基于usb4java实现的java下的usb通信

不羁岁月 提交于 2020-03-08 08:03:21

项目地址:点击打开

使用java开发的好处就是跨平台,基本上java的开发的程序在linux、mac、MS上都可以运行,对应这java的那句经典名言:一次编写,到处运行。这个项目里面有两种包选择,一个是low-level(libus)一个是high-level(javax-usb),相关的优缺点在官方网站上已经说明了,我这里就不翻译了,不过前者好像基于libusb已经好久不更新了,所以还是选择后者。

配置:你需要在你包的根目录下新建一个名为:javax.usb.properties的文件,里面的内容是这样的:

javax.usb.services = org.usb4java.javax.Services

查找usb设备,其实通过usb通信流程大体上都是一致,之前我做过android与arduino通过usb通信,然后java通信走了一遍之后发现是一样的。USB 设备棵树上进行管理所有物理集线器连接一个虚拟的 USB集线器更多集线器可以连接这些集线器任何集线器可以大量连接的 USB设备

通常需要使用之前搜索特定设备,下面的一个例子如何扫描一个特定供应商产品 id 第一个设备设备:

public UsbDevice findDevice(UsbHub hub, short vendorId, short productId)
{
    for (UsbDevice device : (List<UsbDevice>) hub.getAttachedUsbDevices())
    {
        UsbDeviceDescriptor desc = device.getUsbDeviceDescriptor();
        if (desc.idVendor() == vendorId && desc.idProduct() == productId) return device;
        if (device.isUsbHub())
        {
            device = findDevice((UsbHub) device, vendorId, productId);
            if (device != null) return device;
        }
    }
    return null;
}

接口

当你想要与一个接口或者这个接口的端点进行通信时,那么你在使用它之前必须要claim它,并且当你结束时你必须释放它。比如:下面的代码:

UsbConfiguration configuration = device.getActiveUsbConfiguration();
UsbInterface iface = configuration.getUsbInterface((byte) 1);
iface.claim();
try
{
    ... Communicate with the interface or endpoints ...
}
finally        
{
    iface.release();
}

可能出现的一种情况是你想要通信的接口已经被内核驱动使用,在这种情况下你可能需要通过传递一个接口策略到claim方法以此尝试强制claim:

iface.claim(new UsbInterfacePolicy()
{            
    @Override
    public boolean forceClaim(UsbInterface usbInterface)
    {
        return true;
    }
});

需要注意的是,接口策略只是为了实现基础USB的一个提示.接口策略在MS-Windows上将被忽略,因为libusb在windows上不支持分派驱动。

同步 I/O

这个example发送8个字节到端点0x03:

UsbEndpoint endpoint = iface.getUsbEndpoint(0x03);
UsbPipe pipe = endpoint.getUsbPipe();
pipe.open();
try
{
    int sent = pipe.syncSubmit(new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 });
    System.out.println(sent + " bytes sent");
}
finally
{
    pipe.close();
}

这个example是从端点0x83读取8个字节:

UsbEndpoint endpoint = iface.getUsbEndpoint((byte) 0x83);
UsbPipe pipe = endpoint.getUsbPipe();
pipe.open();
try
{
    byte[] data = new byte[8];
    int received = pipe.syncSubmit(data);
    System.out.println(received + " bytes received");
}
finally
{
    pipe.close();
}

异步 I/O

同步I/O操作与异步I/O操作类似,仅仅是使用asyncSubmint方法取代syncSubmit方法。syncSubmit方法将会阻塞直到请求完成,而asyncSubmit不会阻塞并且立即返回,为了接受请求的返回,你必须为Pipe添加一个监听器,像下面这样:

pipe.addUsbPipeListener(new UsbPipeListener()
{            
    @Override
    public void errorEventOccurred(UsbPipeErrorEvent event)
    {
        UsbException error = event.getUsbException();
        ... Handle error ...
    }
    
    @Override
    public void dataEventOccurred(UsbPipeDataEvent event)
    {
        byte[] data = event.getData();
        ... Process received data ...
    }
});

遇到的问题:在Linux上不能打开设备Device,其实是权限的问题导致的,你应该知道在Linux下权限分配是一门很重要的学问,其实该问题在官方网站的FAQ一栏已经提供了解决的办法,地址:点击打开

