我已经整理了用于在 Windows 中安装键盘挂钩的 JNA 代码（使用 JNA 示例）。代码编译完毕，一切顺利，我安装了挂钩（我成功获得了挂钩的句柄），我也可以成功卸载挂钩。但是，当我按键盘上的任何键时，回调永远不会被调用。这是我的代码（大部分是从 JNA 示例中获取的类型定义，对于我的部分，请直接转到“main”）
import com.sun.jna.IntegerType;
import com.sun.jna.Pointer;
import com.sun.jna.PointerType;
import com.sun.jna.Structure;
import com.sun.jna.FromNativeContext;
import com.sun.jna.ptr.IntByReference;
import com.sun.jna.ptr.PointerByReference;
import com.sun.jna.win32.StdCallLibrary;
import com.sun.jna.win32.StdCallLibrary.StdCallCallback;
import com.sun.jna.Native;
import com.sun.jna.Platform;
import com.sun.jna.Library;
import com.sun.jna.win32.W32APITypeMapper;
import com.sun.jna.win32.W32APIFunctionMapper;
import java.util.Map;
import java.util.HashMap;
public class HelloWorld {
static Map UNICODE_OPTIONS = new HashMap() {
{
put("type-mapper", W32APITypeMapper.UNICODE);
put("function-mapper", W32APIFunctionMapper.UNICODE);
}
};
public static class LONG_PTR extends IntegerType {
public LONG_PTR() { this(0); }
public LONG_PTR(long value) { super(Pointer.SIZE, value); }
}
public static class UINT_PTR extends IntegerType {
public UINT_PTR() { super(Pointer.SIZE); }
public UINT_PTR(long value) { super(Pointer.SIZE, value); }
public Pointer toPointer() { return Pointer.createConstant(longValue()); }
}
public static class ULONG_PTR extends IntegerType {
public ULONG_PTR() { this(0); }
public ULONG_PTR(long value) { super(Pointer.SIZE, value); }
}
public static class LRESULT extends LONG_PTR {
public LRESULT() { this(0); }
public LRESULT(long value) { super(value); }
}
public static class WPARAM extends UINT_PTR {
public WPARAM() { this(0); }
public WPARAM(long value) { super(value); }
}
public static class LPARAM extends LONG_PTR {
public LPARAM() { this(0); }
public LPARAM(long value) { super(value); }
}
public static class KBDLLHOOKSTRUCT extends Structure {
public int vkCode;
public int scanCode;
public int flags;
public int time;
public ULONG_PTR dwExtraInfo;
}
static HANDLE INVALID_HANDLE_VALUE = new HANDLE() {
{ super.setPointer(Pointer.createConstant(-1)); }
public void setPointer(Pointer p) {
throw new UnsupportedOperationException("Immutable reference");
}
};
public static class HANDLE extends PointerType {
public Object fromNative(Object nativeValue, FromNativeContext context) {
Object o = super.fromNative(nativeValue, context);
if (INVALID_HANDLE_VALUE.equals(o))
return INVALID_HANDLE_VALUE;
return o;
}
}
public static class HHOOK extends HANDLE { }
public static class HINSTANCE extends HANDLE { }
public static class HMODULE extends HINSTANCE { }
public interface User32 extends StdCallLibrary {
User32 INSTANCE = (User32)Native.loadLibrary("user32", User32.class, UNICODE_OPTIONS);
static final int WH_KEYBOARD_LL = 13;
public static interface HOOKPROC extends StdCallCallback {
LRESULT callback(int nCode, WPARAM wParam, KBDLLHOOKSTRUCT lParam);
}
HHOOK SetWindowsHookEx(int idHook, HOOKPROC lpfn, HMODULE hMod, int dwThreadId);
LRESULT CallNextHookEx(HHOOK idHook, int nCode, WPARAM wParam, LPARAM lParam);
LRESULT CallNextHookEx(HHOOK idHook, int nCode, WPARAM wParam, Pointer lParam);
boolean UnhookWindowsHookEx(HHOOK idHook);
}
public interface Kernel32 extends StdCallLibrary {
Kernel32 INSTANCE = (Kernel32)Native.loadLibrary("kernel32", Kernel32.class, UNICODE_OPTIONS);
