寻 JNI高手帮忙解决一个问题，万分感谢！

[blackkettle]

JNI 达人，我改写了一个全局监听的 java调用 dll的代码，可是一运行就 JVM crash.

请达人帮我看看是什么原因，非常感谢！


运行环境：

OS: Windows XP Build 2600 Service Pack 3

CPU:total 2 (2 cores per cpu, 1 threads per core) family 6 model 23 stepping 10, cmov, cx8, fxsr, mmx, sse, sse2, sse3, ssse3, sse4.1

Memory: 4k page, physical 2091204k(875764k free), swap 4029236k(2644760k free)

vm_info: Java HotSpot(TM) Client VM (20.4-b02) for windows-x86 JRE (1.6.0_29-b11), built on Oct 3 2011 01:01:08 by "java_re" with MS VC++ 7.1 (VS2003)


Example.java

package jni;

public class Example  implements KeyboardEventListener {

    static GlobalEventListener gl;

	public static void main(String[] args) throws Exception  
	{
		Example inst = new Example();
		gl = new GlobalEventListener();
	  	gl.addKeyboardEventListener(inst);
	}
			
    public void GlobalKeyPressed( KeyboardEvent event )
	{
    	
		System.out.println( "Key Pressed: " + event.getVirtualKeyCode() );
	}

	public void GlobalKeyReleased( KeyboardEvent event )
	{
		System.out.println( "Key Released: " + event.getVirtualKeyCode() );
	}
	
}

GlobalEventListener.java

package jni;

public class GlobalEventListener
{
	PoolHook pt;
	public GlobalEventListener()
	{
		pt = new PoolHook(this);
		pt.start();
			
	}
 
	protected javax.swing.event.EventListenerList listenerList = new javax.swing.event.EventListenerList();
 	
	public void addKeyboardEventListener(KeyboardEventListener listener)
	{
		listenerList.add( KeyboardEventListener.class, listener );
	}
 
	public void removeKeyboardEventListener(KeyboardEventListener listener)
	{
		listenerList.remove( KeyboardEventListener.class, listener );
	}
	
	
	void keyPressed(KeyboardEvent event)
	{
		Object[] listeners = listenerList.getListenerList();
		for ( int i = 0; i < listeners.length; i += 2 )
		{
			if ( listeners[ i ] == KeyboardEventListener.class )
			{
				( (KeyboardEventListener)listeners[i + 1] ).GlobalKeyPressed( event );
			}
		}
	}
 
	void keyReleased(KeyboardEvent event)
	{
		Object[] listeners = listenerList.getListenerList();
		for ( int i = 0; i < listeners.length; i += 2 )
		{
			if ( listeners[ i ] == KeyboardEventListener.class )
			{
				( (KeyboardEventListener)listeners[i + 1] ).GlobalKeyReleased( event );
			}
		}
	}
	
	
}
 

KeyboardEventListener.java

package jni;

import java.util.*;
 
public interface KeyboardEventListener extends EventListener
{
	public void GlobalKeyPressed( KeyboardEvent event );
	public void GlobalKeyReleased( KeyboardEvent event );
}


class KeyboardEvent extends EventObject
{
	private static final long serialVersionUID = 2341653211621224652L;
	boolean ts, ap, ek;
	int vk;
 
	public KeyboardEvent( Object source, boolean ts, int vk, boolean ap, boolean ek )
	{
		super(source);
		this.ts = ts;
		this.vk = vk;
		this.ap = ap;
		this.ek = ek;
	}
 
	public boolean getTransitionState()
	{
		return ts;
	}
 
	public long getVirtualKeyCode()
	{
		return vk;
	}
 
	public boolean isAltPressed()
	{
		return ap;
	}
 
	public boolean isExtendedKey()
	{
		return ek;
	}
 
	public boolean equals( KeyboardEvent event )
	{
		if( event.getVirtualKeyCode() == vk )
		{
			if( event.isExtendedKey() == ek )
			{
				if( event.isAltPressed() == ap )
				{
					return true;
				}
			}
		}
		return false;
	}
}

