A Practical Java serial communication program that sends/receives data from the serial port COM1

This article mainly provides a practical Java serial communication program for discussion and learning.

/*************************************** ***
* Program file name: sendcomm. Java
* Function: send data from the serial port COM1
**************************************** **/
Import java. AWT .*;
Import java. AWT. event .*;
Import java. Io .*;
Import java. util .*;
Import javax. Comm .*;

Class s_frame extends frame implements runnable, actionlistener
{
/* Detect available communication port categories in the system */
Static commp ortidentifier portid;
/* Enumeration is an enumeration class, in util */
Static enumeration portlist;
Outputstream;
/* Serial port of RS-232 */
SerialPort;
Thread readthread;
Panel P = new Panel ();
Textfield in_message = new textfield ("enable COM1, baud rate 9600, data bit 8, stop bit 1 .");
Textarea out_message = new textarea ();
Button btnopen = new button ("Open the serial port and send data ");
Button btnclose = new button ("Close the serial port and stop sending data ");
Byte data [] = new byte [10240];
/* Set the flag to determine whether to disable the serial port */
Boolean mark;

/* Arrange the form */
S_frame ()
{Super ("sending data via serial port ");
Setsize (200,200 );
Setvisible (true );
Add (out_message, "center ");
Add (P, "North ");
P. Add (btnopen );
P. Add (btnclose );
Add (in_message, "South ");
Btnopen. addactionlistener (this );
Btnclose. addactionlistener (this );
} // R_frame () End

/* Click the button to open the serial port .*/
Public void actionreceivmed (actionevent event ){
If (event. getsource () = btnclose ){
SerialPort. Close (); // close the serial port
Mark = true; // run () method used to abort a thread
In_message.settext ("Serial Port COM1 has been disabled, stop sending data .");
}
Else {mark = false;
/* Read data by byte from the shard area */
Data = out_message.gettext (). getbytes ();
/* Open the serial port */
Start ();
In_message.settext ("Serial Port COM1 is enabled, and data is being sent every 2 seconds .....");
}
} // Action=med () End

/* Open the serial port and call the thread to send data */
Public void start (){
/* Obtain all communication ports in the system */
Portlist = commp ortidentifier. getportidentifiers ();
/* Use the loop structure to find the serial port */
While (portlist. hasmoreelements ()){
/* Forcibly convert to communication port type */
Portid = (comatrix ortidentifier) portlist. nextelement ();
If (portid. getporttype () = comatrix ortidentifier. port_serial ){
If (portid. getname (). Equals ("COM1 ")){
/* Open the serial port */
Try {
SerialPort = (SerialPort) portid. Open ("readcomm", 2000 );
}
Catch (portinuseexception e ){}
/* Set the serial output stream */
Try {
Outputstream = SerialPort. getoutputstream ();
}
Catch (ioexception e ){}
} // If end
} // If end
} // While end
/* Call the thread to send data */
Try {
Readthread = new thread (this );
// The thread is responsible for sending data every time, sleeping for 2 seconds
Readthread. Start ();
}
Catch (exception e ){}
} // Start () End

/* Send data, and re-send after 2 seconds of hibernation */
Public void run (){
/* Set serial communication parameters */
Try {
SerialPort. setserialportparams (9600,
SerialPort. databits_8,
SerialPort. stopbits_1,
SerialPort. parity_none );
}
Catch (unsupportedcommoperationexception e ){}
/* Send data streams (send the data in the array data )*/
Try {
Outputstream. Write (data );
}
Catch (ioexception e ){}
/* Sleep for 2 seconds after the data is sent and resend */
Try {thread. Sleep (2000 );
If (mark)
{Return; // end the run method, resulting in thread death
}
Start ();
}
Catch (interruptedexception e ){}
} // Run () End
} // Class s_frame end

