Struct JavaRuntime

pub struct JavaRuntime { /* private fields */ }

Struct JavaRuntime Represents a java runtime in specific path.

To detect java runtimes from specific path, see detector

Implementations

impl JavaRuntime

pub fn from_executable(path: &Path) -> Result<Self, Error>

Create a JavaRuntime object from the path of java executable file

It executes command java -version to get the version information

Parameters

• path Path to java executable file.

Examples

use java_runtimes::JavaRuntime;

let _ = JavaRuntime::from_executable(r"D:\java\jdk-17.0.4.1\bin\java.exe".as_ref());
let _ = JavaRuntime::from_executable(r"../../runtimes/jdk-1.8.0_291/bin/java".as_ref());

pub fn new(os: &str, path: &Path, version_string: &str) -> Result<Self, Error>

Mannually create a JavaRuntime instance, without checking if it’s available

Parameters

• os Got from env::consts::OS
• path The path of java executable file, can be either relative or absolute
• version_string can be like "17.0.4.1" or the output of command java -version

Examples

use java_runtimes::JavaRuntime;
use std::env;
use std::path::Path;

let java_exe_path = Path::new("../java/jdk-17.0.4.1/bin/java");
let version_outputs = r#"java version "17.0.4.1" 2022-08-18 LTS
Java(TM) SE Runtime Environment (build 17.0.4.1+1-LTS-2)
Java HotSpot(TM) 64-Bit Server VM (build 17.0.4.1+1-LTS-2, mixed mode, sharing)
"#;
let runtime = JavaRuntime::new(env::consts::OS, java_exe_path, version_outputs).unwrap();
assert_eq!(runtime.get_version_string(), "17.0.4.1");
assert!(runtime.is_same_os());

pub fn get_os(&self) -> &str

Get the operating system of the java runtime

The os string comes from env::consts::OS when this object was created.

pub fn is_windows(&self) -> bool

pub fn get_executable(&self) -> &Path

Get the path of java executable file

It can be absolute or relative, depends on how you created it.

Examples

• D:\Java\jdk-17.0.4.1\bin\java.exe (Windows, absolute)
• ../../runtimes/jdk-1.8.0_291/bin/java (Linux, relative)

pub fn has_root(&self) -> bool

Returns true if the Path has a root.

Refer to Path::has_root

Examples

use java_runtimes::JavaRuntime;

let runtime = JavaRuntime::new("linux", "/jdk/bin/java".as_ref(), "21.0.3").unwrap();
assert!(runtime.has_root());

let runtime = JavaRuntime::new("windows", r"D:\jdk\bin\java.exe".as_ref(), "21.0.3").unwrap();
assert!(runtime.has_root());

let runtime = JavaRuntime::new("linux", "../jdk/bin/java".as_ref(), "21.0.3").unwrap();
assert!(!runtime.has_root());

let runtime = JavaRuntime::new("windows", r"..\jdk\bin\java.exe".as_ref(), "21.0.3").unwrap();
assert!(!runtime.has_root());

pub fn get_version_string(&self) -> &str

Get the version string

Examples

use java_runtimes::JavaRuntime;

let runtime = JavaRuntime::new("linux", "/jdk/bin/java".as_ref(), "21.0.3").unwrap();
assert_eq!(runtime.get_version_string(), "21.0.3");

pub fn is_same_os(&self) -> bool

Check if this is the same os as current

pub fn to_absolute(&self) -> Result<Self, Error>

Create a new JavaRuntime with absolute path.

Errors

Returns an Err if the current working directory value is invalid. Refer to env::current_dir

Possible cases:

• Current directory does not exist.
• There are insufficient permissions to access the current directory.

pub fn update(&mut self) -> Result<(), Error>

Try executing java -version and parse the output to get the version.

If success, it will update the version value in this JavaRuntime instance.

pub fn is_available(&self) -> bool

Test if this runtime is available currently

It executes command java -version to see if it works

pub fn extract_version(version_string: &str) -> Result<String, Error>

Parse version string

Return

(version_string, version_major)

Examples

use java_runtimes::JavaRuntime;

assert_eq!(JavaRuntime::extract_version("1.8.0_333").unwrap(), "1.8.0_333");
assert_eq!(JavaRuntime::extract_version("17.0.4.1").unwrap(), "17.0.4.1");
assert_eq!(JavaRuntime::extract_version("\"17.0.4.1").unwrap(), "17.0.4.1");
assert_eq!(JavaRuntime::extract_version("java version \"17.0.4.1\"").unwrap(), "17.0.4.1");

Trait Implementations

impl Clone for JavaRuntime

fn clone(&self) -> Self

Examples

use java_runtimes::JavaRuntime;

let r1 = JavaRuntime::new("linux", "/jdk/bin/java".as_ref(), "21.0.3").unwrap();
let r2 = r1.clone();

assert_eq!(r1, r2);

fn clone_from(&mut self, source: &Self)

Examples

use java_runtimes::JavaRuntime;

let mut r1 = JavaRuntime::new("windows", "/jdk/bin/java".as_ref(), "21.0.3").unwrap();
let r2 = JavaRuntime::new("windows", r"D:\jdk\bin\java.exe".as_ref(), "21.0.3").unwrap();

r1.clone_from(&r2);
assert_eq!(r1, r2);

impl Debug for JavaRuntime

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for JavaRuntime

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for JavaRuntime

fn eq(&self, other: &Self) -> bool

Examples

use java_runtimes::JavaRuntime;

let r1 = JavaRuntime::new("linux", "/jdk/bin/java".as_ref(), "21.0.3").unwrap();
let r2 = JavaRuntime::new("linux", "/jdk/bin/java".as_ref(), "21.0.3").unwrap();
let r3 = JavaRuntime::new("windows", r"D:\jdk\bin\java.exe".as_ref(), "21.0.3").unwrap();
let r4 = JavaRuntime::new("windows", r"D:\jdk-17\bin\java.exe".as_ref(), "21.0.3").unwrap();

assert_eq!(r1, r2);
assert_ne!(r1, r3);
assert_ne!(r2, r3);
assert_ne!(r2, r4);
assert_ne!(r3, r4);

fn ne(&self, other: &Self) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for JavaRuntime

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.