USB打印机开发记录

2019-07-18 本文已影响0人 _非_阳_

最近公司的餐厅点餐app又提了新需求,增加对usb打印机的支持。

USB开发,涉及到主从模式

主机模式
Android设备充当主主设备，并为总线供电。
例如数字相机，键盘，鼠标和游戏控制器。USB设备与Android应用进行数据交互。
附件模式(从属)
外部硬件充当USB主设备，并为总线供电。例如手机和电脑连接

主从模式图

做usb通信，首先要先弄清楚哪边是HOST那边是SLAVE。
比如你的android手机做host，要获得slave，用UsbDevice表示slave
要是你的android手机做slave，要获得host，用UsbAccessory表示host

我们的项目是主模式开发,也就是说USB打印机连接到我们的点餐设备上,点餐设备充当USB主设备,并为总线供电。

首先你可以在manifest.xml清单文件中,声明usb权限是否为必须。
如果不声明，默认为false。

如果required=true,则在安装app的同时,如果android设备不支持usb功能,则app是无法安装的。

同时，做声明的好处是，如果你的app受众人群在国外，那么googleplay会帮你过滤掉没有usb功能的设备，也就是说没有usb功能的设备时搜索不到或者无法下载你的app的!

 <uses-feature
        android:name="android.hardware.usb.host"
        android:required="true" />

声明插入或拔出usb设备时,打开指定的activity.

 <activity
            android:name="com.mjt.print.PrinterConnectDialog"
            android:configChanges="keyboardHidden|orientation|screenSize"
            android:label="@string/app_name"
            android:theme="@android:style/Theme.Light" >

            <intent-filter>
                <!--host模式开发时,在设备插入/拔出时启动该activity的action-->
                <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
                <action android:name="android.hardware.usb.action.USB_DEVICE_DETACHED" />

                <!--accessory模式开发时,在设备插入/拔出时启动该activity的action-->

                <!--<action android:name="android.hardware.usb.action.USB_ACCESSORY_ATTACHED" />-->
                <!--<action android:name="android.hardware.usb.action.USB_ACCESSORY_DETTACHED" />-->
            </intent-filter>

            <!--过滤usb设备,在device_file.xml文件中声明的设备,-->
            <meta-data
                android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
                android:resource="@xml/device_filter" />
           

  </activity>

声明要过滤的usb设备的相关信息

vender-id为生产厂家号 product-id为产品号

其中vendor-id和product-id为插入USB设备的生产厂家号和产品号，在插入（attached）上面列出的设备之一时，就会弹出选择打开应用程序的对话框。

<resources>
    <!-- Accept all device VID/PID combinations -->
    <usb-device vendor-id="22339" product-id="1155" />
</resources>

usb开发的相关api在android.hardware.usb包下

image.png

类	说明
UsbManager	获得 USB 管理器，与连接的 USB 设备通信。
UsbDevice	host模式下,USB 设备的抽象，每个UsbDevice 都代表一个 USB 设备。
UsbAccessory	(从属模式下,也就是你的android设备相当于一个附件挂在usb设备上)此时的UsbAccessory代表的就是android设备所挂在的那个设备
UsbInterface	表示一个UsbDevice的一个接口。UsbDevice可以具有一个或多个在接口用来通信。
UsbEndpoint	表示一个UsbInterface一个端点，它是接口的通信通道。一个接口可以具有一个或多个端点，与设备进行双向通信通常有一个端点用于输入和一个端点用于输出。
UsbDeviceConnection	表示与设备的连接，用来收发数据，传输控制信息。
UsbRequest	通过UsbDeviceConnection与设备通信的异步请求，只用来异步通信
UsbConstants	USB常量定义,与Linux内核的linux / usb / ch9.h中的定义相对应

UsbPort

package com.mjt.factory.print.engine;

import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.hardware.usb.UsbConstants;
import android.hardware.usb.UsbDevice;
import android.hardware.usb.UsbDeviceConnection;
import android.hardware.usb.UsbEndpoint;
import android.hardware.usb.UsbInterface;
import android.hardware.usb.UsbManager;
import android.util.Log;

import com.gprinter.io.PortManager;
import com.gprinter.utils.Utils;
import com.mjt.common.base.CommonLib;

import java.io.IOException;
import java.util.Vector;

import static com.mjt.common.constants.Constants.ACTION_USB_PERMISSION;