Public class sendcomm
{Public static void main (string ARGs [])
{S_frame s_win = new s_frame ();
S_win.addwindowlistener (New windowadapter ()
{Public void windowclosing (invalid wevent E)
{System. Exit (0 );}
});
S_win.pack ();
}
}

/*************************************** ***
* Program file name: readcomm. Java
* Function: receives data from the serial port COM1.
**************************************** **/
Import java. AWT .*;
Import java. AWT. event .*;
Import java. Io .*;
Import java. util .*;
Import javax. Comm .*;

Class r_frame extends frame implements runnable, actionlistener, serialporteventlistener
{
/* Detect available communication port categories in the system */
Static commp ortidentifier portid;
/* Enumeration is an enumeration class, in Java. util */
Static enumeration portlist;
Inputstream;
/* Declare the member variable of the RS-232 serial port */
SerialPort;
Thread readthread;
String STR = "";
Textfield out_message = new textfield ("the text box above shows the received data ");
Textarea in_message = new textarea ();
Button btnopen = new button ("open serial port ");

/* Create a form */
R_frame ()
{
Super ("Serial Port receiving data ");
Setsize (200,200 );
Setvisible (true );
Btnopen. addactionlistener (this );
Add (out_message, "South ");
Add (in_message, "center ");
Add (btnopen, "North ");
} // R_frame () End

/* Click the button to trigger the event: Open the serial port and listen to the serial port .*/
Public void actionreceivmed (actionevent event)
{
/* Obtain all communication ports in the system */
Portlist = commp ortidentifier. getportidentifiers ();
/* Use the loop structure to find the serial port */
While (portlist. hasmoreelements ()){
/* Forcibly convert to communication port type */
Portid = (comatrix ortidentifier) portlist. nextelement ();
If (portid. getporttype () = comatrix ortidentifier. port_serial ){
If (portid. getname (). Equals ("COM1 ")){
Try {
SerialPort = (SerialPort) portid. Open ("readcomm", 2000 );
Out_message.settext ("the port COM1 is enabled and receiving data .....");
}
Catch (portinuseexception e ){}

/* Set the serial port listener */
Try {
SerialPort. addeventlistener (this );
}
Catch (toomanylistenersexception e ){}
/* Listen to the serial port for data and trigger the serial port event */
SerialPort. yonyondataavailable (true );
} // If end
} // If end
} // While end
Readthread = new thread (this );
Readthread. Start (); // The thread is responsible for every 20 seconds of Data sleep received
} // Action=med () End

/* Sleep for 20 seconds after receiving data */
Public void run (){
Try {
Thread. Sleep (20000 );
}
Catch (interruptedexception e ){}
} // Run () End

/* Set the serial communication parameters for the events triggered by the serial port listener, read the data, and write the data to the serial port listener */
Public void serialevent (serialportevent event ){
/* Set serial communication parameters: baud rate, data bit, stop bit, and parity */
Try {
SerialPort. setserialportparams (9600,
SerialPort. databits_8,
SerialPort. stopbits_1,
SerialPort. parity_none );
}
Catch (unsupportedcommoperationexception e ){}
Byte [] readbuffer = new byte [20];
Try {
Inputstream = SerialPort. getinputstream ();
}
Catch (ioexception e ){}
Try {
/* Read data streams from the line */
While (inputstream. Available ()> 0 ){
Int numbytes = inputstream. Read (readbuffer );
} // While end
STR = new string (readbuffer );
/* The received data is stored in the Region */
In_message.append (STR + "/N ");
}
Catch (ioexception e ){}
} // Serialevent () End
} // Class r_frame end

Public class readcomm
{
Public static void main (string ARGs [])
{
/* Instantiate the Form class for receiving serial data */
R_frame r_win = new r_frame ();
/* Define the button function for the form adapter */
R_win.addwindowlistener (New windowadapter ()
{Public void windowclosing (invalid wevent E)
{System. Exit (0 );}
});
R_win.pack ();
}
}