Module robusta_jni::convert

Conversion facilities. This module provides two trait families: FromJavaValue/IntoJavaValue (infallible conversions) and TryFromJavaValue/TryIntoJavaValue (fallible conversions), similar to the ones found in the standard library.

The call_type attribute controls which of the two conversion families is selected during code generation. call_type is a per-function attribute. Specific parameters that can be given to call_type can be found in the module documentation relative to the trait family (safe module for fallible conversions and unchecked module for infallible conversions)

If the call_type attribute is omitted, the fallible conversion trait family is chosen.

Example usage:

use robusta_jni::bridge;

#[bridge]
mod jni {
    #[package(com.example.robusta)]
    struct HelloWorld;

    impl HelloWorld {
        #[call_type(unchecked)]
        pub extern "jni" fn special(mut input1: Vec<i32>, input2: i32) -> Vec<String> {
            input1.push(input2);
            input1.iter().map(ToString::to_string).collect()
        }

        #[call_type(safe(exception_class = "java.lang.IllegalArgumentException", message = "invalid value"))]
        pub extern "jni" fn bar(foo: i32) -> ::robusta_jni::jni::errors::Result<i32> { Ok(foo) }
    }
}

Raising exceptions from native code

If you want to have the option of throwing a Java exception from native code (conversion errors aside), you can annotate your function signature with a jni::errors::Result<T> return type.

When used with #[call_type(safe)], if an Err is returned a Java exception is thrown (the one specified in the call_type attribute, or java.lang.RuntimeException if omitted).

Re-exports

pub use safe::*;

pub use unchecked::*;

pub use field::*;

Modules

field

safe

Fallible conversions traits.

unchecked

Infallible conversion traits.

Structs

JValueWrapper

Traits

JavaValue

A trait for types that are ffi-safe to use with JNI. It is implemented for primitives, JObject and jobject. Users that want automatic conversion should instead implement FromJavaValue, IntoJavaValue and/or TryFromJavaValue, TryIntoJavaValue

Signature

This trait provides type signatures for types. It is necessary to support conversions to/from Java types.

Derive Macros

Signature