HMODULE GetModuleHandle(String name);
}
public static HHOOK hHook;
public static User32.HOOKPROC lpfn;
public static volatile boolean quit = false;
public static void main(String[] args) throws Exception {
HMODULE hMod = Kernel32.INSTANCE.GetModuleHandle(null);
System.out.println(hMod);
lpfn = new User32.HOOKPROC() {
public LRESULT callback(int nCode, WPARAM wParam, KBDLLHOOKSTRUCT lParam) {
System.out.println("here");
quit = true;
return User32.INSTANCE.CallNextHookEx(hHook, nCode, wParam, lParam.getPointer());
}
};
hHook = User32.INSTANCE.SetWindowsHookEx(User32.WH_KEYBOARD_LL, lpfn, hMod, 0);
System.out.println(hHook);
if(hHook != null)
System.out.println("Keyboard hooked, type anything to quit");
while(!quit) {
Thread.sleep(100);
}
if(User32.INSTANCE.UnhookWindowsHookEx(hHook))
System.out.println("Unhooked");
}
}
过去我曾多次使用 C++ 和 C# 完成键盘/鼠标挂钩。这是我第一次尝试使用 Java，我只是不知道我是否正确导入和映射了库。有什么想法吗？
谢谢你。
看来您需要调用
GetMessagePeekMessage我刚刚使用了示例类：
import com.sun.jna.examples.win32.*;
public class Callback {
public static User32.HHOOK hHook;
public static User32.LowLevelKeyboardProc lpfn;
public static volatile boolean quit = false;
public static void main(String[] args) throws Exception {
W32API.HMODULE hMod = Kernel32.INSTANCE.GetModuleHandle(null);
lpfn = new User32.LowLevelKeyboardProc() {
public W32API.LRESULT callback(int nCode, W32API.WPARAM wParam,
User32.KBDLLHOOKSTRUCT lParam) {
System.out.println("here");
quit = true;
return User32.INSTANCE.CallNextHookEx(hHook, nCode, wParam, lParam
.getPointer());
}
};
hHook = User32.INSTANCE.SetWindowsHookEx(User32.WH_KEYBOARD_LL, lpfn, hMod,
0);
if (hHook == null)
return;
User32.MSG msg = new User32.MSG();
while (!quit) {
User32.INSTANCE.PeekMessage(msg, null, 0, 0, 0);
Thread.sleep(100);
}
if (User32.INSTANCE.UnhookWindowsHookEx(hHook))
System.out.println("Unhooked");
}
}
一个极简主义的例子：
import com.sun.jna.platform.win32.Kernel32;
import com.sun.jna.platform.win32.User32;
import com.sun.jna.platform.win32.WinDef.HINSTANCE;
import com.sun.jna.platform.win32.WinDef.LPARAM;
import com.sun.jna.platform.win32.WinDef.LRESULT;
import com.sun.jna.platform.win32.WinDef.WPARAM;
import com.sun.jna.platform.win32.WinUser.HOOKPROC;
public class MainTestKeyHook {
public static void main(String[] args) throws Exception {
HOOKPROC hookProc = new HOOKPROC_bg();
HINSTANCE hInst = Kernel32.INSTANCE.GetModuleHandle(null);
User32.HHOOK hHook = User32.INSTANCE.SetWindowsHookEx(User32.WH_KEYBOARD_LL, hookProc, hInst, 0);
if (hHook == null)
return;
User32.MSG msg = new User32.MSG();
System.err.println("Please press any key ....");
while (true) {
User32.INSTANCE.GetMessage(msg, null, 0, 0);
}
}
}
class HOOKPROC_bg implements HOOKPROC {
public HOOKPROC_bg() {
}
public LRESULT callback(int nCode, WPARAM wParam, LPARAM lParam) {
System.err.println("callback bbbnhkilhjkibh nCode: " + nCode);
return new LRESULT(0);
}
}
我使用了上面发布的最小示例，并添加了 jna jar 和 jna 平台 jar。编辑器没有显示任何失败，所以我想我正确地完成了依赖关系。但如果我编译我仍然会收到错误。有人知道为什么以及如何解决它吗？ :)
无法在项目 MainTestKeyHook 上执行目标 org.codehaus.mojo:exec-maven-plugin:3.1.0:exec (default-cli)：命令执行失败。：进程退出并出现错误：1（退出值：1） - > [帮助1]
要查看错误的完整堆栈跟踪，请使用 -e 开关重新运行 Maven。 使用 -X 开关重新运行 Maven 以启用完整的调试日志记录。
有关错误和可能的解决方案的更多信息，请阅读以下文章： [帮助 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException