Current limitations
Debian-based systems only
JavaOptionsCli has only been tested on Debian-based Linux distributions (Ubuntu, Debian, Linux Mint, etc.).
Why: The tool relies heavily on the update-alternatives system, which is specific to Debian-based distributions.
Impact: Users on other Linux distributions (Fedora, Arch, openSUSE) cannot use this tool without modifications.
# Required for JavaOptionsCli
sudo update-alternatives --install ...
sudo update-alternatives --config ...
Requires update-alternatives
The tool assumes that update-alternatives is available on the system.
What it’s used for:
- Registering Java installations
- Switching between Java versions
- Managing system-wide Java, javac, and jar binaries
If update-alternatives is not available, the CLI will fail when attempting to register or manage Java versions.
Must run from tar directory
The CLI must be executed from the same directory as your .tar.gz file when installing a new Java version.
- Extracts the tar.gz file in the current working directory
- Uses
filepath.Glob("jdk-*") to find the extracted folder
- Moves the folder to
/opt/java
Code reference (internal/helps/helps.go:79-90):
func ExtractNameDir() []string {
matches, err := filepath.Glob("jdk-*")
if err != nil {
log.Fatal(err)
}
if len(matches) == 0 {
log.Fatal("not found")
}
return matches
}
# Even with JavaOptionsCli in PATH:
cd ~/downloads
JavaOptionsCli # Now install from here
Fixed installation path
All Java versions are installed to /opt/java with no option to customize the location.
Hardcoded path (internal/commands/newjava.go:24-29):
info, err := os.Stat("/opt/java")
helps.ExistDir(info, err)
helps.ExtracFile(tar)
maches := helps.ExtractNameDir()
pathF := "/opt/java/" + maches[0]
No automatic downloading
Users must manually download Java tar.gz files from Oracle, Adoptium, or other sources before using the CLI.
Current workflow:
- Download
.tar.gz from external source
- Place in a directory
- Run CLI from that directory
- Enter filename when prompted
Limited version detection
The tool relies on user input for:
- The folder name within
/opt/java
- The priority number for update-alternatives
There’s no automatic parsing of the Java version from the archive or java -version output.
Single binary registration
Only three binaries are registered with update-alternatives:
Other Java tools in the bin directory (like jshell, keytool, jdeps) are not automatically registered.
Future improvements
The following enhancements are planned for future releases:
Support for other Linux distributions
Expand compatibility beyond Debian-based systems by:
- Detecting the distribution type
- Implementing alternative version management for RPM-based systems
- Supporting generic installation methods
Automatic download of Java releases
Integrate direct downloading capabilities:
- Fetch Java releases from Adoptium, Oracle, or other sources
- Verify checksums for security
- Eliminate the need for manual downloads
Potential workflow:
JavaOptionsCli
> Install new Java version
> Select: Java 21 (Temurin)
> Downloading...
> Installing...
Better version detection
Automatic detection of:
- Java version from archive contents
- Vendor information (Oracle, Adoptium, etc.)
- Appropriate priority values
- All available binaries in the distribution
Configurable install path
Allow users to specify custom installation directories:
# Potential configuration
~/.javaoptionscli/config.yaml
install_path: /opt/java
# or
install_path: /home/user/.local/java
- Accept full paths to tar.gz files
- Extract to temporary location
- Move to final destination
Potential usage:
JavaOptionsCli install /path/to/jdk-21_linux-x64_bin.tar.gz