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The Update List command switches all Java alternatives to automatic mode, allowing the system to select the highest priority version for java, javac, and jar.

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When to use this command

Use this command when you:
  • Want to let the system automatically choose the best Java version
  • Have manually selected a version and want to return to automatic mode
  • Just installed a new Java version with higher priority and want it to become active
  • Need to reset your Java configuration to system defaults
  • Want to ensure all Java binaries use the highest priority version

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How it works

This command uses update-alternatives --auto to switch from manual mode to automatic mode. In auto mode, the system always uses the alternative with the highest priority number.

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Automatic vs manual mode

Manual mode

  • Set when you use Change Version
  • System uses your explicitly selected version
  • Persists even if higher priority versions are installed
  • Remains until you change it or run Update List

Automatic mode

  • Set when you use Update List
  • System uses the highest priority version
  • Automatically updates when new versions are installed
  • Recommended for most users

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Step-by-step usage

1

Select the command

From the main menu, choose “Update List”
2

Automatic update process

The tool switches all three Java binaries to auto mode:
Updating system alternatives
This happens automatically with sudo privileges.
3

Completion

After about 1 second, the screen clears and returns to the main menu. Your Java alternatives are now in auto mode.
4

Verify the change

Check which version is now active:
$ java -version
java version "21.0.1" 2023-10-17 LTS
Java(TM) SE Runtime Environment (build 21.0.1+12-LTS-29)
Java HotSpot(TM) 64-Bit Server VM (build 21.0.1+12-LTS-29, mixed mode, sharing)

$ update-alternatives --display java
java - auto mode
  link best version is /opt/java/jdk-21/bin/java

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What happens behind the scenes

The implementation in internal/commands/updatelistjava.go:11-35 executes three update-alternatives --auto commands: 
err := u.RunCommandInteractive("sudo", "update-alternatives", "--auto", "java")
if err != nil {
    color.Error.Println("Error: ", err)
    return
}

err = u.RunCommandInteractive("sudo", "update-alternatives", "--auto", "javac")
if err != nil {
    color.Error.Println("Error: ", err)
    return
}

err = u.RunCommandInteractive("sudo", "update-alternatives", "--auto", "jar")
if err != nil {
    color.Error.Println("Error: ", err)
    return
}
Each command:
  1. Switches the alternative from manual to auto mode
  2. Evaluates all registered alternatives
  3. Selects the one with the highest priority
  4. Updates the symbolic link in /usr/bin/ to point to the highest priority version

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Priority-based selection

The system selects the Java version based on priority numbers assigned during installation:
PriorityTypical Java Version
800Java 8
1100Java 11
1700Java 17
2100Java 21
Higher numbers = higher priority. If you have Java 11 (priority 1100), Java 17 (priority 1700), and Java 21 (priority 2100) installed, auto mode will select Java 21.

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Real terminal example

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Before running Update List (manual mode)

$ update-alternatives --display java
java - manual mode
  link currently points to /opt/java/jdk-11/bin/java
/opt/java/jdk-11/bin/java - priority 1100
/opt/java/jdk-17/bin/java - priority 1700
/opt/java/jdk-21/bin/java - priority 2100

$ java -version
java version "11.0.21"

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Running Update List

$ javaoptionscli
# Select "Update List" from menu

Updating system alternatives

# Returns to main menu after 1 second

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After running Update List (auto mode)

$ update-alternatives --display java
java - auto mode
  link best version is /opt/java/jdk-21/bin/java
  link currently points to /opt/java/jdk-21/bin/java
/opt/java/jdk-11/bin/java - priority 1100
/opt/java/jdk-17/bin/java - priority 1700
/opt/java/jdk-21/bin/java - priority 2100

$ java -version
java version "21.0.1"

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Common use cases

Automatically switch to the newly installed version:
# Install new Java version
$ javaoptionscli  # New Version Java -> jdk-21.tar.gz (priority 2100)

# Activate it automatically
$ javaoptionscli  # Update List

# Verify
$ java -version  # Now shows Java 21
Return to the highest priority version after testing:
# Temporarily switch to Java 11 for testing
$ javaoptionscli  # Change Version -> Java 11
$ ./run-legacy-tests.sh

# Reset to auto mode (Java 21)
$ javaoptionscli  # Update List
$ java -version  # Back to Java 21
Set up a machine with sensible defaults:
# Install multiple versions
$ javaoptionscli  # New Version Java -> jdk-17 (priority 1700)
$ javaoptionscli  # New Version Java -> jdk-21 (priority 2100)

# Set to auto mode for automatic selection
$ javaoptionscli  # Update List

# System will always use Java 21 unless manually changed
If your java, javac, and jar are using different versions:
$ which java  # Points to Java 21
$ which javac  # Points to Java 17
$ which jar  # Points to Java 11

# Fix by resetting to auto mode
$ javaoptionscli  # Update List

# All three now point to Java 21

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When NOT to use this command

Project-specific version requirementsDon’t use Update List if your current project requires a specific Java version that’s not the highest priority. Instead:
  • Use Change Version to maintain your required version
  • Or adjust priorities during installation so your required version has the highest priority

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Behavior with priority ties

If two versions have the same priority (rare but possible): 
/opt/java/jdk-17-oracle/bin/java - priority 1700
/opt/java/jdk-17-openjdk/bin/java - priority 1700
The system will choose the one that was registered first. To control this:
  • Delete and reinstall with different priorities
  • Or use Change Version to manually select your preferred version

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Checking current mode

To see if you’re in auto or manual mode: 
$ update-alternatives --display java
java - auto mode  # or "manual mode"
  link best version is /opt/java/jdk-21/bin/java
  link currently points to /opt/java/jdk-21/bin/java
...
Or for a quick check: 
$ update-alternatives --query java | grep -i mode
Status: auto

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Comparison with other commands

CommandMode AfterVersion Selection
New Version JavaUnchangedNo change to active version
Change VersionManualYour selection
Update ListAutoHighest priority
Delete VersionUnchangedAuto-adjusts if deleted version was active
Best practice: Use auto mode (Update List) for general development unless you have a specific reason to pin a version. This ensures you’re always using the most recent Java version you’ve installed.

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Troubleshooting

Update List doesn’t change my active version
  • Check priorities: update-alternatives --display java
  • The version you expect may not have the highest priority
  • Use Change Version instead
JAVA_HOME still points to old version
  • update-alternatives doesn’t modify JAVA_HOME
  • Update manually: export JAVA_HOME=/opt/java/jdk-21
  • Add to ~/.bashrc for persistence
Error: update-alternatives: error: no alternatives for java Changes don’t persist after reboot
  • Auto mode persists across reboots
  • If reverting, check startup scripts that might set Java version
  • Look for JAVA_HOME exports in ~/.bashrc, ~/.profile, etc.

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