java鼠标钩子实现

java本身是没有提供直接访问系统的API方法，查了下资料，要实现鼠标钩子有3种方法，
1、使用JNI方法，需要自己写C实现，比较复杂。
2、使用swt extension，直接提供了鼠标钩子的实现，但是用它调用其它windows api，没有成功，放弃了使用它。
3、使用JNA，JNA是建立在JNI 技术之上的，简化了Java访问window api的方法。
考虑到要调用其它window api的原因，选用了JNA，顺便写一个JNA实现鼠标钩子的测试例子：

public class MouseHook extends JFrame {
	private static final long serialVersionUID = 1L;
	public static final int WM_MOUSEMOVE = 512;
	public static final int WM_LBUTTONDOWN = 513;
	public static final int WM_LBUTTONUP = 514;
	public static final int WM_RBUTTONDOWN = 516;
	public static final int WM_RBUTTONUP = 517;
	public static final int WM_MBUTTONDOWN = 519;
	public static final int WM_MBUTTONUP = 520;
	private static HHOOK hhk;
	private static LowLevelMouseProc mouseHook;

	private JLabel labelX;
	private JLabel labelY;
	private JPanel contentPane;

	public static void main(String[] args) {
		final MouseHook frame = new MouseHook();
		frame.setVisible(true);

		final User32 lib = User32.INSTANCE;
		HMODULE hMod = Kernel32.INSTANCE.GetModuleHandle(null);
		mouseHook = new LowLevelMouseProc() {
			public LRESULT callback(int nCode, WPARAM wParam,
					MOUSEHOOKSTRUCT info) {
				if (nCode >= 0) {
					switch (wParam.intValue()) {
					case MouseHook.WM_MOUSEMOVE:
						System.err.println("in callback,  x=" + info.pt.x
								+ " y=" + info.pt.y);
						frame.getLabelX().setText(String.valueOf(info.pt.x));
						frame.getLabelY().setText(String.valueOf(info.pt.y));
					}
				}
				return lib
						.CallNextHookEx(hhk, nCode, wParam, info.getPointer());
			}
		};
		hhk = lib.SetWindowsHookEx(User32.WH_MOUSE_LL, mouseHook, hMod, 0);

		int result;
		MSG msg = new MSG();
		while ((result = lib.GetMessage(msg, null, 0, 0)) != 0) {
			if (result == -1) {
				System.err.println("error in get message");
				break;
			} else {
				System.err.println("got message");
				lib.TranslateMessage(msg);
				lib.DispatchMessage(msg);
			}
		}
		lib.UnhookWindowsHookEx(hhk);
	}

	public MouseHook() {
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setBounds(100, 100, 450, 300);
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		setContentPane(contentPane);
		contentPane.setLayout(null);

		JLabel lblX = new JLabel("X:");
		lblX.setFont(new Font("宋体", Font.PLAIN, 14));
		lblX.setBounds(46, 33, 22, 27);
		contentPane.add(lblX);

		JLabel lblY = new JLabel("Y:");
		lblY.setFont(new Font("宋体", Font.PLAIN, 14));
		lblY.setBounds(144, 39, 17, 15);
		contentPane.add(lblY);

		labelX = new JLabel("");
		labelX.setBounds(65, 39, 54, 15);
		contentPane.add(labelX);

		labelY = new JLabel("");
		labelY.setBounds(160, 39, 54, 15);
		contentPane.add(labelY);
	}

	public JLabel getLabelX() {
		return labelX;
	}

	public void setLabelX(JLabel labelX) {
		this.labelX = labelX;
	}

	public JLabel getLabelY() {
		return labelY;
	}

	public void setLabelY(JLabel labelY) {
		this.labelY = labelY;
	}

	public interface LowLevelMouseProc extends HOOKPROC {
		LRESULT callback(int nCode, WPARAM wParam, MOUSEHOOKSTRUCT lParam);
	}

	public class Point extends Structure {
		public class ByReference extends Point implements Structure.ByReference {
		};
		public com.sun.jna.NativeLong x;
		public com.sun.jna.NativeLong y;
	}

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

		public User32.POINT pt;
		public User32.HWND hwnd;
		public int wHitTestCode;
		public User32.ULONG_PTR dwExtraInfo;
	}
}

运行程序

源码