Question

我使用JNA从Java访问某些dll函数，这个dll Native Function声明如下：

unsigned int ts3client_initClientLib(const struct ClientUIFunctions* functionPointers, const struct ClientUIFunctionsRare* functionRarePointers, int usedLogTypes, const char* logFileFolder, const char* resourcesFolder);

所以，我在库接口中声明它如下：

int ts3client_initClientLib(Structure functionPointers, Structure functionRarePointers, int usedLogTypes, String logFileFolder, String resourcesFolder);

然后我用以下方式调用它：

ts3client_initClientLib(null, null, 1, "log.log", "soundbackends");

但我得到以下例外：

Exception in thread "main" java.lang.Error: Invalid memory access
    at com.sun.jna.Native.invokeInt(Native Method)
    at com.sun.jna.Function.invoke(Function.java:383)
    at com.sun.jna.Function.invoke(Function.java:315)
    at com.sun.jna.Library$Handler.invoke(Library.java:212)
    at com.sun.proxy.$Proxy0.ts3client_initClientLib(Unknown Source)
    at pl.edu.tirex.ts3musicbot.MusicBot.main(MusicBot.java:17)

Answer 1

正确的解决方案：

创建活动界面：

import com.sun.jna;

public interface ServerErrorEvent implements Callback
{
    void invoke(long serverConnectionHandlerID, String errorMessage, int error, String returnCode, String extraMessage);
}

创建客户端UI功能结构：

import com.sun.jna.Structure;

public class EventsStructure extends Structure
{
    public ServerErrorEvent onServerErrorEvent;

    @SuppressWarnings("rawtypes")
    @Override
    protected List<String> getFieldOrder() 
    {
        List<String> fields = new ArrayList<String>();
        for (Field f : this.getClass().getDeclaredFields())
        {
            boolean has = false;
            for (Class<?> c : f.getType().getInterfaces())
            {
                if (c.equals(DefaultEvent.class))
                {
                    has = true;
                }
            }
            if (has)
            {
                fields.add(f.getName());
            }
        }
        return fields;
    }
}

使用以下方法：

EventsStructure eventStructure = new EventsStructure();
eventStructure.onServerErrorEvent = new ServerErrorEvent() //implement server error event
{
    @Override
    public void invoke(long serverConnectionHandlerID, String errorMessage, int error, String returnCode, String extraMessage)
    {
        System.out.println("server error");
    }
};
ts3client_initClientLib(eventStructure, null, 0, "logs", "soundbackends"); //invoke ts3client_initClientLib function from library

JNA：java.lang.Error：无效的内存访问 - TS3库

1 个答案: