don’t rush the migration process; allocate enough time for thorough testing. | Hasty migration can lead to overlooked issues and delays. |
Steps to Upgrade Java 8 to Java 11 on Ubuntu 20.04
Note: Always ensure that your applications are compatible with the new Java version before making the switch in a production environment.
Step 1: Check the current installed Java version
$ java -version
Sample output:
sysadminxpert@Ubuntu:~$ java -version openjdk version "1.8.0_312" OpenJDK Runtime Environment (build 1.8.0_312-8u312-b07-0ubuntu1~20.04-b07) OpenJDK 64-Bit Server VM (build 25.312-b07, mixed mode)
Step 2: Install Java 11 on Ubuntu
$ sudo apt install openjdk-11-jdk
Sample output:
sysadminxpert@Ubuntu:~$ sudo apt install openjdk-11-jdk Reading package lists... Done Building dependency tree Reading state information... Done The following additional packages will be installed: openjdk-11-jdk-headless openjdk-11-jre openjdk-11-jre-headless Suggested packages: openjdk-11-demo openjdk-11-source visualvm fonts-ipafont-gothic fonts-ipafont-mincho fonts-wqy-microhei | fonts-wqy-zenhei The following NEW packages will be installed: openjdk-11-jdk openjdk-11-jdk-headless openjdk-11-jre openjdk-11-jre-headless 0 upgraded, 4 newly installed, 0 to remove and 613 not upgraded. Need to get 263 MB of archives. After this operation, 408 MB of additional disk space will be used. Do you want to continue? [Y/n] Y Get:1 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jre-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [37.3 MB] Get:1 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jre-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [37.3 MB] Get:1 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jre-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [37.3 MB] Get:1 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jre-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [37.3 MB] Get:1 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jre-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [37.3 MB] Get:1 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jre-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [37.3 MB] Get:1 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jre-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [37.3 MB] Get:2 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jre amd64 11.0.15+10-0ubuntu0.20.04.1 [175 kB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.15+10-0ubuntu0.20.04.1 [223 MB] Get:4 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk amd64 11.0.15+10-0ubuntu0.20.04.1 [2,573 kB] Fetched 22.5 MB in 29min 54s (12.5 kB/s) Selecting previously unselected package openjdk-11-jre-headless:amd64. (Reading database ... 146978 files and directories currently installed.) Preparing to unpack .../openjdk-11-jre-headless_11.0.15+10-0ubuntu0.20.04.1_amd64.deb ... Unpacking openjdk-11-jre-headless:amd64 (11.0.15+10-0ubuntu0.20.04.1) ... Selecting previously unselected package openjdk-11-jre:amd64. Preparing to unpack .../openjdk-11-jre_11.0.15+10-0ubuntu0.20.04.1_amd64.deb ... Unpacking openjdk-11-jre:amd64 (11.0.15+10-0ubuntu0.20.04.1) ... Selecting previously unselected package openjdk-11-jdk-headless:amd64. Preparing to unpack .../openjdk-11-jdk-headless_11.0.15+10-0ubuntu0.20.04.1_amd64.deb ... Unpacking openjdk-11-jdk-headless:amd64 (11.0.15+10-0ubuntu0.20.04.1) ... Selecting previously unselected package openjdk-11-jdk:amd64. Preparing to unpack .../openjdk-11-jdk_11.0.15+10-0ubuntu0.20.04.1_amd64.deb ... Unpacking openjdk-11-jdk:amd64 (11.0.15+10-0ubuntu0.20.04.1) ... Setting up openjdk-11-jre-headless:amd64 (11.0.15+10-0ubuntu0.20.04.1) ... update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/java to provide /usr/bin/java (java) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jjs to provide /usr/bin/jjs (jjs) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/keytool to provide /usr/bin/keytool (keytool) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/rmid to provide /usr/bin/rmid (rmid) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/rmiregistry to provide /usr/bin/rmiregistry (rmiregistry) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/pack200 to provide /usr/bin/pack200 (pack200) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/unpack200 to provide /usr/bin/unpack200 (unpack200) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/lib/jexec to provide /usr/bin/jexec (jexec) in auto mode Setting up openjdk-11-jre:amd64 (11.0.15+10-0ubuntu0.20.04.1) ... Setting up openjdk-11-jdk-headless:amd64 (11.0.15+10-0ubuntu0.20.04.1) ... update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jar to provide /usr/bin/jar (jar) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jarsigner to provide /usr/bin/jarsigner (jarsigner) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/javac