Struct JavaManager 

pub struct JavaManager { /* private fields */ }

Manages multiple Java installations and provides convenient access methods.

The JavaManager struct provides functionality to:

• Store and organize multiple Java installations
• Filter installations by various criteria
• Set default Java installations
• Execute commands with specific Java versions

Examples

use java_manager::{JavaManager, JavaInfo};

fn main() -> java_manager::Result<()> {
    // Create a manager and discover all Java installations
    let mut manager = JavaManager::new();
    manager.discover_installations()?;

    // List all installations
    println!("Found {} Java installations:", manager.len());
    for java in manager.list() {
        println!("  - {}", java);
    }

    // Get Java by version
    if let Some(java_11) = manager.get_by_version(11) {
        println!("Java 11: {}", java_11);
    }

    Ok(())
}

Implementations

impl JavaManager

pub fn new() -> Self

Creates a new empty JavaManager.

Returns

A new JavaManager instance

Examples

use java_manager::JavaManager;

let manager = JavaManager::new();
assert_eq!(manager.len(), 0);

pub fn discover_installations(&mut self) -> Result<()>

Discovers and adds all Java installations on the system.

Returns

• Ok(()) if discovery succeeds
• Err(JavaLocatorError) if an error occurs during discovery

Examples

use java_manager::JavaManager;

fn main() -> java_manager::Result<()> {
    let mut manager = JavaManager::new();
    manager.discover_installations()?;
    println!("Discovered {} Java installations", manager.len());
    Ok(())
}

pub fn add(&mut self, java_info: JavaInfo)

Adds a Java installation to the manager.

Arguments

• java_info - Java installation information to add

Examples

use java_manager::{JavaManager, JavaInfo};

let mut manager = JavaManager::new();
let java_info = JavaInfo::new("java", "/usr/bin/java", "11.0.12", "64-bit", "OpenJDK");
manager.add(java_info);
assert_eq!(manager.len(), 1);

pub fn get(&self, index: usize) -> Option<&JavaInfo>

Gets a Java installation by index.

Arguments

• index - Index of the Java installation to retrieve

Returns

• Some(&JavaInfo) if the index is valid
• None if the index is out of bounds

Examples

use java_manager::JavaManager;

let manager = JavaManager::new();
// Add some installations first...
// let java = manager.get(0);

pub fn get_by_version(&self, version: u32) -> Option<&JavaInfo>

Gets a Java installation by major version.

If multiple installations have the same version, returns the first one.

Arguments

• version - Major version to look for (e.g., 8, 11, 17)

Returns

• Some(&JavaInfo) if a matching installation is found
• None if no installation with the specified version exists

Examples

use java_manager::JavaManager;

let manager = JavaManager::new();
// Discover installations first...
// if let Some(java_11) = manager.get_by_version(11) {
//     println!("Found Java 11: {}", java_11);
// }

pub fn get_all_by_version(&self, version: u32) -> Vec<&JavaInfo>

Gets all Java installations of a specific major version.

Arguments

• version - Major version to look for

Returns

Vector of references to Java installations with the specified version

Examples

use java_manager::JavaManager;

let manager = JavaManager::new();
// Discover installations first...
// let java_11_installations = manager.get_all_by_version(11);
// println!("Found {} Java 11 installations", java_11_installations.len());

pub fn get_default(&self) -> Option<&JavaInfo>

Gets the default Java installation.

Returns

• Some(&JavaInfo) if a default installation is set
• None if no installations exist or no default is set

Examples

use java_manager::JavaManager;

let manager = JavaManager::new();
// Discover installations first...
// if let Some(default_java) = manager.get_default() {
//     println!("Default Java: {}", default_java);
// }

pub fn set_default(&mut self, index: usize) -> bool

Sets the default Java installation by index.

Arguments

• index - Index of the Java installation to set as default

Returns

• true if the index is valid and default was set
• false if the index is out of bounds

Examples

use java_manager::JavaManager;

let mut manager = JavaManager::new();
// Add installations first...
// let success = manager.set_default(0);

pub fn set_default_by_version(&mut self, version: u32) -> bool

Sets the default Java installation by version.

If multiple installations have the same version, sets the first one as default.

Arguments

• version - Major version to set as default

Returns

• true if a matching installation was found and set as default
• false if no installation with the specified version exists

Examples

use java_manager::JavaManager;

let mut manager = JavaManager::new();
// Discover installations first...
// let success = manager.set_default_by_version(11);

pub fn list(&self) -> &Vec<JavaInfo>

Returns a reference to all Java installations.

Returns

Reference to vector of all Java installations

Examples

use java_manager::JavaManager;

let manager = JavaManager::new();
// Discover installations first...
// let all_java = manager.list();
// for java in all_java {
//     println!("{}", java);
// }

pub fn len(&self) -> usize

Returns the number of Java installations in the manager.

Returns

Number of Java installations

Examples

use java_manager::JavaManager;

let manager = JavaManager::new();
assert_eq!(manager.len(), 0);

pub fn is_empty(&self) -> bool

Checks if the manager has any Java installations.

Returns

• true if there are no Java installations
• false if there is at least one Java installation

Examples

use java_manager::JavaManager;

let manager = JavaManager::new();
assert!(manager.is_empty());

pub fn filter_by_supplier(&self, supplier: &str) -> Vec<&JavaInfo>

Filters Java installations by supplier/vendor.

Arguments

• supplier - Supplier name to filter by (case-insensitive)

Returns

Vector of references to Java installations from the specified supplier

Examples

use java_manager::JavaManager;

let manager = JavaManager::new();
// Discover installations first...
// let openjdk_installations = manager.filter_by_supplier("OpenJDK");

pub fn filter_by_architecture(&self, architecture: &str) -> Vec<&JavaInfo>

Filters Java installations by architecture.

Arguments

• architecture - Architecture to filter by (e.g., “64-bit”, “32-bit”)

Returns

Vector of references to Java installations with the specified architecture

Examples

use java_manager::JavaManager;

let manager = JavaManager::new();
// Discover installations first...
// let x64_installations = manager.filter_by_architecture("64-bit");

pub fn execute_default(&self, args: &[&str]) -> Result<String>

Executes a Java command using the default Java installation.

Arguments

• args - Command-line arguments to pass to Java

Returns

• Ok(String) - Command output as a string
• Err(std::io::Error) - If the command fails to execute or no default Java is set

Examples

use java_manager::JavaManager;

fn main() -> std::io::Result<()> {
    let mut manager = JavaManager::new();
    manager.discover_installations()?;
     
    let output = manager.execute_default(&["-version"])?;
    println!("Output:\n{}", output);
    Ok(())
}

pub fn execute_with_version( &self, version: u32, args: &[&str], ) -> Result<String>

Executes a Java command using a specific Java version.

Arguments

• version - Major version of Java to use
• args - Command-line arguments to pass to Java

Returns

• Ok(String) - Command output as a string
• Err(std::io::Error) - If the command fails to execute or the version is not found

Examples

use java_manager::JavaManager;

fn main() -> std::io::Result<()> {
    let mut manager = JavaManager::new();
    manager.discover_installations()?;
     
    let output = manager.execute_with_version(11, &["-version"])?;
    println!("Java 11 output:\n{}", output);
    Ok(())
}

pub fn get_version_summary(&self) -> HashMap<u32, usize>

Returns a summary of Java installations by version.

Returns

HashMap mapping major versions to counts of installations

Examples

use java_manager::JavaManager;

let manager = JavaManager::new();
// Discover installations first...
// let summary = manager.get_version_summary();
// for (version, count) in summary {
//     println!("Java {}: {} installations", version, count);
// }

pub fn clear(&mut self)

Clears all Java installations from the manager.

Examples

use java_manager::JavaManager;

let mut manager = JavaManager::new();
// Add some installations...
manager.clear();
assert!(manager.is_empty());

Trait Implementations

impl Default for JavaManager

fn default() -> Self

Creates a new JavaManager with default settings.

Returns

A new JavaManager instance