I am using a terminal emulator library to create a terminal and then I use it to send the data entered over serial to a serial device. When the data is sent back I want to parse it and show the most important information to the user in an editText. Currently I receive byte arrays/chunks and I convert them to a string. When I get a \r or a \n I crete a new string and the process repeats. This is fine for most commands, however some commands return results over multiple lines like "show vlan" here:
When I loop through this I get a string for each line. The first would contain VLAN Name Status and Ports, as an example. So now I have a problem, how can I VLAN 1 has x ports active. They are in different strings. Here is the code and screenshot for a current easier command where I am interested in one line:
Handler viewHandler = new Handler();
Runnable updateView = new Runnable() {
#Override
public void run() {
mEmulatorView.invalidate();
if (statusBool == true) {
for (int i = 0; i < dataReceived.length(); i++) {
parseCommand = parseCommand + dataReceived.charAt(i);
if (dataReceived.charAt(i) == '\n' || dataReceived.charAt(i) == '\r'){
if(parseCommand.contains("KlasOS"))
{
String[] tokens = parseCommand.split("\\s{1,}");
final String ReceivedText = mReceiveBox.getText().toString() + " "
+ new String("Software Version: " + tokens[1] + "\n" );
runOnUiThread(new Runnable() {
public void run() {
mReceiveBox.setText(ReceivedText);
mReceiveBox.setSelection(ReceivedText.length());
}
});
}
parseCommand = "";
}
}
statusBool = false;
viewHandler.postDelayed(updateView, 1000);
}
}
};
Now I would like to change this so i can deal with multiple lines. Would the ebst way be to store strings if they contain certain information?
I need this outputted on the right hand editText:
"The following ports are on vlan 1: Fa1/0, fa1/1, fa1/2, fa1/3, fa1/4, fa1/5, fa1/6, fa1/7, fa1/8, fa1/9, fa1/10, fa1/11, Gi0"
Basically, you need a way to reliably detect the end of a command result. Then it boils down to sending your command, reading data from the device until you encounter the end of result, and finally parsing that result.
I would scan for the prompt (switch#) as you do in your own answer. Maybe your are even able to force the device to use a more peculiar character sequence, which is unlikely to occur in the regular output of commands and makes it easier to detect the end of a result. For example, you could try to configure the prompt to include a control character like ^G or ^L. Or if your users don't mind, you could always send a second command that emits such a sequence, for example, "show vlan; echo ^G".
You should also be prepared for command errors, which result in a different output, for example, more or fewer lines as expected or a totally different output format. A result may even contain both, a regular output and a warning or an error.
I solved this in a messy way with a boolean and a few strings. i made a method for appending strings.
if((parseCommand.contains("VLAN Name") && parseCommand.contains("Status")&& parseCommand.contains("Ports"))
|| ((ShowVlanAppend.contains("VLAN Name")&& ShowVlanAppend.contains("Status")&& ShowVlanAppend.contains("Ports"))))
{
commandParse();
if(finalCommandBool == true){
runOnUiThread(new Runnable() {
public void run() {
mReceiveBox.setText(finalCommand);
mReceiveBox.setSelection(finalCommand.length());
ShowVlanAppend = "";
finalCommand = "";
finalCommandBool = false;
}
});
}
}
public void commandParse()
{
if (!parseCommand.contains("switch#")){
ShowVlanAppend = ShowVlanAppend + parseCommand;
}
else{
finalCommand = ShowVlanAppend;
finalCommandBool = true;
}
}
Related
I have a login page and a sign up page in my program.
I want to run it only if the user says begin.
These pages are called in the main method of my class, and I have a speech recognizer class.
I want the program to continue only when String output.contains("begin") == true
I tried putting the Class.main(args) in my if(output.contains("begin") == true)) case, there was an unhandled exception, and when i surrounded that section with try and catch, it didn't work.
I was told that Inheriting and implementing the classes from my API will work, but I'm not quite sure how to do it.
final Microphone mic = new Microphone(FLACFileWriter.FLAC);
GSpeechDuplex duplex = new GSpeechDuplex("AIzaSyBOti4mM-6x9WDnZIjIeyEU21OpBXqWBgw");
duplex.setLanguage("en");
duplex.addResponseListener(new GSpeechResponseListener() {
String old_text = "";
public void onResponse(GoogleResponse gr) {
String output = gr.getResponse();
if (gr.getResponse() == null) {
this.old_text = response.getText();
if (this.old_text.contains("(")) {
this.old_text = this.old_text.substring(0,
this.old_text.indexOf('('));
}
System.out.println("Paragraph Line Added");
this.old_text = ( response.getText() + "\n" );
this.old_text = this.old_text.replace(")", "").replace("( ", "");
response.setText(this.old_text);
}
if (output.contains("(")) {
output = output.substring(0, output.indexOf('('));
}
if (!gr.getOtherPossibleResponses().isEmpty()) {
output = output + " (" + (String)
gr.getOtherPossibleResponses().get(0) + ")";
}
response.setText("");
response.append(this.old_text);
response.append(output);
System.out.println(output);
if(output.contains("begin") == true){
duplex.stopSpeechRecognition();
mic.close();
Trying_Different_Languages t = new Trying_Different_Languages();
frame.dispose();
}
}
});
Expect The program to begin when i say begin but
It it doesn't begin when I say begin.