to provide /usr/bin/javac (javac) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/javadoc to provide /usr/bin/javadoc (javadoc) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/javap to provide /usr/bin/javap (javap) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jcmd to provide /usr/bin/jcmd (jcmd) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jdb to provide /usr/bin/jdb (jdb) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jdeprscan to provide /usr/bin/jdeprscan (jdeprscan) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jdeps to provide /usr/bin/jdeps (jdeps) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jfr to provide /usr/bin/jfr (jfr) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jimage to provide /usr/bin/jimage (jimage) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jinfo to provide /usr/bin/jinfo (jinfo) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jlink to provide /usr/bin/jlink (jlink) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jmap to provide /usr/bin/jmap (jmap) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jmod to provide /usr/bin/jmod (jmod) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jps to provide /usr/bin/jps (jps) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jrunscript to provide /usr/bin/jrunscript (jrunscript) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jshell to provide /usr/bin/jshell (jshell) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jstack to provide /usr/bin/jstack (jstack) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jstat to provide /usr/bin/jstat (jstat) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jstatd to provide /usr/bin/jstatd (jstatd) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/rmic to provide /usr/bin/rmic (rmic) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/serialver to provide /usr/bin/serialver (serialver) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jaotc to provide /usr/bin/jaotc (jaotc) in auto mode update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jhsdb to provide /usr/bin/jhsdb (jhsdb) in auto mode Setting up openjdk-11-jdk:amd64 (11.0.15+10-0ubuntu0.20.04.1) ... update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/jconsole to provide /usr/bin/jconsole (jconsole) in auto mode Processing triggers for mime-support (3.64ubuntu1) ... Processing triggers for hicolor-icon-theme (0.17-2) ... Processing triggers for gnome-menus (3.36.0-1ubuntu1) ... Processing triggers for desktop-file-utils (0.24-1ubuntu2) ... sysadminxpert@Ubuntu:~$
Step 3: Set the default Java version on Ubuntu
If multiple Java versions are installed on your system, then you need to follow the steps below to set a default Java version.
Using the update-alternatives command to change the default Java version
$ sudo update-alternatives --config java
Sample output:
sysadminxpert@Ubuntu:~$ 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-11-openjdk-amd64/bin/java 1111 auto mode 1 /usr/lib/jvm/java-11-openjdk-amd64/bin/java 1111 manual mode * 2 /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java 1081 manual mode Press <enter> to keep the current choice[*], or type selection number: 0 update-alternatives: using /usr/lib/jvm/java-11-openjdk-amd64/bin/java to provide /usr/bin/java (java) in auto mode sysadminxpert@Ubuntu:~$
Also also update alternatives for Javac:
sudo update-alternatives --config javac
Verify java version
$ java -version
Sample output:
sysadminxpert@Ubuntu:~$ java -version openjdk version "11.0.15" 2022-04-19 OpenJDK Runtime Environment (build 11.0.15+10-Ubuntu-0ubuntu0.20.04.1) OpenJDK 64-Bit Server VM (build 11.0.15+10-Ubuntu-0ubuntu0.20.04.1, mixed mode, sharing) sysadminxpert@Ubuntu:~$
Step 4: Configure JAVA_HOME in Ubuntu (Environment Variables)
Add the below line in ~/.bashrc
export JAVA_HOME=$(readlink -f /usr/bin/java | sed "s:/bin/java::")
Step 5: Verify JAVA_HOME path in Ubuntu
source ~/.bashrc echo $JAVA_HOME
Sample Output:
sysadminxpert@Ubuntu:~$ echo $JAVA_HOME /usr/lib/jvm/java-11-openjdk-amd64
End of article. We have shown you how to upgrade Java 8 to Java 11 on Ubuntu 20.04
Step 6: Remove Java 8 (Optional)
If you no longer need Java 8, you can remove it:
sudo apt remove openjdk-8-jdk
Step 7: Update Java Applications
If you have Java applications, update their configurations to use Java 11.
Step 8: Test Applications
Test your applications to ensure they are compatible with Java 11.
Conclusion:
In this blog, we have discussed how to upgrade Java 8 to Java 11 on Ubuntu 20. Java 11 provides several new features and enhancements that make it easier to develop and deploy Java applications. By following the steps outlined in this blog, you can easily upgrade to Java 11 and take advantage of its new features and benefits.
