Struct jni::objects::JMethodID

#[repr(transparent)]
pub struct JMethodID { /* private fields */ }

Wrapper around jmethodID that implements Send + Sync since method IDs are valid across threads (not tied to a JNIEnv).

There is no lifetime associated with these since they aren’t garbage collected like objects and their lifetime is not implicitly connected with the scope in which they are queried.

It matches C’s representation of the raw pointer, so it can be used in any of the extern function argument positions that would take a jmethodID.

Safety

According to the JNI spec method IDs may be invalidated when the corresponding class is unloaded.

Since this constraint can’t be encoded as a Rust lifetime, and to avoid the excessive cost of having every Method ID be associated with a global reference to the corresponding class then it is the developers responsibility to ensure they hold some class reference for the lifetime of cached method IDs.

Implementations

impl JMethodID

pub unsafe fn from_raw(raw: jmethodID) -> Self

Creates a JMethodID that wraps the given raw jmethodID

Safety

Expects a valid, non-null ID

pub fn into_raw(self) -> jmethodID

Unwrap to the internal jni type.

Trait Implementations

impl Clone for JMethodID

fn clone(&self) -> JMethodID

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for JMethodID

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

Formats the value using the given formatter.

impl<'a, 'c, T, Signature> Desc<'a, JMethodID> for (T, Signature)where
    T: Desc<'a, JClass<'c>>,
    Signature: Into<JNIString>,

fn lookup(self, env: &JNIEnv<'a>) -> Result<JMethodID>

Look up the concrete type from the JVM.

impl<'a, 'c, T, U, V> Desc<'a, JMethodID> for (T, U, V)where
    T: Desc<'a, JClass<'c>>,
    U: Into<JNIString>,
    V: Into<JNIString>,

fn lookup(self, env: &JNIEnv<'a>) -> Result<JMethodID>

Look up the concrete type from the JVM.

impl Copy for JMethodID

impl Send for JMethodID

impl Sync for JMethodID