Java JNA函数指针作为结构字段

我有一个以函数指针作为字段的结构定义：

我这样定义了一个JNA结构

package com.dewdropgames.chipmunk2djna.structs;

import com.dewdropgames.chipmunk2djna.CpVect;
import com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc;
import com.sun.jna.Structure;

import java.util.Arrays;
import java.util.List;

public class CpBody extends Structure {
    private static final List<String> FIELD_ORDER = Arrays.asList(
/// ...
            "position_func",
/// ...
    );

    @Override
    protected List getFieldOrder() {
        return FIELD_ORDER;
    }

    public static class ByReference 
        extends CpBody 
        implements Structure.ByReference{};

// ...
    public CpBodyPositionFunc position_func;
// ...

但当我运行这段代码时，有一个例外：

Caused by: java.lang.IllegalArgumentException: 
The type "com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc"
is not supported: 
Native size for type
"com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc" 
is unknown

我做错了什么？顺便说一句，如果我只定义了

Pointer

这样的字段，并且从未尝试调用它们，那么行为正常

堆栈跟踪：

:runAppException in thread "main" java.lang.IllegalArgumentException: Invalid Structure field in class com.dewdropgames.chipmunk2djna.structs.CpSpace$ByReference, field name '_staticBody' (class com.dewdropgames.chipmunk2djna.structs.CpBody): Invalid Structure field in class com.dewdropgames.chipmunk2djna.structs.CpBody, field name 'position_func' (interface com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc): The type "com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc" is not supported: Native size for type "com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc" is unknown
        at com.sun.jna.Structure.validateField(Structure.java:1109)
        at com.sun.jna.Structure.validateFields(Structure.java:1119)
        at com.sun.jna.Structure.<init>(Structure.java:179)
        at com.sun.jna.Structure.<init>(Structure.java:172)
        at com.sun.jna.Structure.<init>(Structure.java:159)
        at com.sun.jna.Structure.<init>(Structure.java:151)
        at com.dewdropgames.chipmunk2djna.structs.CpSpace.<init>(CpSpace.java:13)
        at com.dewdropgames.chipmunk2djna.structs.CpSpace$ByReference.<init>(CpSpace.java:54)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
        at java.lang.Class.newInstance(Class.java:442)
        at com.sun.jna.Structure.newInstance(Structure.java:1773)
        at com.sun.jna.Structure.newInstance(Structure.java:1759)
        at com.sun.jna.Function.invoke(Function.java:424)
        at com.sun.jna.Function.invoke(Function.java:323)
        at com.sun.jna.Library$Handler.invoke(Library.java:236)
        at com.sun.proxy.$Proxy0.cpSpaceNew(Unknown Source)
        at com.dewdropgames.chipmunk2djna.FirstTry.main(FirstTry.java:31)
Caused by: java.lang.IllegalArgumentException: Invalid Structure field in class com.dewdropgames.chipmunk2djna.structs.CpBody, field name 'position_func' (interface com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc): The type "com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc" is not supported: Native size for type "com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc" is unknown

Initializing cpSpace - Chipmunk v7.0.1 (Debug Enabled)
Compile with -DNDEBUG defined to disable debug mode and runtime assertion checks
        at com.sun.jna.Structure.validateField(Structure.java:1109)
        at com.sun.jna.Structure.validateFields(Structure.java:1119)
        at com.sun.jna.Structure.<init>(Structure.java:179)
        at com.sun.jna.Structure.<init>(Structure.java:172)
        at com.sun.jna.Structure.<init>(Structure.java:159)
        at com.sun.jna.Structure.<init>(Structure.java:151)
        at com.dewdropgames.chipmunk2djna.structs.CpBody.<init>(CpBody.java:15)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
        at java.lang.Class.newInstance(Class.java:442)
        at com.sun.jna.Structure.newInstance(Structure.java:1773)
        at com.sun.jna.Structure.newInstance(Structure.java:1759)
        at com.sun.jna.Structure.size(Structure.java:1030)
        at com.sun.jna.Native.getNativeSize(Native.java:1172)
        at com.sun.jna.Structure.getNativeSize(Structure.java:2072)
        at com.sun.jna.Structure.getNativeSize(Structure.java:2062)
        at com.sun.jna.Structure.validateField(Structure.java:1105)
        ... 19 more
Caused by: java.lang.IllegalArgumentException: The type "com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc" is not supported: Native size for type "com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc" is unknown
        at com.sun.jna.Native.getNativeSize(Native.java:1180)
        at com.sun.jna.Structure.getNativeSize(Structure.java:2072)
        at com.sun.jna.Structure.getNativeSize(Structure.java:2062)
        at com.sun.jna.Structure.validateField(Structure.java:1105)
        ... 37 more

