feat: better custom exception handling + related test

Author: zaaarf

macro/src/wrapper.rs

@@ -66,18 +66,9 @@ pub(crate) fn generate_jni_wrapper(attrs: TokenStream, input: TokenStream) -> Re
 			quote::quote! {
 				let ret = match result {
 					Ok(x) => x,
-					Err(e) => match #env_iden.find_class(e.jclass()) {
-						Err(e) => panic!("error throwing Java exception -- failed resolving error class: {e}"),
-						Ok(class) => match #env_iden.new_string(format!("{e:?}")) {
-							Err(e) => panic!("error throwing Java exception --  failed creating error string: {e}"),
-							Ok(msg) => match #env_iden.new_object(class, "(Ljava/lang/String;)V", &[jni::objects::JValueGen::Object(&msg)]) {
-								Err(e) => panic!("error throwing Java exception -- failed creating object: {e}"),
-								Ok(obj) => match #env_iden.throw(jni::objects::JThrowable::from(obj)) {
-									Err(e) => panic!("error throwing Java exception -- failed throwing: {e}"),
-									Ok(_) => return #return_expr,
-								},
-							},
-						},
+					Err(e) => match #env_iden.throw_new(e.jclass(), format!("{e:?}")) {
+						Err(e) => panic!("error throwing Java exception -- failed throwing: {e}"),
+						Ok(_) => return #return_expr
 					}
 				};
 			}

src/test/Cargo.toml

@@ -9,5 +9,7 @@ crate-type = ["cdylib"]
 path = "test.rs"
 
 [dependencies]
+jni-toolbox-macro = { path = "../../macro/" }
 jni-toolbox = { path = "../.." }
 jni = "0.21"
+thiserror = "1"

src/test/java/toolbox/CustomException.java

@@ -0,0 +1,7 @@
+package toolbox;
+
+public class CustomException extends Exception {
+	public CustomException(String msg) {
+		super(msg);
+	}
+}

src/test/java/toolbox/Main.java

@@ -17,6 +17,7 @@ public class Main {
 	static native boolean maybe(String optional);
 	static native String optional(boolean present);
 	static native String raw();
+	static native void throw_error();
 
 	@Test
 	public void argumentsByValue() {
@@ -61,5 +62,9 @@ public void nullableReturn() {
 		assertNull(Main.optional(false));
 		assertEquals(Main.optional(true), "hello world!");
 	}
-	
+
+	@Test
+	public void throwError() {
+		assertThrows(CustomException.class, Main::throw_error);
+	}
 }

src/test/test.rs

@@ -1,4 +1,4 @@
-use jni_toolbox::jni;
+use jni_toolbox::{jni, JniToolboxError};
 
 #[jni(package = "toolbox", class = "Main")]
 fn sum(a: i32, b: i32) -> i32 {
@@ -33,3 +33,18 @@ fn optional(present: bool) -> Option<String> {
 fn raw<'local>(env: &mut jni::JNIEnv<'local>) -> Result<jni::objects::JString<'local>, jni::errors::Error> {
 	env.new_string("hello world!")
 }
+
+#[derive(thiserror::Error, Debug)]
+#[error("some test error")]
+struct CustomError;
+
+impl JniToolboxError for CustomError {
+	fn jclass(&self) -> String {
+		"toolbox/CustomException".to_string()	
+	}
+}
+
+#[jni(package = "toolbox", class = "Main")]
+fn throw_error() -> Result<(), CustomError> {
+	Err(CustomError)
+}