Expand description
§Hier
Hier is a library supports JVM class hierarchy lookup by extending JNI interface.
§Installation
To use this Hier, you’ll need to have complete installation of JDK
on machine (additionally, environment variables should be set,
e.g. JAVA_HOME).
§Usage
To use without calling from an exist Java application, you’ll need
to enable invocation feature, then use ClassPool::from_permanent_env
to construct a ClassPool.
§Get common super class of 2 classes
use hier::class::Class;
use hier::classpool::ClassPool;
use hier::errors::HierError;
fn main() {
let mut cp = ClassPool::from_permanent_env().unwrap();
let mut integer_class = cp.lookup_class("java.lang.Integer").unwrap();
let mut float_class = cp.lookup_class("java.lang.Float").unwrap();
let mut most_common_superclass =
find_most_common_superclass(&mut cp, &mut integer_class, &mut float_class).unwrap();
println!("{}", most_common_superclass.name(&mut cp).unwrap());
}
fn find_most_common_superclass(
cp: &mut ClassPool,
class1: &mut Class,
class2: &mut Class,
) -> Result<Class, HierError> {
if class2.is_assignable_from(cp, class1)? {
return Ok(class1.clone());
}
if class1.is_assignable_from(cp, class2)? {
return Ok(class2.clone());
}
if class1.is_interface(cp)? || class2.is_interface(cp)? {
return cp.lookup_class("java.lang.Object");
}
let mut cls1 = class1.clone();
while {
cls1 = match cls1.superclass(cp)? {
Some(superclass) => superclass,
None => return Ok(cls1),
};
!cls1.is_assignable_from(cp, class2)?
} {}
Ok(cls1)
}
§Get derived interface of class
use hier::classpool::ClassPool;
fn main() {
let mut cp = ClassPool::from_permanent_env().unwrap();
let mut integer_class = cp.lookup_class("java.lang.Integer").unwrap();
let mut interfaces = integer_class.interfaces(&mut cp).unwrap();
let interface_names = interfaces
.iter_mut()
.map(|interface_class| interface_class.name(&mut cp))
.collect::<Result<Vec<_>, _>>()
.unwrap();
println!("{interface_names:#?}");
}
§License
Hier is licensed under MIT License.
Re-exports§
pub extern crate jni;