MacOS High Sierra下Java应用原生钩子监听及光标位置实现方案咨询

Absolutely, you can pull off all the required features on macOS High Sierra—including that missing cursor position functionality JNativeHook doesn’t cover. Let’s walk through the best approach, especially since you’re open to Objective-C (even if you’re new to it):

Since you need Java to call native code via JNI, the setup will mirror your Windows C# DLL workflow:

• Define native methods in your Java class
• Write the feature implementations in Objective-C
• Compile the Objective-C code into a macOS dynamic library (.dylib) for Java to load and call

This approach lets you leverage macOS’s native APIs directly, while maintaining seamless integration with your Java app.

1. Cursor Position Retrieval (Your Key Missing Feature) #

macOS’s CGEvent framework provides a dead-simple way to get the cursor’s global position. Here’s a minimal Objective-C implementation for JNI:

#import <Cocoa/Cocoa.h>

JNIEXPORT jobject JNICALL Java_YourJavaClass_getCursorPosition(JNIEnv *env, jobject obj) {
    // Get global cursor coordinates
    CGPoint cursorPos = CGEventGetLocation(NULL);
    
    // Create and return a Java Point object (adjust the class path if using a custom point class)
    jclass pointClass = (*env)->FindClass(env, "java/awt/Point");
    jmethodID constructor = (*env)->GetMethodID(env, pointClass, "<init>", "(II)V");
    jobject pointObj = (*env)->NewObject(env, pointClass, constructor, (int)cursorPos.x, (int)cursorPos.y);
    
    return pointObj;
}

No hooks needed here—CGEventGetLocation(NULL) returns the cursor’s position in the global coordinate system instantly.

2. Mouse & Keyboard Native Hooks #

Use CGEventTap (macOS’s equivalent of Windows hooks) to intercept system-wide mouse and keyboard events. Here’s a basic framework:

#import <Cocoa/Cocoa.h>

CGEventRef eventTapCallback(CGEventTapProxy proxy, CGEventType type, CGEventRef event, void *refcon) {
    // Handle different event types
    switch(type) {
        case kCGEventMouseMoved:
            // Process mouse movement
            break;
        case kCGEventKeyDown:
            // Process key presses
            CGKeyCode keyCode = (CGKeyCode)CGEventGetIntegerValueField(event, kCGKeyboardEventKeycode);
            NSLog(@"Pressed key code: %d", keyCode);
            break;
        // Add more event types as needed
    }
    return event;
}

// Initialize the event tap
JNIEXPORT void JNICALL Java_YourJavaClass_setupEventHooks(JNIEnv *env, jobject obj) {
    CGEventMask eventMask = CGEventMaskBit(kCGEventMouseMoved) | CGEventMaskBit(kCGEventKeyDown);
    CFMachPortRef eventTap = CGEventTapCreate(
        kCGSessionEventTap,
        kCGHeadInsertEventTap,
        0,
        eventMask,
        eventTapCallback,
        NULL
    );

    if (!eventTap) {
        NSLog(@"Failed to create event tap");
        return;
    }

    CFRunLoopSourceRef runLoopSource = CFMachPortCreateRunLoopSource(kCFAllocatorDefault, eventTap, 0);
    CFRunLoopAddSource(CFRunLoopGetCurrent(), runLoopSource, kCFRunLoopCommonModes);
    CGEventTapEnable(eventTap, true);
}

Note: For High Sierra (10.13), you’ll only need to add an NSAppleEventsUsageDescription to your app’s Info.plist (if packaging as a macOS app) or grant accessibility permissions via System Preferences if running via command line.