：线程“main”java.lang.IllegalArgumentException中的runAppException:类com.dewdropgames.chipmunk2djna.structs.CpSpace$ByReference中的结构字段无效，字段名“_staticBody”（类com.dewdropgames.chipmunk2djna.structs.CpBody）：类com.dewdropgames.chipmunk2djna.structs.CpBody中的结构字段无效，字段名“position_func”（接口com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc）：不支持类型“com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc”：类型“com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc”的本机大小未知
位于com.sun.jna.Structure.validateField（Structure.java:1109）
位于com.sun.jna.Structure.validateFields（Structure.java:1119）
位于com.sun.jna.Structure.（Structure.java:179）
位于com.sun.jna.Structure.（Structure.java:172）
位于com.sun.jna.Structure.（Structure.java:159）
位于com.sun.jna.Structure.（Structure.java:151）
在com.dewdropgames.chipmunk2djna.structs.CpSpace.（CpSpace.java:13）
在com.dewdropgames.chipmunk2djna.structs.CpSpace$ByReference.（CpSpace.java:54）
位于sun.reflect.NativeConstructorAccessorImpl.newInstance0（本机方法）
位于sun.reflect.NativeConstructorAccessorImpl.newInstance（NativeConstructorAccessorImpl.java:62）
在sun.reflect.DelegatingConstructorAccessorImpl.newInstance（DelegatingConstructorAccessorImpl.java:45）
位于java.lang.reflect.Constructor.newInstance（Constructor.java:422）
位于java.lang.Class.newInstance（Class.java:442）
位于com.sun.jna.Structure.newInstance（Structure.java:1773）
位于com.sun.jna.Structure.newInstance（Structure.java:1759）
位于com.sun.jna.Function.invoke（Function.java:424）
位于com.sun.jna.Function.invoke（Function.java:323）
位于com.sun.jna.Library$Handler.invoke（Library.java:236）
位于com.sun.proxy.$Proxy0.cpSpaceNew（未知源）
位于com.dewdropgames.chipmunk2djna.FirstTry.main（FirstTry.java:31）
原因：java.lang.IllegalArgumentException:类com.dewdropgames.chipmunk2djna.structs.CpBody中的结构字段无效，字段名“position_func”（接口com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc）：不支持类型“com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc”：类型的本机大小“com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc”未知
初始化cpSpace-花栗鼠v7.0.1（已启用调试）
使用定义为禁用调试模式和运行时断言检查的-DNDEBUG进行编译
位于com.sun.jna.Structure.validateField（Structure.java:1109）
位于com.sun.jna.Structure.validateFields（Structure.java:1119）
位于com.sun.jna.Structure.（Structure.java:179）
位于com.sun.jna.Structure.（Structure.java:172）
位于com.sun.jna.Structure.（Structure.java:159）
位于com.sun.jna.Structure.（Structure.java:151）
在com.dewdropgames.chipmunk2djna.structs.CpBody上（CpBody.java:15）
位于sun.reflect.NativeConstructorAccessorImpl.newInstance0（本机方法）
位于sun.reflect.NativeConstructorAccessorImpl.newInstance（NativeConstructorAccessorImpl.java:62）
在sun.reflect.DelegatingConstructorAccessorImpl.newInstance（DelegatingConstructorAccessorImpl.java:45）
位于java.lang.reflect.Constructor.newInstance（Constructor.java:422）
位于java.lang.Class.newInstance（Class.java:442）
位于com.sun.jna.Structure.newInstance（Structure.java:1773）
位于com.sun.jna.Structure.newInstance（Structure.java:1759）
位于com.sun.jna.Structure.size（Structure.java:1030）
位于com.sun.jna.Native.getNativeSize（Native.java:1172）
位于com.sun.jna.Structure.getNativeSize（Structure.java:2072）
位于com.sun.jna.Structure.getNativeSize（Structure.java:2062）
位于com.sun.jna.Structure.validateField（Structure.java:1105）
…还有19个
原因：java.lang.IllegalArgumentException:不支持类型“com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc”：类型“com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc”的本机大小未知
位于com.sun.jna.Native.getNativeSize（Native.java:1180）
位于com.sun.jna.Structure.getNativeSize（Structure.java:2072）
位于com.sun.jna.Structure.getNativeSize（Structure.java:2062）
位于com.sun.jna.Structure.validateField（Structure.java:1105）
…还有37个