SysHook.java

package jni;

class PoolHook extends Thread
{
	SysHook hook;
	GlobalEventListener g_gl;
	PoolHook(GlobalEventListener gl)
	{
		g_gl = gl;
	}
	
	
	public void run() 
	{
		hook = new SysHook();
		hook.registerHook(g_gl);
	}
	
}

class SysHook
{
	
	static 
	{
		System.loadLibrary("SysHook");
	}
	
	void processKey(  boolean ts  ,int vk, GlobalEventListener gl) 
	{
		KeyboardEvent event = new KeyboardEvent( this, ts, vk,false, false );
		if(ts == true)
			gl.keyPressed(event);
		else if(ts == false)
			gl.keyReleased(event);
	}
	
	void mouseMoved(int cord_x, int cord_y, GlobalEventListener gl) 
	{
		//MouseEvent event = new MouseEvent( this, cord_x, cord_y);
		//gl.mouseMoved(event);
	}

	native void registerHook(GlobalEventListener gl);
	native void unRegisterHook();

	
}

jni_SysHook.h

/* DO NOT EDIT THIS FILE - it is machine generated */
#include "jni.h"
/* Header for class jni_SysHook */

#ifndef _Included_jni_SysHook
#define _Included_jni_SysHook
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     jni_SysHook
 * Method:    registerHook
 * Signature: (Ljni/GlobalEventListener;)V
 */
JNIEXPORT void JNICALL Java_jni_SysHook_registerHook
  (JNIEnv *, jobject, jobject);

/*
 * Class:     jni_SysHook
 * Method:    unRegisterHook
 * Signature: ()V
 */
JNIEXPORT void JNICALL Java_jni_SysHook_unRegisterHook
  (JNIEnv *, jobject);

#ifdef __cplusplus
}
#endif
#endif

SysHook.cpp

#include <windows.h>
#include <WinUser.h>
#include "SysHook.h"
#include "jni_SysHook.h"
#include "jni.h"

#ifndef WINVER
#define WINVER 0x0500
#endif

#ifndef _WIN32_WINNT
#define _WIN32_WINNT 0x0500
#endif

#if (_WIN32_WINNT >= 0x0400)
#define WH_KEYBOARD_LL 13
#define WH_MOUSE_LL 14
#endif // (_WIN32_WINNT >= 0x0400)

typedef   struct   tagKBDLLHOOKSTRUCT   { 
         DWORD   vkCode;             //   virtual   key   code 
         DWORD   scanCode;         //   scan   code 
         DWORD   flags;               //   flags 
         DWORD   time;                 //   time   stamp   for   this   message 
         DWORD   dwExtraInfo;   //   extra   info   from   the   driver   or   keybd_event 
 }KBDLLHOOKSTRUCT,   FAR   *LPKBDLLHOOKSTRUCT,   *PKBDLLHOOKSTRUCT;

HINSTANCE hInst = NULL;

JavaVM * jvm = NULL;
jobject hookObj_kb = NULL;
jobject hookObj_ms = NULL;
jobject g_kl = NULL;

jmethodID processKeyID_kb = NULL;
jmethodID processKeyID_ms = NULL;
DWORD hookThreadId = 0;

LONG g_mouseLocX = -1;    // x-location of mouse position
LONG g_mouseLocY = -1;    // y-location of mouse position

extern "C"
BOOL APIENTRY DllMain(HINSTANCE _hInst, DWORD reason, LPVOID reserved)
{
	switch (reason)
	{
	case DLL_PROCESS_ATTACH:
		printf("C++: DllMain - DLL_PROCESS_ATTACH.\n");
		hInst = _hInst;
		break;
	default:
		break;
	}
	
	return TRUE;
}

LRESULT CALLBACK MouseTracker(int nCode, WPARAM wParam, LPARAM lParam)
{
	JNIEnv * env;
	KBDLLHOOKSTRUCT * p = (KBDLLHOOKSTRUCT *)lParam;
	
	if (jvm->AttachCurrentThread((void **)&env, NULL) >= 0)
	{
		
		if (nCode==HC_ACTION)
		{
			MOUSEHOOKSTRUCT* pStruct = (MOUSEHOOKSTRUCT*)lParam;
			if (pStruct->pt.x != g_mouseLocX || pStruct->pt.y != g_mouseLocY)
			{
				env->CallVoidMethod(hookObj_ms, processKeyID_ms, (jint)pStruct->pt.x,(jint)pStruct->pt.y, g_kl);
				g_mouseLocX = pStruct->pt.x;
				g_mouseLocY = pStruct->pt.y;
			}
			
