Java后台获取USB二维码扫描枪内容(Java监听系统键盘操作)

上一篇文章中用JNA实现的键盘监听,在Windows上完美运行,能在后台拿到扫描枪扫描输入的内容,可在Linux下还是没办法,于是在网上各种找,又找到两种办法,还是一样,在Windows上运行都没问题,最后都失败在Linux,最后,我看失败的错误描述,貌似问题都出在了图形界面X11上面还有什么键盘布局上,我的Ubuntu系统,不是标准的那种布局,就运行失败了。想了想,虽然失败了,还是记录一下吧,万一有使用redhat等系统的运行没问题呢?

一、使用jnativehook监听键盘输入

    jnativehook也是个开源项目,项目地址:kwhat/jnativehook,这个项目也是全平台支持的,Windows,Linux、Mac全都支持,但是Linux下貌似是需要装X11,然后键盘布局也得是相关,不然报错了。我运行的报错如下:

Java后台获取USB二维码扫描枪内容(Java监听系统键盘操作)_第1张图片

报错里面的symbols/pc105我也不懂什么东西,网上一查,感觉就是个键盘类型,就像除了我们用的qwer标准键盘外,还有IBM的有F13的键盘,日文输入键盘等,总之就是我装的Ubuntu系统中没有这个文件,导致报错。但是其他系统说不定就没问题。

这个项目使用也挺简单的,从他的仓库下载JAR包,下载下来,用命令运行java -jar jnativehook.jar,就能出现一个用Swing绘制的图形小程序demo,简单演示监听到的鼠标键盘等输入,具体怎么调用的,将jar包放入eclispe,查看包内的src/java/org/jnativehook/example/NativeHookDemo.java文件就可以看到了。项目要引用,也只需要这一个jar包导入就可以,实现方法也很简单,跟Swing程序中鼠标键盘监听一模一样。下面贴上我简单实现的鼠标监听的代码,其他鼠标监听之类的可以自己研究下官方Demo源码,很明了。

import java.util.logging.Level;
import java.util.logging.Logger;

import org.jnativehook.GlobalScreen;
import org.jnativehook.NativeHookException;
import org.jnativehook.dispatcher.DefaultDispatchService;
import org.jnativehook.keyboard.NativeKeyEvent;
import org.jnativehook.keyboard.NativeKeyListener;

public class Test implements NativeKeyListener{
    private static final Logger logger = Logger.getLogger(GlobalScreen.class.getPackage().getName());
    
    public static void main(String[] args) {
        //关闭日志
        logger.setLevel(Level.OFF);
        new Test();
    }
    
    public Test() {
        //添加监听调度员,如果是Swing程序,就用SwingDispatchService,不是就用默认的
        GlobalScreen.setEventDispatcher(new DefaultDispatchService());
        try {
            //注册监听
            GlobalScreen.registerNativeHook();
            //加入键盘监听,
            GlobalScreen.addNativeKeyListener(this);
        } catch (NativeHookException e) {
            e.printStackTrace();
        }
    }

    //实现键盘监听的三个方法,根据自己情况实现
    @Override
    public void nativeKeyTyped(NativeKeyEvent nativeEvent) {
        System.out.println("typed"+nativeEvent.paramString());
    }

    @Override
    public void nativeKeyPressed(NativeKeyEvent nativeEvent) {
        System.out.println("pressed"+nativeEvent.paramString());
    }

    @Override
    public void nativeKeyReleased(NativeKeyEvent nativeEvent) {
        System.out.println("released"+nativeEvent.paramString());
    }
}

二、使用JXGrabKey来监听

       JXGrabKey原本是用来注册热键的,上一篇文章中介绍过,用来实现监听键盘有点怪,但如果没有更好的解决办法时,这也是一种办法,

github项目地址为:https://github.com/friedmag/jxgrabkey  不过这个里面没有相关的jar包和so文件,需要去http://sourceforge.net/projects/jxgrabkey/ 这里面下载,需要引入jar包,还需要加载so文件,还用刀了SWT的相关东西,所以你还得加入SWT的jar包,从eclipse目录下找到\plugins\org.eclipse.swt.win32.win32.x86_64_3.106.0.v20170608-0516.jar,这个包,添加到项目中才可以。

    具体我的思路是将每一个按键当作一个热键,都去实现自己要实现的操作。虽然很麻烦,但确实管用!而且在我的Ubuntu下运行成功!都没报任何错。可以试试,下面贴上我的代码,只简单实现了将0-9的数字捕获,按下回车即输出。

Java后台获取USB二维码扫描枪内容(Java监听系统键盘操作)_第2张图片

import java.awt.event.KeyEvent;
import java.io.File;
import java.util.ArrayList;
import java.util.List;

import javax.swing.JOptionPane;

import jxgrabkey.HotkeyConflictException;
import jxgrabkey.HotkeyListener;
import jxgrabkey.JXGrabKey;

public class JXGrabKeyTest {

    private static final int MY_HOTKEY_INDEX_0 = 0;
    private static final int MY_HOTKEY_INDEX_1 = 1;
    private static final int MY_HOTKEY_INDEX_2 = 2;
    private static final int MY_HOTKEY_INDEX_3 = 3;
    private static final int MY_HOTKEY_INDEX_4 = 4;
    private static final int MY_HOTKEY_INDEX_5 = 5;
    private static final int MY_HOTKEY_INDEX_6 = 6;
    private static final int MY_HOTKEY_INDEX_7 = 7;
    private static final int MY_HOTKEY_INDEX_8 = 8;
    private static final int MY_HOTKEY_INDEX_9 = 9;
    private static final int MY_HOTKEY_INDEX_100 = 100;
    private static boolean hotkeyEventReceived = false;
    
    static List singleInput = new ArrayList();

    private static String caseCode() {
        StringBuffer buffer = new StringBuffer();
        for (Character i : singleInput) {
            buffer.append(i);
        }
        return buffer.toString();
    }
    
    public static void main(String[] args) throws Exception {
        //Load JXGrabKey lib
        System.load(new File("lib/libJXGrabKey.so").getCanonicalPath());
        
