Merge pull request #1 from evision-ai/feat/set-read-delay-when-initia…

…lizing-serial-port-manager

allow user to set read delay when initializing serial port manager

SerialPortLibrary/src/main/java/com/kongqw/serialportlibrary/SerialPortManager.java

@@ -15,11 +15,12 @@
 import java.io.FileOutputStream;
 import java.io.IOException;
 
+
 /**
  * Created by Kongqw on 2017/11/13.
+ * Updated by wenshuoc on 2021/04/13.
  * SerialPortManager
  */
-
 public class SerialPortManager extends SerialPort {
 
     private static final String TAG = SerialPortManager.class.getSimpleName();
@@ -33,6 +34,16 @@ public class SerialPortManager extends SerialPort {
     private Handler mSendingHandler;
     private SerialPortReadThread mSerialPortReadThread;
 
+    private final int mReadDelay;
+
+    public SerialPortManager(int readDelay) {
+        mReadDelay = readDelay;
+    }
+
+    public SerialPortManager() {
+        this(0);
+    }
+
     /**
      * 打开串口
      *
@@ -180,7 +191,7 @@ private void stopSendThread() {
      * 开启接收消息的线程
      */
     private void startReadThread() {
-        mSerialPortReadThread = new SerialPortReadThread(mFileInputStream) {
+        mSerialPortReadThread = new SerialPortReadThread(mFileInputStream, mReadDelay) {
             @Override
             public void onDataReceived(byte[] bytes) {
                 if (null != mOnSerialPortDataListener) {

SerialPortLibrary/src/main/java/com/kongqw/serialportlibrary/thread/SerialPortReadThread.java

@@ -5,22 +5,30 @@
 import java.io.IOException;
 import java.io.InputStream;
 
+
 /**
  * Created by Kongqw on 2017/11/14.
+ * Updated by wenshuoc on 2021/04/13.
  * 串口消息读取线程
  */
-
 public abstract class SerialPortReadThread extends Thread {
 
     public abstract void onDataReceived(byte[] bytes);
 
     private static final String TAG = SerialPortReadThread.class.getSimpleName();
     private InputStream mInputStream;
-    private byte[] mReadBuffer;
+    private final byte[] mReadBuffer;
+    private final int mReadDelay;
 
-    public SerialPortReadThread(InputStream inputStream) {
+    /**
+     * 初始化读串口的线程
+     * @param inputStream 串口文件的输入流
+     * @param readDelay 读取过程中的延迟（ms）
+     */
+    public SerialPortReadThread(InputStream inputStream, int readDelay) {
         mInputStream = inputStream;
         mReadBuffer = new byte[1024];
+        mReadDelay = readDelay;
     }
 
     @Override
@@ -29,16 +37,24 @@ public void run() {
 
         while (!isInterrupted()) {
             try {
-                Log.i(TAG, "run: ");
-                while (mInputStream != null && mInputStream.available() == 0) {
-                    // Do nothing
+                if (mInputStream != null && mInputStream.available() == 0) {
+                    // 如果输入流有效但是没有输入值，便重新等待输入
+                    continue;
                 }
                 if (null == mInputStream) {
+                    // 输入流为null说明线程结束了，直接退出
                     return;
                 }
-                Thread.sleep(750);
-                int size = mInputStream.read(mReadBuffer);
+                // 输入流产生了输入值，可以开始读取
 
+                // 有的串口发送程序会产生一定的延迟，直接读取会导致串口消息分段
+                // 因此需要根据设置情况等待一段时间，保证发送端将消息发送完毕
+                if (mReadDelay > 0) {
+                    Thread.sleep(mReadDelay);
+                }
+
+                // 读取串口输入
+                int size = mInputStream.read(mReadBuffer);
                 if (-1 == size || 0 >= size) {
                     return;
                 }
@@ -49,7 +65,6 @@ public void run() {
 
                 Log.i(TAG, "run: readBytes = " + new String(readBytes));
                 onDataReceived(readBytes);
-
             } catch (IOException e) {
                 e.printStackTrace();
                 return;
@@ -78,6 +93,6 @@ public void release() {
                 e.printStackTrace();
             }
         }
-
     }
+
 }