3. Text Retrieval & Replacement #

Clipboard Operations #

Use NSPasteboard for clipboard text handling:

// Get clipboard text
JNIEXPORT jstring JNICALL Java_YourJavaClass_getClipboardText(JNIEnv *env, jobject obj) {
    NSPasteboard *pasteboard = [NSPasteboard generalPasteboard];
    NSString *clipboardText = [pasteboard stringForType:NSPasteboardTypeString];
    return (*env)->NewStringUTF(env, [clipboardText UTF8String]);
}

// Set clipboard text
JNIEXPORT void JNICALL Java_YourJavaClass_setClipboardText(JNIEnv *env, jobject obj, jstring text) {
    const char *utfText = (*env)->GetStringUTFChars(env, text, NULL);
    NSString *macText = [NSString stringWithUTF8String:utfText];
    
    NSPasteboard *pasteboard = [NSPasteboard generalPasteboard];
    [pasteboard clearContents];
    [pasteboard setString:macText forType:NSPasteboardTypeString];
    
    (*env)->ReleaseStringUTFChars(env, text, utfText);
}

Focused Control Text (Advanced) #

To get text from the currently focused UI element, use the AXUIElement accessibility API (requires accessibility permissions):

#import <ApplicationServices/ApplicationServices.h>

JNIEXPORT jstring JNICALL Java_YourJavaClass_getFocusedText(JNIEnv *env, jobject obj) {
    AXUIElementRef systemWide = AXUIElementCreateSystemWide();
    AXUIElementRef focusedElement = NULL;
    AXUIElementCopyAttributeValue(systemWide, kAXFocusedUIElementAttribute, (CFTypeRef *)&focusedElement);
    
    NSString *focusedText = nil;
    if (focusedElement) {
        AXUIElementCopyAttributeValue(focusedElement, kAXValueAttribute, (CFTypeRef *)&focusedText);
        CFRelease(focusedElement);
    }
    CFRelease(systemWide);
    
    return (*env)->NewStringUTF(env, [focusedText UTF8String]);
}

4. Software Information Retrieval #

Use NSWorkspace to get details about running apps:

// Get frontmost app name
JNIEXPORT jstring JNICALL Java_YourJavaClass_getFrontmostAppName(JNIEnv *env, jobject obj) {
    NSRunningApplication *frontApp = [NSWorkspace sharedWorkspace].frontmostApplication;
    return (*env)->NewStringUTF(env, [frontApp.localizedName UTF8String]);
}

// Get frontmost app bundle ID
JNIEXPORT jstring JNICALL Java_YourJavaClass_getFrontmostAppBundleID(JNIEnv *env, jobject obj) {
    NSRunningApplication *frontApp = [NSWorkspace sharedWorkspace].frontmostApplication;
    return (*env)->NewStringUTF(env, [frontApp.bundleIdentifier UTF8String]);
}

1. Define Native Methods in Java:

public class MacNativeBridge {
    static {
        System.loadLibrary("MacNativeUtils"); // Load the compiled .dylib
    }
    
    public native java.awt.Point getCursorPosition();
    public native void setupEventHooks();
    public native String getClipboardText();
    public native void setClipboardText(String text);
    public native String getFrontmostAppName();
}

2. Generate JNI Header:
   Compile your Java class, then run:

javac -h . MacNativeBridge.java

This will generate a .h file with the required JNI method signatures.
3. Compile Objective-C to .dylib:
Use clang to compile your implementation file (replace $JAVA_HOME with your JDK path):

clang -framework Cocoa -framework ApplicationServices \
-I"$JAVA_HOME/include" -I"$JAVA_HOME/include/darwin" \
-shared -o libMacNativeUtils.dylib MacNativeImpl.m

• Start with basic Objective-C syntax (objects, message sending, Cocoa fundamentals like NSString and NSObject).
• Use Xcode’s auto-completion and Option+click to view official API docs—it’s your best friend.
• Test each feature in a standalone Objective-C app first, then integrate with JNI. This makes debugging way easier.

• Native API Access: Directly using macOS’s frameworks ensures maximum performance and reliability, with full control over every feature (including the missing cursor position).
• Objective-C Fit: As macOS’s native language, it has extensive community support and documentation for system-level tasks.
• Standard JNI Integration: JNI is Java’s official way to call native code, so your implementation will be maintainable and compatible with future Java versions.

内容的提问来源于stack exchange，提问作者hugo411