在Linux环境下,你需要给你想要通信的usb设备写一个许可文件。在此之前,你可以以root用户运行你的程序检查设备是否可以获取,如果有上述操作有作用,那么我推荐配置下udev以便当设备连接上后你的用户拥有对设备写的权限

  SUBSYSTEM=="usb",ATTR{idVendor}=="89ab",ATTR{idProduct}=="4567",MODE="0660",GROUP="wheel"

需要该更改的就是PID、VID、GROUP,关于PID和VID信息以及查看相关的接口、端口信息的查看,linux下可以使用一个叫usbview的软件,软件安装很简单,仅仅一条命令:

sudo apt-get insall usbview

注意启动的时候需要权限,而且还需要以图形界面显示(sudo usbview在我的Linux Mint没有反应的):

sudo gksu usbview

 参考官方写的一段简单的代码:

package nir.desktop.demo;

import java.util.List;

import javax.usb.UsbConfiguration;
import javax.usb.UsbConst;
import javax.usb.UsbControlIrp;
import javax.usb.UsbDevice;
import javax.usb.UsbDeviceDescriptor;
import javax.usb.UsbEndpoint;
import javax.usb.UsbException;
import javax.usb.UsbHostManager;
import javax.usb.UsbHub;
import javax.usb.UsbInterface;
import javax.usb.UsbInterfacePolicy;
import javax.usb.UsbPipe;
import javax.usb.event.UsbPipeDataEvent;
import javax.usb.event.UsbPipeErrorEvent;
import javax.usb.event.UsbPipeListener;

public class UsbConn {
     private static final short VENDOR_ID = 0x2341;
     /** The product ID of the missile launcher. */
     private static final short PRODUCT_ID = 0x43;
//    private static final short VENDOR_ID = 0x10c4;
//    // /** The product ID of the missile launcher. */
//    private static final short PRODUCT_ID = -5536;
    private static UsbPipe pipe81, pipe01;

    /**
     * 依据VID和PID找到设备device
     * 
     * @param hub
     * @return
     */
    @SuppressWarnings("unchecked")
    public static UsbDevice findMissileLauncher(UsbHub hub) {
        UsbDevice launcher = null;

        for (UsbDevice device : (List<UsbDevice>) hub.getAttachedUsbDevices()) {
            if (device.isUsbHub()) {
                launcher = findMissileLauncher((UsbHub) device);
                if (launcher != null)
                    return launcher;
            } else {
                UsbDeviceDescriptor desc = device.getUsbDeviceDescriptor();
                if (desc.idVendor() == VENDOR_ID
                        && desc.idProduct() == PRODUCT_ID) {
                    System.out.println("找到设备:" + device);
                    return device;
                }
            }
        }
        return null;
    }

    public static void sendMessage(UsbDevice device, byte[] message)
            throws UsbException {
        UsbControlIrp irp = device
                .createUsbControlIrp(
                        (byte) (UsbConst.REQUESTTYPE_TYPE_CLASS | UsbConst.REQUESTTYPE_RECIPIENT_INTERFACE),
                        (byte) 0x09, (short) 2, (short) 1);
        irp.setData(message);
        device.syncSubmit(irp);
    }

    /**
     * 注意权限的配置问题,在linux下可能无法打开device,解决办法参考官方的FAQ
     * 
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        UsbDevice device;
        try {
            device = findMissileLauncher(UsbHostManager.getUsbServices()
                    .getRootUsbHub());
            if (device == null) {
                System.out.println("Missile launcher not found.");
                System.exit(1);
                return;
            }
            UsbConfiguration configuration = device.getActiveUsbConfiguration();//获取配置信息
            UsbInterface iface = configuration.getUsbInterface((byte) 1);//接口
            iface.claim(new UsbInterfacePolicy() {

                @Override
                public boolean forceClaim(UsbInterface arg0) {
                    // TODO Auto-generated method stub
                    return true;
                }
            });
            // for (UsbEndpoint endpoints : (List<UsbEndpoint>) iface
            // .getUsbEndpoints()) {
            // System.out.println("--->"+endpoints.getUsbEndpointDescriptor());
            // }
            UsbEndpoint endpoint81 = iface.getUsbEndpoint((byte) 0x83);//接受数据地址
            UsbEndpoint endpoint01 = iface.getUsbEndpoint((byte)0x04);//发送数据地址
            pipe81 = endpoint81.getUsbPipe();
            pipe81.open();
            pipe01 = endpoint01.getUsbPipe();
            pipe01.open();
            byte[] dataSend = { (byte) 0x00 };//需要发送的数据
            pipe01.asyncSubmit(dataSend);
            pipe81.addUsbPipeListener(new UsbPipeListener() {
                