/**
 * Copyright:mjt_pad_android
 * Author: liyang <br>
 * Date:2019-05-28 14:07<br>
 * Desc: <br>
 */
public class UsbPort extends PortManager {
    private static final String TAG = UsbPort.class.getSimpleName();


    private UsbDevice usbDevice;

    private UsbManager usbManager;

    private UsbDeviceConnection connection;

    private UsbInterface interf;

    private UsbEndpoint epIn, epOut;

    public static final int USB_REQUEST_CODE = 0;

    public UsbPort(UsbDevice device) {
        usbDevice = device;
        usbManager = (UsbManager) CommonLib.getContext().getSystemService(Context.USB_SERVICE);
    }

    public boolean openPort() {
        if (this.usbDevice != null) {
            if (!this.usbManager.hasPermission(this.usbDevice)) {
                PendingIntent intent = PendingIntent.getBroadcast(CommonLib.getContext(), USB_REQUEST_CODE, new Intent(ACTION_USB_PERMISSION), 0);
                usbManager.requestPermission(usbDevice, intent);
                return false;
            } else {
                openUsbPort();
                return  epOut != null;
            }
        }
        return false;
    }

    private void openUsbPort() {
        int          count        = usbDevice.getInterfaceCount();
        UsbInterface usbInterface = null;

        if (count > 0) {
            usbInterface = usbDevice.getInterface(0);
        }

        if (usbInterface != null) {
            interf = usbInterface;
            connection = null;
            connection = usbManager.openDevice(usbDevice);
        }
        if (connection != null && connection.claimInterface(interf, true)) {
            for (int i = 0; i < interf.getEndpointCount(); ++i) {
                UsbEndpoint ep = interf.getEndpoint(i);
                if (ep.getType() == UsbConstants.USB_ENDPOINT_XFER_BULK) {
                    if (ep.getDirection() == UsbConstants.USB_DIR_OUT) {
                        this.epOut = ep;
                    } else {
                        this.epIn = ep;
                    }
                }
            }
        }

    }

    public void writeDataImmediately(Vector<Byte> data) throws IOException {
        this.writeDataImmediately(data, 0, data.size());
    }


    public void writeDataImmediately(Vector<Byte> data, int offset, int len) throws IOException {
        int          result   = 0;
        Vector<Byte> sendData = new Vector<>();

        for (int i = 0; i < data.size(); ++i) {
            if (sendData.size() >= 1024) {
                Log.e(TAG, "i = " + i + "\tsendData size -> " + sendData.size() + "\tdata size -> " + data.size());
                result += this.connection.bulkTransfer(this.epOut, Utils.convertVectorByteTobytes(sendData), sendData.size(), 1000);
                sendData.clear();
                Log.e(TAG, "sendData.clear() size -> " + sendData.size());
            }

            sendData.add(data.get(i));
        }

        if (sendData.size() > 0) {
            Log.e(TAG, "sendData size -> " + sendData.size());
            result += this.connection.bulkTransfer(this.epOut, Utils.convertVectorByteTobytes(sendData), sendData.size(), 1000);
        }

        if (result == data.size()) {
            Log.d(TAG, "send success");
        }else {
            throw new IOException("send failed");
        }
    }

    public int readData(byte[] bytes) throws IOException {
        return this.connection != null&&epIn!=null ? this.connection.bulkTransfer(this.epIn, bytes, bytes.length, 200) : 0;
    }

    public boolean closePort() {
        if (this.interf != null && this.connection != null) {
            this.connection.releaseInterface(this.interf);
            this.connection.close();
            this.connection = null;
            return true;
        } else {
            return false;
        }
    }

    public UsbDevice getUsbDevice() {
        return this.usbDevice;
    }

    public void setUsbDevice(UsbDevice usbDevice) {
        this.usbDevice = usbDevice;
    }
}

在MainActivity中注册Usb广播

   private final BroadcastReceiver usbDeviceReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            Log.d("action", action);
            UsbDevice mUsbDevice = intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
            if (ACTION_USB_PERMISSION.equals(action)) {
                synchronized (this) {
                    if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false) && mUsbDevice != null) {
                        Log.d("receiver", action + ",device:" + mUsbDevice.getDeviceName() + "被授予了权限!");
                    } else {
                        UIUtils.showToast(context, "USB设备请求被拒绝");
                    }
                }
            } else if (UsbManager.ACTION_USB_DEVICE_DETACHED.equals(action)) {
                if (mUsbDevice != null) {
                    UIUtils.showToast(context, "有设备拔出");
                    EventBus.getDefault().post(new UsbAttachedChangedEvent(mUsbDevice, false));
                }
            } else if (UsbManager.ACTION_USB_DEVICE_ATTACHED.equals(action)) {
                if (mUsbDevice != null) {
                    UIUtils.showToast(context, "有设备插入");
                    EventBus.getDefault().post(new UsbAttachedChangedEvent(mUsbDevice, true));
                }
            }
        }
    };

