在GraalVM中从Java调用wasm代码时如何使用回调

跟随 我尝试使用回调返回到Java代码中

编译成

示例.wasm

：

#[无损坏]
酒吧外间fn问候（打印：外间fn（u8））{
印刷品（42）
}

使用GraalVM polyglot API嵌入WASM的Java代码：

byte[]binary=readBytes（“example.wasm”）；
Context.Builder contextBuilder=Context.newBuilder（“wasm”）；
Source.Builder sourceBuilder=Source.newBuilder（“wasm”，ByteSequence.create（二进制），“example”）；
Source=sourceBuilder.build（）；
Context=contextBuilder.build（）；
context.eval（来源）；
消费者打印=（Value val）->System.out.println（“调用的回调：“+val”）；
Value greetFunction=context.getBindings（“wasm”）.getMember（“main”）.getMember（“greet”）；
greetFunction.execute（打印）；

但是，运行此程序时，我会遇到以下异常：

Exception in thread "main" java.lang.reflect.InvocationTargetException
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:49)
    at org.springframework.boot.loader.Launcher.launch(Launcher.java:108)
    at org.springframework.boot.loader.Launcher.launch(Launcher.java:58)
    at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:88)
Caused by: org.graalvm.polyglot.PolyglotException: java.lang.ClassCastException: class com.oracle.truffle.polyglot.HostObject cannot be cast to class java.lang.Integer (com.oracle.truffle.polyglot.HostObject is in module org.graalvm.truffle of loader 'app'; java.lang.Integer is in module java.base of loader 'bootstrap')
    at org.graalvm.wasm.nodes.WasmRootNode.moveArgumentsToLocals(WasmRootNode.java:173)
    at org.graalvm.wasm.nodes.WasmRootNode.executeWithContext(WasmRootNode.java:122)
    at org.graalvm.wasm.nodes.WasmRootNode.execute(WasmRootNode.java:103)
    at <wasm>.greet(Unknown)
    at org.graalvm.sdk/org.graalvm.polyglot.Value.execute(Value.java:834)
    at org.example.wasmhost.WasmHostApplication.main(WasmHostApplication.java:57)
    ... 8 more

$ java -version
openjdk version "11.0.11" 2021-04-20
OpenJDK Runtime Environment GraalVM CE 21.1.0 (build 11.0.11+8-jvmci-21.1-b05)
OpenJDK 64-Bit Server VM GraalVM CE 21.1.0 (build 11.0.11+8-jvmci-21.1-b05, mixed mode, sharing)