                @Override
                public void errorEventOccurred(UsbPipeErrorEvent arg0) {
                    // TODO Auto-generated method stub
                    System.out.println(arg0);
                }
                
                @Override
                public void dataEventOccurred(UsbPipeDataEvent arg0) {
                    // TODO Auto-generated method stub
                    System.out.println(new String(arg0.getData()));
                }
            });
//             pipe81.close();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            //
        }
    }
}

其中的一些接口、端口都是依据usbview写的,数据是发成功了(RX灯亮了),但是因为我使用的是arduino,里面的代码不知道怎么写,如果有这方便的高手还请帮我一下,谢谢。翻墙看了下有的人用的是同步传输出现的问题,相关的解决办法,这里我就完全粘贴、复制了:Here is an abbreviated example. Note that I have removed from this, allchecks, error handling, and such.It is just the logic of creating two pipes for two endpoints. One IN andone OUT. Then using them to do a write and a read.It assumes that endpoint 2 is an OUT and endpoint 4 is an IN.Note also that the name of an IN endpoint is OR'd with 0x80:

import javax.usb.*;

public class Example {

public static void main(String[] args) throws Exception {
UsbDevice usbDevice = ...getUsbDevice by matching vID, pID, knowing
the path... or whatever works for you...
usbDevice.getUsbConfigurations();
UsbConfiguration config = usbDevice.getActiveUsbConfiguration();
UsbInterface xface = config.getUsbInterface((byte)0);
xface.claim();

UsbEndpoint endPt2 = xface.getUsbEndpoint((byte)2); //OUT
endpoint
UsbEndpoint endPt4 = xface.getUsbEndpoint((byte)(4 | 0x80) ); //IN
endpoint

UsbPipe pipe2 = endPt2.getUsbPipe();
pipe2.open();
UsbPipe pipe4 = endPt4.getUsbPipe();
pipe4.open();

//Use the pipes:
byte[] bytesToSend = new byte[] {1,2,3}; //Going to send out these 3
bytes
UsbIrp irpSend = pipe2.createUsbIrp();
irpSend.setData(bytesToSend);
pipe2.asyncSubmit(irpSend); //Send out some bytes
irpSend.waitUntilComplete(1000); //Wait up to 1 second

byte[] bytesToRead = new byte[3]; //Going to read 3 bytes into here
UsbIrp irpRead = pipe2.createUsbIrp();
irpRead.setData(bytesToRead);
pipe4.asyncSubmit(irpRead); //Read some bytes
irpRead.waitUntilComplete(1000); //Wait up to 1 second
}
}
View Code

下面是我监听数据返回点完整代码:

 UsbConn.java:

package DemoMath;

import java.util.List;

import javax.usb.UsbConfiguration;
import javax.usb.UsbConst;
import javax.usb.UsbControlIrp;
import javax.usb.UsbDevice;
import javax.usb.UsbDeviceDescriptor;
import javax.usb.UsbEndpoint;
import javax.usb.UsbException;
import javax.usb.UsbHostManager;
import javax.usb.UsbHub;
import javax.usb.UsbInterface;
import javax.usb.UsbInterfacePolicy;
import javax.usb.UsbPipe;
import javax.usb.util.UsbUtil;

public class UsbConn {
    private static final short VENDOR_ID = 0x04b4;
    private static final short PRODUCT_ID = 0x1004;
    private static final byte INTERFACE_AD= 0x00;
    private static final byte ENDPOINT_OUT= 0x02;
    private static final byte ENDPOINT_IN= (byte) 0x86;
    private static final byte[] COMMAND = {0x01,0x00};