DeviceConnManager类的openPort方法

  /**
     * 打开端口
     *
     * @return
     */
    public void openPort(boolean needNotify) {
        this.needNotify = needNotify;
        isOpenPort = false;
        sendStateBroadcast(CONN_STATE_CONNECTING);
        switch (connMethod) {
            case BLUETOOTH:
                System.out.println("id -> " + id);
                mPort = new BluetoothPort(macAddress);
                isOpenPort = mPort.openPort();

                break;
            case USB:
                mPort = new UsbPort(mUsbDevice);
                isOpenPort = mPort.openPort();

                break;
            case WIFI:
                mPort = new EthernetPort(ip, port);
                isOpenPort = mPort.openPort();
                break;
            case SERIAL_PORT:
                mPort = new SerialPort(serialPortPath, baudrate, 0);
                isOpenPort = mPort.openPort();
                break;
            default:
                break;
        }
        //端口打开成功后，检查连接打印机所使用的打印机指令ESC、TSC
        Log.e(TAG, "openPort :" + isOpenPort + ",thread is " + Thread.currentThread().getName());
        if (!isOpenPort) {
            if (getConnMethod() == CONN_METHOD.USB && mUsbDevice != null) {
                mUsbDevice = null;
            }
            mPort.closePort();
            sendStateBroadcast(CONN_STATE_FAILED);
        } else {
            sendStateBroadcast(CONN_STATE_CONNECTED);
        }
    }

PrinterManager类中的addUsbPrinter方法和connectUsb方法

  public void addUsbPrinter(String id, String name) {
        DeviceConnFactoryManager usbManager = getManager(id);
        UsbManager               manager    = (UsbManager) CommonLib.getContext().getSystemService(Context.USB_SERVICE);
        UsbDevice                usbDevice  = null;
        for (UsbDevice usb : manager.getDeviceList().values()) {
            String pidVid = String.format("%s%s", usb.getProductId(), usb.getVendorId());
            if (usb.getInterface(0).getInterfaceClass() == UsbConstants.USB_CLASS_PRINTER && pidVid.equals(id)) {
                usbDevice = usb;
            }
        }
        if (usbManager == null) {
            if (usbDevice != null) {
                new DeviceConnFactoryManager.Build().setId(id)
                                                    .setConnMethod(DeviceConnFactoryManager.CONN_METHOD.USB)
                                                    .setName(name)
                                                    .setUsbDevice(usbDevice)
                                                    .build();
            }

        } else {
            //由于usb设备每次查吧usbdevice的deviceId都会变,所以需要重新设备UsbDevice
            if (usbDevice != null && usbManager.usbDevice() == null) {
                usbManager.setUsbDevice(usbDevice);
            }
        }
    }


   public void connectUsb(String pidVid, String name, boolean needNotify) {
        DeviceConnFactoryManager deviceManager = getManager(pidVid);
        UsbManager               manager       = (UsbManager) CommonLib.getContext().getSystemService(Context.USB_SERVICE);
        UsbDevice                usbDevice     = null;
        for (UsbDevice usb : manager.getDeviceList().values()) {
            String pv = String.format("%s%s", usb.getProductId(), usb.getVendorId());
            if (usb.getInterface(0).getInterfaceClass() == UsbConstants.USB_CLASS_PRINTER && pidVid.equals(pv)) {
                usbDevice = usb;
            }
        }
        if (deviceManager == null) {
            if (usbDevice != null) {
                new DeviceConnFactoryManager.Build().setId(pidVid)
                                                    .setConnMethod(DeviceConnFactoryManager.CONN_METHOD.USB)
                                                    .setUsbDevice(usbDevice)
                                                    .setName(name)
                                                    .build();
            } else {
                Log.e(TAG, "connectUsb: usbDevice is null");
            }

        } else {
            if (usbDevice != null) {
                deviceManager.setUsbDevice(usbDevice);
            } else {
                Log.e(TAG, "connectUsb: usbDevice is null");
            }

        }
        if (getManager(pidVid)!=null){
            getManager(pidVid).openPort(needNotify);
        }else {
            UIUtils.showToast("请确保已插入该USB打印机!");
            Log.e(TAG, String.format("connectUsb: getManager(%s)",pidVid));
        }

    }

USB打印机开发记录

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