"InvalidArgList" even though the arguments are correct? Huh?

[IoIxD]

So I have the following struct:

pub struct BlockBreakEvent<'mc>(
    pub(crate) jni::JNIEnv<'mc>,
    pub(crate) jni::objects::JObject<'mc>,
    pub(crate) (),
    pub(crate) Vec<jni::objects::JObject<'mc>>,
);
impl<'mc> BlockBreakEvent<'mc> {
    // *snip*
    pub fn set_cancelled(mut self, arg0: bool) -> Result<(), Box<dyn std::error::Error>> {
        let val_0 = self
            .0
            .new_object("java/lang/Boolean", "(Z)V", &[arg0.into()])
            .unwrap();
        let _res = self.0.call_method(
            &self.1,
            "setCancelled",
            "(Z)V",
            &[jni::objects::JValueGen::from(&val_0)],
        )?;
        Ok(())
    }
   // *snip*
}

It's bound to a Minecraft plugin and is based on SpigotMC's API. set_cancelled should call org.bukkit.event.block.BlockBreakEvent.setCancelled and pass a voolean into it.

When this executes, though, I get this error:

thread '<unnamed>' panicked at 'Couldn't cancel event: InvalidArgList(TypeSignature { args: [Primitive(Boolean)], ret: Primitive(Void) })', src/lib.rs:6:31

Am I misreading the error? According to Spigot's docs this is exactly what the function takes as an argument list? What am I doing wrong here?

[IoIxD]

I was so tired that I failed to realize that I was looking at the wrong function and had made this post out of impulse. Oops...

[IoIxD]

No, that's not it; new_object requires the return type to void, I had that part right...

[rib]

The setCancelled API takes a primitive boolean (Z) but you are currently passing a java/lang/Boolean object reference.

Hopefully you can pass &[arg0.into()] to setCancelled without calling new_object.