		}
		
	}
	else
	{
		printf("C++: LowLevelKeyboardProc - Error on the attach current thread.\n");
	}
	
	return CallNextHookEx(NULL, nCode, wParam, lParam);
}

LRESULT CALLBACK LowLevelKeyboardProc(int nCode, WPARAM wParam, LPARAM lParam)
{
	JNIEnv * env;
	KBDLLHOOKSTRUCT * p = (KBDLLHOOKSTRUCT *)lParam;
	
	if(jvm->AttachCurrentThread((void **)&env, NULL) >= 0)
	{
		switch (wParam)
		{
		case WM_KEYDOWN:
		case WM_SYSKEYDOWN:
			env->CallVoidMethod(hookObj_kb, processKeyID_kb, (jboolean)TRUE, p->vkCode,g_kl);
			break;
		case WM_KEYUP:
		case WM_SYSKEYUP:
			env->CallVoidMethod(hookObj_kb, processKeyID_kb, (jboolean)FALSE, p->vkCode,g_kl);
			break;
		default:
			break;
		}
	}
	else
	{
		printf("C++: LowLevelKeyboardProc - Error on the attach current thread.\n");
	}
	
	return CallNextHookEx(NULL, nCode, wParam, lParam);
}

void MsgLoop()
{
	MSG message;
	while (GetMessage(&message, NULL, 0, 0))
	{
		TranslateMessage(&message);
		DispatchMessage(&message);
	}
}

JNIEXPORT void JNICALL Java_jni_SysHook_registerHook(JNIEnv * env, jobject obj,jobject kl)
{
	HHOOK hookHandle_ms = SetWindowsHookEx(WH_MOUSE_LL, MouseTracker, hInst, 0);
	HHOOK hookHandle_kb = SetWindowsHookEx(WH_KEYBOARD_LL, LowLevelKeyboardProc, hInst, 0);
	
	g_kl = kl;
	
	if (hookHandle_ms == NULL)
	{
		printf("C++: Java_SysHook_registerKeyHook - Hook failed!\n");
		return;
	}
	else
	{
		printf("C++: Java_SysHook_registerKeyHook - Hook successful\n");
	}
	
	if (hookHandle_kb == NULL)
	{
		printf("C++: Java_SysHook_registerKeyHook - Hook failed!\n");
		return;
	}
	else
	{
		printf("C++: Java_SysHook_registerKeyHook - Hook successful\n");
	}
	
	hookObj_kb = env->NewGlobalRef(obj);
	jclass cls_kb = env->GetObjectClass(hookObj_kb);
	processKeyID_kb = env->GetMethodID(cls_kb, "processKey", "(ZILGlobalEventListener;)V");
	
	hookObj_ms = env->NewGlobalRef(obj);
	jclass cls_ms = env->GetObjectClass(hookObj_ms);
	processKeyID_ms = env->GetMethodID(cls_ms, "mouseMoved", "(IILGlobalEventListener;)V");
	
	env->GetJavaVM(&jvm);
	hookThreadId = GetCurrentThreadId();
	
	MsgLoop();
	
	if (!UnhookWindowsHookEx(hookHandle_kb))
	{
		printf("C++: Java_SysHook_registerKeyHook - Unhook failed\n");
	}
	else
	{
		printf("C++: Java_SysHook_registerKeyHook - Unhook successful\n");
	}
	
	if (!UnhookWindowsHookEx(hookHandle_ms))
	{
		printf("C++: Java_SysHook_registerKeyHook - Unhook failed\n");
	}
	else
	{
		printf("C++: Java_SysHook_registerKeyHook - Unhook successful\n");
	}
}

