Android Studio : 使用 jni 实现串口通讯

添加 SerialPort 类

在网上找到 SerialPort 的 java 类，添加到项目中。

package com.xd.serialport;

import android.util.Log;

import java.io.File;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class SerialPort {
	private static final String TAG = "SerialPort";  
	  
	/* 
	 * 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("/system/bin/su");  
	            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);  
	}  
	  
	// Getters and setters  
	public InputStream getInputStream() {  
	    return mFileInputStream;  
	}  
	  
	public OutputStream getOutputStream() {  
	    return mFileOutputStream;  
	}  
	  
	// JNI  
	private native static FileDescriptor open(String path, int baudrate, int