java - 从 C 获取结构体(通过引用)

Question

假设我有下一个 C 代码片段，并且我想使用 JNA 从 Java 调用它。

typedef struct {
            int                     bit_a;
            int                     bit_b;
} * bit_handle;

bit_handler handle_open(const char *name, int prop);

出于这样的目的，我编写了下一个 Java 代码片段:

Java代码:

 public interface BitLibrary extends Library {
        BitLibrary INSTANCE = (BitLibrary) Native.loadLibrary("bitlibrary", BitLibrary.class);
        Pointer handler_open(char* name, int prop);
    }

它工作得很好，但我想通过引用检索 BitHandle 对象(请参阅下面的实现)，而不是指针，因为前面的 C 代码中的 bit_handle 是一个指针。我怎么能这么做呢？我尝试过类似 this example 的东西但我得到一个 ClassCastException ，它说 java.lang.reflect.Field 无法转换为 java.lang.Comparable ，我有点无能为力，因为从逻辑角度来看应该可行，但事实并非如此。我错过了什么吗？

BitHandle 实现:

    public static class BitHandle extends Structure {
        public int bit_a;
        public int bit_b;

        public BitHandle(Pointer peer){
            super(peer);
        }

        @Override
        @SuppressWarnings({ "rawtypes", "unchecked" })
        protected List<?> getFieldOrder() {
            List fieldList = new ArrayList(super.getFieldList());
            fieldList.addAll(Arrays.asList("bit_a", "bit_b"));
            return fieldList;
        }

    }

Answer 1

已找到解决方案，感谢@user2864740的建议。关键是忽略 getFieldOrder() javadoc 并按如下方式实现它:

public class BitTest {

    public interface BitLibrary extends Library {
        BitLibrary INSTANCE = (BitLibrary) Native.loadLibrary("bit", BitLibrary.class);

        public static class BitHandle extends Structure {
            public int bit_a;
            public int bit_b;
            public static class ByReference extends BitHandle implements Structure.ByReference {}


            @Override
            protected List getFieldOrder() {
                List<String> fieldList = new ArrayList<>();
                fieldList.addAll(Arrays.asList("bit_a", "bit_b"));
                return (List) fieldList;
            }

        }


        BitHandle.ByReference bit_open(String drivername, int lun);

    }

    public static void main(String[] args) {
        BitLibrary.BitHandle.ByReference pointer = BitLibrary.INSTANCE.Bit_open("CIBM_LINUX", 0);
   }

}