Raspberry PI Tomcat7 and Serial Port Communication using ISO8859-7 - raspberry-pi

Question

I am trying to relay a message from a Servlet to COM in raspberry pi on Tomcat 7.
I am using null cable between raspberry and my PCs to test.
I am using jssc API (Java Simple Serial Connector) for serial communication.
Raspberry pi is using JDK 1.8.0_65.
I am getting the message in UTF8 and I should output it in ISO8859-7.
Since UTF8 is a superset of ISO8859-7, the app that calls the servlet ensures all characters sent are legitimate for ISO8859-7.
My code:
package com.test.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.ResourceBundle;
import java.util.logging.Level;
import java.util.logging.Logger;
import jssc.*;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
#WebServlet(value = "/Relay", name = "Relay")
public class Relay extends HttpServlet {
static Logger app = null;
static {
app = Logger.getLogger("com.test.app");
}
protected void doGet(HttpServletRequest request,HttpServletResponse response) {
doPost(request, response);
}
protected void doPost(HttpServletRequest request,HttpServletResponse response) {
try {
request.setCharacterEncoding("ISO-8859-7");;
response.setCharacterEncoding("ISO-8859-7");
//request.setCharacterEncoding("UTF-8");
//response.setCharacterEncoding("UTF-8")
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String message = request.getParameter("message");
app.logp(Level.INFO, this.getClass().getCanonicalName(),"APP", message);
String[] portNames = SerialPortList.getPortNames();
app.logp(Level.INFO, this.getClass().getCanonicalName(),"APP", portNames.length+"");
for(int i = 0; i < portNames.length; i++){
applogp(Level.INFO, this.getClass().getCanonicalName(),"APP", portNames[i]);
byte[] msg = new byte[1024];
msg = message.getBytes("ISO-8859-7");
Charset utf8charset = Charset.forName("UTF-8");
Charset iso88597charset = Charset.forName("ISO-8859-7");
ByteBuffer inputBuffer = ByteBuffer.wrap(message.getBytes());
CharBuffer data = utf8charset.decode(inputBuffer);
ByteBuffer outputBuffer = iso88597charset.encode(data);
byte[] outputData = outputBuffer.array();
byte[] b1 = message.getBytes();
byte[] b2 = message.getBytes(Charset.forName("ISO-8859-7"));
byte[] b3 = message.getBytes(StandardCharsets.ISO_8859_1);
SerialPort serialPort = new SerialPort((portNames[i]));
try {
serialPort.openPort();
serialPort.setParams(SerialPort.BAUDRATE_9600,SerialPort.DATABITS_8, SerialPort.STOPBITS_1,SerialPort.PARITY_NONE);
serialPort.writeBytes(msg);
serialPort.writeBytes(message.getBytes());
serialPort.writeBytes(outputData);
serialPort.writeBytes(b1);
serialPort.writeBytes(b2);
serialPort.writeBytes(b3);
serialPort.closePort();
} catch (SerialPortException ex) {
app.logp(Level.INFO, this.getClass().getCanonicalName(),"APP", ex.getMessage());
out.write("NOK");
out.close();
}
}
out.write("OK");
out.close();
} catch (IOException e) {
app.logp(Level.INFO, this.getClass().getCanonicalName(),"APP", e.getMessage());
}
}
private static final long serialVersionUID = 1L;
}
The problem is that when I am testing I do not get valid output in putty.
putty output
I have configured putty to display ISO8859-7 characters.
Any for changes ?
What am I missing ?
Thanks in advance.

Answer 1

I tried to divide the problem by producing the following code:
import java.io.UnsupportedEncodingException;
import jssc.SerialPort;
import jssc.SerialPortException;
public class SerialTest {
public static void main(String[] args) {
String message = "message μήνυμα";
if ( sendTextOnCom(message) ) {
System.out.println("SUCCESS MESSAGE SENT");
}
else{
System.out.println("FAIL MESSAGE NOT SENT");
}
}
private static boolean sendTextOnCom(String message) {
boolean isOverlaid = false;
SerialPort com = null;
try {
String comNo = "COM1"; // String comNo="/dev/ttyUSB0"; //when used in Raspberry
com = new SerialPort(comNo);
com.openPort();
com.setParams(9600, 8, 1, 0);
com.writeString(message);
com.writeBytes(message.getBytes("ISO-8859-7"));
com.closePort();
isOverlaid = true;
}
catch (SerialPortException ex) {
System.out.println("[ERROR] COM ERROR SENDING MESSAGE");
isOverlaid = false;
try {
com.closePort();
} catch (SerialPortException e) {
e.printStackTrace();
}
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return isOverlaid;
}
}
The code is working normally in Windows 7 64bit and it is producing output in putty with the right characters.
When I compile and run the same code in raspberry PI the output in putty is not showing the valid characters.
I tend to think that it's a raspberry PI configuration issue.