Struct jni_glue::Local

pub struct Local<'env, Class: AsValidJObjectAndEnv> { /* fields omitted */ }

A Local, non-null, reference to a Java object (+ &Env) limited to the current thread/stack.

Including the env allows for the convenient execution of methods without having to individually pass the env as an argument to each and every one. Since this is limited to the current thread/stack, these cannot be sanely stored in any kind of static storage, nor shared between threads - instead use a Global if you need to do either.

Will DeleteLocalRef when dropped, invalidating the jobject but ensuring threads that rarely or never return to Java may run without being guaranteed to eventually exhaust their local reference limit. If this is not desired, convert to a plain Ref with:

let local = Local::leak(local);

Not FFI Safe: #[repr(rust)], and exact layout is likely to change - depending on exact features used - in the future. Specifically, on Android, since we're guaranteed to only have a single ambient VM, we can likely store the *const JNIEnv in thread local storage instead of lugging it around in every Local. Of course, there's no guarantee that's actually an optimization...

Methods

impl<'env, Class: AsValidJObjectAndEnv> Local<'env, Class>

pub unsafe fn from_env_object(env: *const JNIEnv, object: jobject) -> Self

pub fn leak(local: Self) -> Ref<'env, Class>

Trait Implementations

impl<'env, Class: AsValidJObjectAndEnv + Debug> Debug for Local<'env, Class>

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

Formats the value using the given formatter.

impl<'env, Class: AsValidJObjectAndEnv> Deref for Local<'env, Class>

type Target = Class

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<'env, Class: AsValidJObjectAndEnv + Display> Display for Local<'env, Class>

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

Formats the value using the given formatter.

impl<'env, Class: AsValidJObjectAndEnv> Drop for Local<'env, Class>

fn drop(&mut self)

Executes the destructor for this type.

impl<'env, Class: AsValidJObjectAndEnv> From<Local<'env, Class>> for Global<Class>

fn from(local: Local<'env, Class>) -> Global<Class>

Performs the conversion.