JNIEXPORT void JNICALL Java_jni_SysHook_unRegisterHook(JNIEnv *env, jobject object)
{
	if (hookThreadId == 0)
		return;
	
	printf("C++: Java_SysHook_unRegisterKeyHook - call PostThreadMessage.\n");
	PostThreadMessage(hookThreadId, WM_QUIT, 0, 0L);
}

[BadPattern]

问题我想应该找到了：
这两行:
processKeyID_kb = env->GetMethodID(cls_kb, "processKey", "(ZILGlobalEventListener;)V");

processKeyID_ms = env->GetMethodID(cls_ms, "mouseMoved", "(IILGlobalEventListener;)V");

得到的processKeyID_kb和processKeyID_ms应该为NULL,你可以打印看看，之后调用CallVoidMethod肯定会空指针.
(ZILGlobalEventListener;)V应该是全限定性名称:(ZILjni/GlobalEventListener;)V

(IILGlobalEventListener;)V同样的应该改为(IILjni/GlobalEventListener;)V

你试试看

[blackkettle]

dr8737010，

你太厉害了！！！搞定了！

我问了好多搞 java的同学，他们几乎都没有搞过 jni,都解答不了这个问题。

万分感谢！！！

[BadPattern]

[Quote=引用 6 楼 的回复:]

dr8737010，

你太厉害了！！！搞定了！

我问了好多搞 java的同学，他们几乎都没有搞过 jni,都解答不了这个问题。

万分感谢！！！
[/Quote]
呵呵，那就结帖给分吧

[blackkettle]

[Quote=引用 7 楼 的回复:]

引用 6 楼 的回复:

dr8737010，

你太厉害了！！！搞定了！

我问了好多搞 java的同学，他们几乎都没有搞过 jni,都解答不了这个问题。

万分感谢！！！

呵呵，那就结帖给分吧
[/Quote]

那是必须的。

[BadPattern]

这。。。代码太多，而且没有调试环境很难定位问题啊，JVM挂掉很可能因为dll库写的有问题，你多加Log跟踪一下看看哪里代码没执行到

[blackkettle]

[Quote=引用 1 楼 的回复:]

这。。。代码太多，而且没有调试环境很难定位问题啊，JVM挂掉很可能因为dll库写的有问题，你多加Log跟踪一下看看哪里代码没执行到
[/Quote]

dr8737010,

您帮我看看吧。我是在这里找到源码的。
http://dengpeng.sensorapp.net/?p=495

源码是在 默认包下的，可以执行没有问题。

我想改写成指定包下。可是就出了问题。

万分感谢！

[BadPattern]

改成指定包没关系，因为我看到你的native方法相应的也变成了:
Java_jni_SysHook_registerHook
和
Java_jni_SysHook_unRegisterHook

按照jni的规则是可以映射上的,还是要你在这两个方法中加点Log打印或者加个断点看看执行如何

[blackkettle]

那个博客上好像有人留言说也遇到的同样的情况。

---（摘）



java代码是用的默认包，我可以正常编译和执行（包括C和JAVA代码都可以正常编译和调用）。
但是如果Java代码放在包中实现，就可以正常加载dll，但是截获键盘和鼠标时就会报错。
希望你帮忙看看是什么问题

#
# A fatal error has been detected by the Java Runtime Environment:
#
# EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x6d9acbb5, pid=4004, tid=3276
#
# JRE version: 6.0_19-b04
# Java VM: Java HotSpot(TM) Client VM (16.2-b04 mixed mode, sharing windows-x86 )
# Problematic frame:
# V [jvm.dll+0xfcbb5]
#
# An error report file with more information is saved as:
# F:\work35\KeyHookWithPackage\hs_err_pid4004.log
#
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
#
C++: DllMain – DLL_PROCESS_ATTACH.
C++: Java_SysHook_registerKeyHook – Hook successful