最进接串口扫码器，参考 github上开源的串口通讯库/cepr/android-serialport-api实现扫码器通讯。
1.集成
Android Studio使用 cmake编译，将SerialPort.c/SerialPort.h两个文件拷贝到 cpp 文件夹下，SerialPort.java拷贝到 android.serialport包下，记得包名要和SerialPort.h中的方法名中的包名一直。了解NDK开发的你懂得。
CMakeLists.txt
# Sets the minimum version of CMake required to build your native library.# This ensures that a certain set of CMake features is available to# your build.cmake_minimum_required(VERSION 3.4.1)# Specifies a library name, specifies whether the library is STATIC or# SHARED, and provides relative paths to the source code. You can# define multiple libraries by adding multiple add.library() commands,# and CMake builds them for you. When you build your app, Gradle# automatically packages shared libraries with your APK.add_library( # Specifies the name of the library.serial_port# Sets the library as a shared library.SHARED# Provides a relative path to your source file(s).src/main/cpp/SerialPort.c)find_library( # Sets the name of the path variable.log-lib# Specifies the name of the NDK library that# you want CMake to locate.log)# Specifies libraries CMake should link to your target library. You# can link multiple libraries, such as libraries you define in this# build script, prebuilt third-party libraries, or system libraries.target_link_libraries( # Specifies the target library.serial_port# Links the target library to the log library# included in the NDK.${log-lib})
public class SerialPort {private static final String TAG = "SerialPort";private static final String DEFAULT_SU_PATH = "/system/bin/su";private static String sSuPath = DEFAULT_SU_PATH;static {System.loadLibrary("serial_port");}/** Do not remove or rename the field mFd: it is used by native method close();*/private FileDescriptor mFd;private FileInputStream mFileInputStream;private FileOutputStream mFileOutputStream;public SerialPort(File device, int baudrate, int flags) throws SecurityException, IOException {/* Check access permission */if (!device.canRead() || !device.canWrite()) {try {/* Missing read/write permission, trying to chmod the file */Process su;su = Runtime.getRuntime().exec(sSuPath);String cmd = "chmod 666 " + device.getAbsolutePath() + "\n" + "exit\n";su.getOutputStream().write(cmd.getBytes());if ((su.waitFor() != 0) || !device.canRead() || !device.canWrite()) {throw new SecurityException();}} catch (Exception e) {e.printStackTrace();throw new SecurityException();}}mFd = open(device.getAbsolutePath(), baudrate, flags);if (mFd == null) {Log.e(TAG, "native open returns null");throw new IOException();}mFileInputStream = new FileInputStream(mFd);mFileOutputStream = new FileOutputStream(mFd);}public SerialPort(String devicePath, int baudrate, int flags)throws SecurityException, IOException {this(new File(devicePath), baudrate, flags);}public SerialPort(File device, int baudrate) throws SecurityException, IOException {this(device, baudrate, 0);}public SerialPort(String devicePath, int baudrate) throws SecurityException, IOException {this(new File(devicePath), baudrate, 0);}/*** Set the su binary path, the default su binary path is {@link #DEFAULT_SU_PATH}** @param suPath su binary path*/public static void setSuPath(String suPath) {if (suPath == null) {return;}sSuPath = suPath;}// JNIprivate native static FileDescriptor open(String path, int baudrate, int flags);// Getters and setterspublic InputStream getInputStream() {return mFileInputStream;}public OutputStream getOutputStream() {return mFileOutputStream;}public native void close();}
2.使用
public SerialPort getSerialPort()throws SecurityException, IOException, InvalidParameterException {if (mSerialPort == null) {//串口：/dev/ttyS4，波特率：115200mSerialPort = new SerialPort(new File("/dev/ttyS4"), 115200);}return mSerialPort;}public void closeSerialPort() {if (mSerialPort != null) {mSerialPort.close();mSerialPort = null;}}private void openSerialPort() {try {mSerialPort =getSerialPort();mInputStream = mSerialPort.getInputStream();mReadThread = new ReadThread();mReadThread.start();} catch (SecurityException e) {e.printStackTrace();ToastCompat.makeText(this, R.string.error_security, Toast.LENGTH_SHORT).show();} catch (IOException e) {e.printStackTrace();ToastCompat.makeText(this, R.string.error_unknown, Toast.LENGTH_SHORT).show();} catch (InvalidParameterException e) {e.printStackTrace();ToastCompat.makeText(this, R.string.error_configuration, Toast.LENGTH_SHORT).show();}}private class ReadThread extends Thread {public ReadThread() {}@Overridepublic void run() {super.run();while (!isInterrupted()) {int size;try {byte[] buffer = new byte[64];if (mInputStream == null) return;size = mInputStream.read(buffer);if (size > 0) {String goodsCode = new String(buffer, 0, size);EventBus.getDefault().post(new GoodsMsgEvent(goodsCode));}} catch (IOException e) {e.printStackTrace();return;}}}}
