1、在不同android版本的模拟器上进行串口测试，并修复代码

SerialPort/build.gradle

@@ -8,8 +8,6 @@ android {
     defaultConfig {
         minSdk 16
         targetSdk 30
-        versionCode 1
-        versionName "1.0"
 
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
         consumerProguardFiles "consumer-rules.pro"

SerialPort/src/main/AndroidManifest.xml

@@ -2,4 +2,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="top.lyoun.serialport">
 
+    <!--serial need read and write privilege-->
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
+    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
+
 </manifest>

SerialPort/src/main/java/top/lyoun/serialport/RequestStoragePrivileges.java

@@ -0,0 +1,23 @@
+package top.lyoun.serialport;
+
+import android.Manifest;
+import android.app.Activity;
+import android.app.Application;
+
+import androidx.core.app.ActivityCompat;
+
+/**
+ * @author LyounJAP
+ * @title: RequestStoragePrivileges
+ * @projectName AndroidSerialHelper
+ * @description: dynamic acquire storage read/write privileges
+ * @date 2022-01-17 16:32
+ */
+public class RequestStoragePrivileges {
+
+    public static void requestStoragePrivileges(Activity activity){
+        ActivityCompat.requestPermissions(activity,
+                new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.READ_EXTERNAL_STORAGE},
+                1);
+    }
+}

SerialPort/src/main/java/top/lyoun/serialport/SerialPort.java

@@ -43,7 +43,8 @@ public final class SerialPort {
 
     private static final String TAG = "SerialPort";
 
-    public static final String DEFAULT_SU_PATH = "/system/bin/su";
+    //android6及其以上开发版（且android6以下的也能用）：/system/bin/sh
+    public static final String DEFAULT_SU_PATH = "/system/bin/sh"; ///system/bin/su
 
     private static String sSuPath = DEFAULT_SU_PATH;
     private File device; //串口设备文件
@@ -235,9 +236,13 @@ public void handleMessage(Message msg) {
     private void stopSendThread() {
         mSendingHandler = null;
         if (null != mSendingHandlerThread) {
-            mSendingHandlerThread.interrupt();
-            mSendingHandlerThread.quit();
-            mSendingHandlerThread = null;
+            try {
+                mSendingHandlerThread.interrupt();
+                mSendingHandlerThread.quit();
+                mSendingHandlerThread = null;
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
         }
     }
 
@@ -271,7 +276,7 @@ private void stopReceivedThread() {
      * @param device 文件
      * @return 权限修改是否成功
      */
-    private boolean chmod777(File device) {
+    public static boolean chmod777(File device) {
         if (null == device || !device.exists()) {
             return false;
         }
@@ -296,7 +301,7 @@ private boolean openSafe(File device, int baudrate, int dataBits, int parity,
             Log.e(TAG, "openSafe: 文件不存在或文件不能为空！");
             return false;
         }
-        Log.i(TAG, String.format("SerialPort: %s: %d,%d,%d,%d,%d,%d", device.getPath(), baudrate, dataBits, parity, stopBits, flags));
+        Log.i(TAG, String.format("SerialPort: %s: %d,%d,%d,%d,%d", device.getPath(), baudrate, dataBits, parity, stopBits, flags));
         if (!device.canRead() || !device.canWrite()) {
             boolean chmod777 = chmod777(device);
             if (!chmod777) {

SerialPort/src/main/java/top/lyoun/serialport/SerialPortFinder.java

@@ -16,6 +16,7 @@
 
 package top.lyoun.serialport;
 
+import android.app.Activity;
 import android.util.Log;
 import java.io.File;
 import java.io.FileReader;
@@ -48,6 +49,8 @@ public Vector<File> getDevices() {
 
                 File[] files = dev.listFiles();
 
+                Log.i(TAG, "driver: " + files);
+
                 if (files != null) {
                     int i;
                     for (i = 0; i < files.length; i++) {
@@ -70,7 +73,10 @@ public String getName() {
 
     private Vector<Driver> mDrivers = null;
 
+    Activity activity;
+
     Vector<Driver> getDrivers() throws IOException {
+
         if (mDrivers == null) {
             mDrivers = new Vector<Driver>();
             LineNumberReader r = new LineNumberReader(new FileReader("/proc/tty/drivers"));
@@ -90,7 +96,9 @@ Vector<Driver> getDrivers() throws IOException {
         return mDrivers;
     }
 
-    public String[] getAllDevices() {
+    public String[] getAllDevices(Activity activity) {
+        this.activity = activity;
+
         Vector<String> devices = new Vector<String>();
         // Parse each driver
         Iterator<Driver> itdriv;
@@ -99,6 +107,7 @@ public String[] getAllDevices() {
             while (itdriv.hasNext()) {
                 Driver driver = itdriv.next();
                 Iterator<File> itdev = driver.getDevices().iterator();
+
                 while (itdev.hasNext()) {
                     String device = itdev.next().getName();
                     String value = String.format("%s (%s)", device, driver.getName());
@@ -130,4 +139,5 @@ public String[] getAllDevicesPath() {
         }
         return devices.toArray(new String[devices.size()]);
     }
+
 }

SerialPort/src/main/java/top/lyoun/serialport/SerialReadThread.java

@@ -1,5 +1,7 @@
 package top.lyoun.serialport;
 
+import android.util.Log;
+
 import java.io.IOException;
 import java.io.InputStream;
 
@@ -14,6 +16,7 @@ public abstract class SerialReadThread extends Thread{
 
     private InputStream mInputStream;
     private byte[] mReceivedBuffer;
+    private boolean reading;
 
     public SerialReadThread(InputStream inputStream) {
         mInputStream = inputStream;
@@ -23,7 +26,8 @@ public SerialReadThread(InputStream inputStream) {
     @Override
     public void run() {
         super.run();
-        while (!isInterrupted()) {
+        reading = true;
+        while (reading) {
             try {
                 if (null == mInputStream) {
                     return;
@@ -34,7 +38,9 @@ public void run() {
                 }
                 byte[] receivedBytes = new byte[size];
                 System.arraycopy(mReceivedBuffer, 0, receivedBytes, 0, size);
-                onDataReceived(receivedBytes);
+                if (reading) {
+                    onDataReceived(receivedBytes);
+                }
             } catch (IOException e) {
                 e.printStackTrace();
             }
@@ -47,15 +53,20 @@ public void run() {
      * 释放
      */
     public void release() {
-        interrupt();
+        try {
+            reading = false;
+            interrupt();
 
-        if (null != mInputStream) {
-            try {
-                mInputStream.close();
-            } catch (IOException e) {
-                e.printStackTrace();
+            if (null != mInputStream) {
+                try {
+                    mInputStream.close();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+                mInputStream = null;
             }
-            mInputStream = null;
+        } catch (Exception e) {
+            e.printStackTrace();
         }
     }
 }

app/src/main/AndroidManifest.xml

@@ -2,7 +2,12 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="top.lyoun.androidserialhelper">
 
+    <!--serial need read and write privilege-->
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
+    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
+
     <application
+        android:requestLegacyExternalStorage="true"
         android:name=".Application"
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"

app/src/main/java/top/lyoun/androidserialhelper/Application.java

@@ -20,8 +20,8 @@ public class Application extends android.app.Application {
     public SerialPort getSerial1(){
         if(mSerial1 == null){
             mSerial1 = SerialPort.newBuilder(
-                    "/dev/ttymxc1",
-                    115200)
+                    "/dev/ttyS1",
+                    9600)
                     .build();
         }
 

app/src/main/java/top/lyoun/androidserialhelper/MainActivity.java

@@ -15,6 +15,7 @@
 
 import top.lyoun.androidserialhelper.databinding.ActivityMainBinding;
 import top.lyoun.serialport.Hello;
+import top.lyoun.serialport.RequestStoragePrivileges;
 import top.lyoun.serialport.SerialPort;
 import top.lyoun.serialport.Welcome;
 import top.lyoun.serialport.listener.OnSerialDataListener;
@@ -54,8 +55,10 @@ protected void onCreate(Bundle savedInstanceState) {
         mSerial1 = mApplication.getSerial1();
 
         //读取设备列表
-        Log.i(TAG, "allDevices: " + Arrays.toString(mApplication.mSerialPortFinder.getAllDevices()));
+        Log.i(TAG, "allDevices: " + Arrays.toString(mApplication.mSerialPortFinder.getAllDevices(this)));
+        Log.i(TAG, "\n=============================\n");
         Log.i(TAG, "allDevicesPath: " + Arrays.toString(mApplication.mSerialPortFinder.getAllDevicesPath()));
+
     }
 
     @Override

build.gradle

@@ -5,7 +5,7 @@ buildscript {
         mavenCentral()
     }
     dependencies {
-        classpath "com.android.tools.build:gradle:7.0.0"
+        classpath 'com.android.tools.build:gradle:7.0.4'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files