Crate ristretto_classloader 

Ristretto ClassLoader

Getting Started

Implementation of a JVM Class Loader that is used to load Java classes. Classes can be loaded from the file system or from a URL; jar and modules are supported. A runtime Java class loader can be created from a LTS version of AWS Corretto. The runtime class loader will download and install the requested version of Corretto and create a class loader that can be used to load Java classes.

The AWS Corretto runtime is installed in the following directory:

• Unix: $HOME/.ristretto/<version>
• Windows: %USERPROFILE%\.ristretto\<version>

Examples

use ristretto_classloader::{runtime, ClassLoader, Result};
use std::sync::Arc;

#[tokio::main]
async fn main() -> Result<()> {
    let (_java_home, java_version, class_loader) = runtime::version_class_loader("21").await?;
    let class_name = "java.util.HashMap";
    println!("Loading {class_name} from Java version {java_version}");
    let class = class_loader.load(class_name).await?;
    println!("{class:?}");
    Ok(())
}

Feature flags

The following features are available:

Name	Description	Default?
url	Enables url class path entries	No

Safety

This crate uses #![forbid(unsafe_code)] to ensure everything is implemented in 100% safe Rust.

Re-exports

pub use runtime::DEFAULT_JAVA_VERSION;

Modules

manifest

runtime

Structs

Class

A representation of a Java class.

ClassLoader

Implementation of a Java class loader.

ClassPath

Represents a class path.

Field

FieldAccessFlags

Field access flags used in Java class files to specify the access permissions and properties of fields.

Manifest

Represents a Jar manifest. See: https://docs.oracle.com/en/java/javase/22/docs/specs/jar/jar.html#jar-manifest

Method

MethodAccessFlags

Method access flags used in Java class files to specify the access permissions and properties of methods.

Object

Represents an object in the Ristretto VM.

ObjectArray

Represents an array of objects in the Ristretto VM.

Enums

BaseType

Represents the primitive types in the Java Virtual Machine.

ClassPathEntry

Represents a class path entry.

Error

Errors that can occur when loading classes

FieldType

Represents a Java field type descriptor as defined in the JVM specification.

Reference

Represents a reference to an object in the Ristretto VM.

Value

Represents a value in the Ristretto VM.

Type Aliases

Result

Ristretto classloader result type