    @SuppressWarnings("unchecked")
    public static UsbDevice findMissileLauncher(UsbHub hub) {
        UsbDevice launcher = null;

        for (UsbDevice device : (List<UsbDevice>) hub.getAttachedUsbDevices()) {
            if (device.isUsbHub()) {
                launcher = findMissileLauncher((UsbHub) device);
                if (launcher != null)
                    return launcher;
            } else {
                UsbDeviceDescriptor desc = device.getUsbDeviceDescriptor();
                if (desc.idVendor() == VENDOR_ID
                        && desc.idProduct() == PRODUCT_ID) {
                    System.out.println("发现设备" + device);
                    return device;
                }
            }
        }
        return null;
    }
    //command for controlTransfer
    public static void sendMessage(UsbDevice device, byte[] message)
            throws UsbException {
        UsbControlIrp irp = device
                .createUsbControlIrp(
                        (byte) (UsbConst.REQUESTTYPE_TYPE_CLASS | UsbConst.REQUESTTYPE_RECIPIENT_INTERFACE),
                        (byte) 0x09, (short) 2, (short) 1);
        irp.setData(message);
        device.syncSubmit(irp);
    }
    /**
     * Class to listen in a dedicated Thread for data coming events.
     * This really could be used for any HID device.
     */
    public static class HidMouseRunnable implements Runnable
    {
        /* This pipe must be the HID interface's interrupt-type in-direction endpoint's pipe. */
        public HidMouseRunnable(UsbPipe pipe) { usbPipe = pipe; }
        public void run()
        {
            byte[] buffer = new byte[UsbUtil.unsignedInt(usbPipe.getUsbEndpoint().getUsbEndpointDescriptor().wMaxPacketSize())];
            @SuppressWarnings("unused")
            int length = 0;

            while (running) {
                try {
                    length = usbPipe.syncSubmit(buffer);
                } catch ( UsbException uE ) {
                    if (running) {
                        System.out.println("Unable to submit data buffer to HID mouse : " + uE.getMessage());
                        break;
                    }
                }
                if (running) {
//                    System.out.print("Got " + length + " bytes of data from HID mouse :");
//                    for (int i=0; i<length; i++)
//                        System.out.print(" 0x" + UsbUtil.toHexString(buffer[i]));
                    try {
                        String result = DataFix.getHexString(buffer); 
                        System.out.println(result);
                    } catch (Exception e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }
        }
        /**
         * Stop/abort listening for data events.
         */
        public void stop()
        {
            running = false;
            usbPipe.abortAllSubmissions();
        }
        public boolean running = true;
        public UsbPipe usbPipe = null;
    }
    /**
     * get the  correct Interface for USB
     * @param device
     * @return
     * @throws UsbException
     */
    public static UsbInterface readInit() throws UsbException{
        UsbDevice device = findMissileLauncher(UsbHostManager.getUsbServices()
                .getRootUsbHub());
        if (device == null) {
            System.out.println("Missile launcher not found.");
            System.exit(1);
        }
        UsbConfiguration configuration = device.getActiveUsbConfiguration();
        UsbInterface iface = configuration.getUsbInterface(INTERFACE_AD);//Interface Alternate Number
        //if you using the MS os,may be you need judge,because MS do not need follow code,by tong
        iface.claim(new UsbInterfacePolicy() {
            @Override
            public boolean forceClaim(UsbInterface arg0) {
                // TODO Auto-generated method stub
                return true;
            }
        });
        return iface;
    }
    /**
     * 异步bulk传输,by tong
     * @param usbInterface
     * @param data
     */
    public static void syncSend(UsbInterface usbInterface,byte[] data) {
        UsbEndpoint endpoint = usbInterface.getUsbEndpoint(ENDPOINT_OUT);
        UsbPipe outPipe = endpoint.getUsbPipe();
        try {
            outPipe.open();
            outPipe.syncSubmit(data);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            try {
                outPipe.close();
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
    public static HidMouseRunnable listenData(UsbInterface usbInterface) {
        UsbEndpoint endpoint = usbInterface.getUsbEndpoint(ENDPOINT_IN);
        UsbPipe inPipe = endpoint.getUsbPipe();
        HidMouseRunnable hmR = null;
        try {
            inPipe.open();
            hmR = new HidMouseRunnable(inPipe);
            Thread t = new Thread(hmR);
            t.start();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return hmR;
    }
    /**
     * 主程序入口
     * 
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
            UsbInterface iface;
            try {
                iface = readInit();
                listenData(iface);
                syncSend(iface, COMMAND);
            } catch (UsbException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
    }
}
View Code

 

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