事实上，这次半自动导入失败了，导入了另一个接口，发现这行：

导入javax.security.auth.callback.callback；

---

本机函数的JNA接口应实现

com.sun.JNA.Callback

您的类型似乎未被识别为

com.sun.JNA.Callback

的实现。请包含完整的堆栈跟踪。完成后，请查看帖子下方的堆栈跟踪。确保您导入了

com.sun.JNA.Callback

给我另一个名为

Callback

的类。

:runAppException in thread "main" java.lang.IllegalArgumentException: Invalid Structure field in class com.dewdropgames.chipmunk2djna.structs.CpSpace$ByReference, field name '_staticBody' (class com.dewdropgames.chipmunk2djna.structs.CpBody): Invalid Structure field in class com.dewdropgames.chipmunk2djna.structs.CpBody, field name 'position_func' (interface com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc): The type "com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc" is not supported: Native size for type "com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc" is unknown
        at com.sun.jna.Structure.validateField(Structure.java:1109)
        at com.sun.jna.Structure.validateFields(Structure.java:1119)
        at com.sun.jna.Structure.<init>(Structure.java:179)
        at com.sun.jna.Structure.<init>(Structure.java:172)
        at com.sun.jna.Structure.<init>(Structure.java:159)
        at com.sun.jna.Structure.<init>(Structure.java:151)
        at com.dewdropgames.chipmunk2djna.structs.CpSpace.<init>(CpSpace.java:13)
        at com.dewdropgames.chipmunk2djna.structs.CpSpace$ByReference.<init>(CpSpace.java:54)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
        at java.lang.Class.newInstance(Class.java:442)
        at com.sun.jna.Structure.newInstance(Structure.java:1773)
        at com.sun.jna.Structure.newInstance(Structure.java:1759)
        at com.sun.jna.Function.invoke(Function.java:424)
        at com.sun.jna.Function.invoke(Function.java:323)
        at com.sun.jna.Library$Handler.invoke(Library.java:236)
        at com.sun.proxy.$Proxy0.cpSpaceNew(Unknown Source)
        at com.dewdropgames.chipmunk2djna.FirstTry.main(FirstTry.java:31)
Caused by: java.lang.IllegalArgumentException: Invalid Structure field in class com.dewdropgames.chipmunk2djna.structs.CpBody, field name 'position_func' (interface com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc): The type "com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc" is not supported: Native size for type "com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc" is unknown

Initializing cpSpace - Chipmunk v7.0.1 (Debug Enabled)
Compile with -DNDEBUG defined to disable debug mode and runtime assertion checks
        at com.sun.jna.Structure.validateField(Structure.java:1109)
        at com.sun.jna.Structure.validateFields(Structure.java:1119)
        at com.sun.jna.Structure.<init>(Structure.java:179)
        at com.sun.jna.Structure.<init>(Structure.java:172)
        at com.sun.jna.Structure.<init>(Structure.java:159)
        at com.sun.jna.Structure.<init>(Structure.java:151)
        at com.dewdropgames.chipmunk2djna.structs.CpBody.<init>(CpBody.java:15)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
        at java.lang.Class.newInstance(Class.java:442)
        at com.sun.jna.Structure.newInstance(Structure.java:1773)
        at com.sun.jna.Structure.newInstance(Structure.java:1759)
        at com.sun.jna.Structure.size(Structure.java:1030)
        at com.sun.jna.Native.getNativeSize(Native.java:1172)
        at com.sun.jna.Structure.getNativeSize(Structure.java:2072)
        at com.sun.jna.Structure.getNativeSize(Structure.java:2062)
        at com.sun.jna.Structure.validateField(Structure.java:1105)
        ... 19 more
Caused by: java.lang.IllegalArgumentException: The type "com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc" is not supported: Native size for type "com.dewdropgames.chipmunk2djna.callbacks.CpBodyPositionFunc" is unknown
        at com.sun.jna.Native.getNativeSize(Native.java:1180)
        at com.sun.jna.Structure.getNativeSize(Structure.java:2072)
        at com.sun.jna.Structure.getNativeSize(Structure.java:2062)
        at com.sun.jna.Structure.validateField(Structure.java:1105)
        ... 37 more