英文:
Why do I get a WrongMethodTypeException on invokeExact even though MethodHandle is OK
问题
以下是翻译好的部分：
我正试图调用一个invoke方法，但有一个错误我无法解释。
我听说Invoke Exact方法必须返回，但即使那样也不起作用。
在这段代码中，程序崩溃了。
这是包含我想要调用的方法的类。
s.loadMessageExchanger(new ServerMessageExchanger() {
@TrafficID(id = "cords")
public Boolean setCords(ChannelHandlerContext ctx, ByteBuf byteBuf) {
System.out.println("jaaa");
return true;
}
});
以上是您提供的内容的翻译。如果您还有其他疑问或需要进一步的帮助，请随时问我。
英文:
I am trying to call an invoke method and there is an error that I cannot explain.
I have heard that the Invoke Exact method has to return but it did not work even then.
public boolean exec(String id, ChannelHandlerContext ctx, ByteBuf byteBuf) {
assert ctx != null;
assert byteBuf != null;
MethodHandle methodHandle = this.idMethods.get(id);
if(methodHandle != null) {
try {
Object object = this.idObjects.get(id);
Boolean b = (Boolean) methodHandle.invokeExact(object, ctx, byteBuf);
return true;
} catch (Throwable throwable) {
throwable.printStackTrace();
}
}
return false;
}
on this code the Programm crash
Boolean b = (Boolean) methodHandle.invokeExact(object, ctx, byteBuf);
java.lang.invoke.WrongMethodTypeException: expected (,ChannelHandlerContext,ByteBuf)boolean but found (Object,ChannelHandlerContext,ByteBuf)Boolean
at java.lang.invoke.Invokers.newWrongMethodTypeException(Invokers.java:298)
at java.lang.invoke.Invokers.checkExactType(Invokers.java:309)
at de.moldiy.molnet.MessageExchangerManager.exec(MessageExchangerManager.java:54)
at de.moldiy.molnet.MessageHandler.channelRead0(MessageHandler.java:22)
at de.moldiy.molnet.MessageHandler.channelRead0(MessageHandler.java:7)
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:99)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:324)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:296)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:714)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:650)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:576)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.lang.Thread.run(Thread.java:836)
This is the class that contains the method I want to call
s.loadMessageExchanger(new ServerMessageExchanger() {
@TrafficID(id = "cords")
public Boolean setCords(ChannelHandlerContext ctx,ByteBuf byteBuf) {
System.out.println("jaaa");
return true;
}
});
答案1
得分: 2
因为您正在调用ServerMessageExchanger实例上的方法，所以您需要将该实例作为第一个参数传递给MethodHandle.invokeExact。
类似这样：
ServerMessageExchanger sme;
....
MethodHandle methodHandle = this.methods.get(id);
Boolean b = (Boolean) methodHandle.invokeExact(sme, ctx, byteBuf);
英文:
Since you are invoking a method on an instance of ServerMessageExchanger, you need to pass that instance as the first argument to MethodHandle.invokeExact.
Something like this:
ServerMessageExchanger sme;
....
MethodHandle methodHandle = this.methods.get(id);
Boolean b = (Boolean) methodHandle.invokeExact(sme, ctx, byteBuf);
答案2
得分: 0
我现在知道问题出在哪里了，使用invokeExact时无法定义匿名类，因为类型必须从一开始就知道，所以这是不可能的：
Object object = this.idObjects.get(id);
methodHandle.invokeExact(object, ctx, byteBuf);
但是我可以使用invoke来替代：
Object object = this.idObjects.get(id);
methodHandle.invoke(object, ctx, byteBuf);
英文:
i know now what was wrong, with invokeExact you can't define an anonymous class because the types have to be known from the beginning, so this is not possible:
Object object = this.idObjects.get(id);
methodHandle.invokeExact(object, ctx, byteBuf);
But I can just use invoke:
Object object = this.idObjects.get(id);
methodHandle.invoke(object, ctx, byteBuf);
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