Struct jni::objects::JStaticFieldID

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

Wrapper around jfieldID that implements Send + Sync since field 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 jfieldID.

Safety

According to the JNI spec field 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 JStaticFieldID

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

Creates a JStaticFieldID that wraps the given raw jfieldID

Safety

Expects a valid, non-null ID

pub fn into_raw(self) -> jfieldID

Unwrap to the internal jni type.

Trait Implementations

impl AsMut<JStaticFieldID> for JStaticFieldID

fn as_mut(&mut self) -> &mut JStaticFieldID

Converts this type into a mutable reference of the (usually inferred) input type.

impl AsRef<JStaticFieldID> for JStaticFieldID

fn as_ref(&self) -> &JStaticFieldID

Converts this type into a shared reference of the (usually inferred) input type.

impl Clone for JStaticFieldID

fn clone(&self) -> JStaticFieldID

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for JStaticFieldID

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

Formats the value using the given formatter.

impl<'local, 'other_local, T, U, V> Desc<'local, JStaticFieldID> for (T, U, V)where T: Desc<'local, JClass<'other_local>>, U: Into<JNIString>, V: Into<JNIString>,

type Output = JStaticFieldID

The type that this Desc returns.

fn lookup(self, env: &mut JNIEnv<'local>) -> Result<Self::Output>

Look up the concrete type from the JVM.

impl Copy for JStaticFieldID

impl Send for JStaticFieldID

impl Sync for JStaticFieldID