        //Enable Debug Output
        JXGrabKey.setDebugOutput(true);
        
        //Register some Hotkey
        try{
            //int key = KeyEvent.VK_K, mask = KeyEvent.CTRL_MASK | KeyEvent.ALT_MASK | KeyEvent.SHIFT_MASK;
            //int key = KeyEvent.VK_F2, mask = KeyEvent.ALT_MASK; //Conflicts on GNOME
            
            JXGrabKey.getInstance().registerAwtHotkey(MY_HOTKEY_INDEX_0, KeyEvent.KEY_LOCATION_UNKNOWN, KeyEvent.VK_0);
            JXGrabKey.getInstance().registerAwtHotkey(MY_HOTKEY_INDEX_1, KeyEvent.KEY_LOCATION_UNKNOWN, KeyEvent.VK_1);
            JXGrabKey.getInstance().registerAwtHotkey(MY_HOTKEY_INDEX_2, KeyEvent.KEY_LOCATION_UNKNOWN, KeyEvent.VK_2);
            JXGrabKey.getInstance().registerAwtHotkey(MY_HOTKEY_INDEX_3, KeyEvent.KEY_LOCATION_UNKNOWN, KeyEvent.VK_3);
            JXGrabKey.getInstance().registerAwtHotkey(MY_HOTKEY_INDEX_4, KeyEvent.KEY_LOCATION_UNKNOWN, KeyEvent.VK_4);
            JXGrabKey.getInstance().registerAwtHotkey(MY_HOTKEY_INDEX_5, KeyEvent.KEY_LOCATION_UNKNOWN, KeyEvent.VK_5);
            JXGrabKey.getInstance().registerAwtHotkey(MY_HOTKEY_INDEX_6, KeyEvent.KEY_LOCATION_UNKNOWN, KeyEvent.VK_6);
            JXGrabKey.getInstance().registerAwtHotkey(MY_HOTKEY_INDEX_7, KeyEvent.KEY_LOCATION_UNKNOWN, KeyEvent.VK_7);
            JXGrabKey.getInstance().registerAwtHotkey(MY_HOTKEY_INDEX_8, KeyEvent.KEY_LOCATION_UNKNOWN, KeyEvent.VK_8);
            JXGrabKey.getInstance().registerAwtHotkey(MY_HOTKEY_INDEX_9, KeyEvent.KEY_LOCATION_UNKNOWN, KeyEvent.VK_9);
            JXGrabKey.getInstance().registerAwtHotkey(MY_HOTKEY_INDEX_100, KeyEvent.KEY_LOCATION_UNKNOWN, KeyEvent.VK_ENTER);
        }catch(HotkeyConflictException e){
            JOptionPane.showMessageDialog(null, e.getMessage(), e.getClass().getName(), JOptionPane.ERROR_MESSAGE);
            
            JXGrabKey.getInstance().cleanUp(); //Automatically unregisters Hotkeys and Listeners
            //Alternatively, just unregister the key causing this or leave it as it is 
            //the key may not be grabbed at all or may not respond when numlock, capslock or scrollock is on
            return;
        }
                
        //Implement HotkeyListener
        HotkeyListener hotkeyListener = new jxgrabkey.HotkeyListener(){
            public void onHotkey(int hotkey_idx) {
                switch(hotkey_idx) {
                    case MY_HOTKEY_INDEX_0:
                        singleInput.add((char) 0);
                    case MY_HOTKEY_INDEX_1:
                        singleInput.add((char) 1);
                    case MY_HOTKEY_INDEX_2:
                        singleInput.add((char) 2);
                    case MY_HOTKEY_INDEX_3:
                        singleInput.add((char) 3);
                    case MY_HOTKEY_INDEX_4:
                        singleInput.add((char) 4);
                    case MY_HOTKEY_INDEX_5:
                        singleInput.add((char) 5);
                    case MY_HOTKEY_INDEX_6:
                        singleInput.add((char) 6);
                    case MY_HOTKEY_INDEX_7:
                        singleInput.add((char) 7);
                    case MY_HOTKEY_INDEX_8:
                        singleInput.add((char) 8);
                    case MY_HOTKEY_INDEX_9:
                        singleInput.add((char) 9);
                    case MY_HOTKEY_INDEX_100:
                        System.out.println(caseCode());
                        singleInput.clear();
                }
                //hotkeyEventReceived = true;
            }
        };
        
        //Add HotkeyListener
        JXGrabKey.getInstance().addHotkeyListener(hotkeyListener);
        
//        //Wait for Hotkey Event
//        while(!hotkeyEventReceived){
//            Thread.sleep(1000);
//        }
//        
//        // Shutdown JXGrabKey
//        JXGrabKey.getInstance().unregisterHotKey(MY_HOTKEY_INDEX); //Optional
//        JXGrabKey.getInstance().removeHotkeyListener(hotkeyListener); //Optional
//        JXGrabKey.getInstance().cleanUp();
    }
}

 

转载于:https://www.cnblogs.com/plumsq/p/10709122.html

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