The try and catch statements just help in error free compilation.
In a program there should exist only 1 public static void main(String[] args) method. That is the indicator which tells you there starts the program.
Instead of calling the main method you should add a different method which do the stuff you want at a specific point.
So in detail it can look like that:
public class SomeClass {
public static void someMethodName() {
//some stuff you want to execute
}
}
So and where you want to execute the code:
...
SomeClass.someMethodName(); //executes the stuff you want.
In this case it would work if you create different methods which do exactly that you need to do at a specific point.
I have built a Spring CLI app which communicates with a server in an async fashion. The server was given, I did not create it, basically my app is required to open a TCP socket and send a JSON through it, then it sends back a JSON. It is mandatory not to use CLI parameters, but instead in the callback of the request I want to show the user a set of options for which he needs to select by inserting the corresponding number on the CLI. Most probably I'm not doing right something, because after entering the command, I see spring> on the console (this is an expected behavior) and it will block the async callback unless I press something (nothing is printed to the CLI when I receive the callback unless I press a bunch of enters - this is unexpected). To read from the console so far I used JLine's command line, what I would like to achieve is that when I get the response from the server and the callback is served, the console is given to the thread on which the callback is running (I instantly print the contents of the callback to the console, and I'm able to read the input without any tricks).
Some code:
public void runReceiver(){
receiverThread = new Thread(() -> {
byte[] digit = null;
int nb;
Iterator<CommandListener> it;
CommandListener listener;
String message;
List<CommandListener> listenersToRemove = new ArrayList<>();
while (true) {
try {
nb = communicatorInput.readInt();
digit = new byte[nb];
communicatorInput.readFully(digit);
} catch (IOException e) {
e.printStackTrace();
}
it = listeners.iterator();
while (it.hasNext()){
listener = it.next();
if (digit != null && digit.length > 0) {
message = new String(digit);
// the message was not acknowledged
if(message.contains("NACK")){
try {
listener.onError(message);
if (listener.isDone()) {
listenersToRemove.add(listener);
}
} catch (Exception e){
e.printStackTrace();
}
} else try {
listener.onCompleted(message);
} catch (InvalidObjectException e){
Main.logger.debug(String.format("Response could not be parsed as %s", listener.getCommandType()));
} catch (Exception e){
e.printStackTrace();
}
if (listener.isDone()) {
listenersToRemove.add(listener);
}
}
}
listeners.removeAll(listenersToRemove);
}
}, "receiverThread");
receiverThread.setDaemon(true);
receiverThread.start();
Then a CLI command (it expects no input here):
#CliCommand(value="start", help = "Starts stuff")
public void start() throws IOException, InterruptedException {
// this method is passed to the thread with the listener
getAvailabilities().updateAvailabilities("all", "all", "all", someListener);
}
And the callback for that listener:
someListener = new CommandListener() {
private String source = "Start some listener";
#Override
public void onCompleted(String r) throws IOException {
System.out.println("Which would you like to start?");
getAvailabilities().printAvailableBrands();
String brandNumber = "";
while(Objects.equals(brandNumber, "")){
System.out.println("Please enter the number of the Brand: ");
//when the callback arrives here I still only see ">spring:" and I get nothing printed on the console
brandNumber = cr.readLine();
if(!isInputAllowed(brandNumber, getAvailabilities().AvailableBrands.size())){
brandNumber = "";
}
}
BrandName = getAvailabilities().AvailableBrands.get(Integer.parseInt(brandNumber) - 1);
//updating the availabilities narrows down the things I list to the console, so I send an update after every selection
getAvailabilities().updateAvailabilities("all", BrandName, "all", getInterfaceListener);
done = true;
}
This might slightly connect to the issue that sometimes while debugging the CLI in Idea, it gets whacky inputs, eg. when I insert start it says No such command as ar, and if I press enter again, it'll say (some of) the rest: No such command as stt.
The problem is here:
if (listener.isDone()) {
listenersToRemove.add(listener);
}
If you want your listeners to be executed asynchronously you should not check their completion right away on the same thread as it will most likely return false.
The issue you might be having is that your listeners schedule some task but have no time to finish it as you immediately remove them after the loop:
listeners.removeAll(listenersToRemove);
It is very hard to tell what your logic is but I guess in the next while iteration your list is empty.
I am programming a little server-client-programm, which sends a text from one client who is writing on a file, to the other clients with the same filename, and got the following error
But I am just sending an integer and no other characters...
Here's the code:
Server
String[] splitter = scanText.split("\n");
String length = splitter.length + "";
//sending scanText to clients
for (PrintWriter pw2 : userMap.get(filename) ) {
if(!pw2.equals(pw))
{
pw2.println(length + "\n" + scanText);
}
}
Client
class "UpdateInBackground" is a class which is in the Client-class
class UpdateInBackground extends Thread {
#Override
public void run() {
int lines; //to know how much lines are send from the server
String scanText;
while (!this.isInterrupted()) {
scanText = "";
lines = Integer.parseInt(sc.nextLine()); //here I get the error
while (lines-- > 0) {
scanText += sc.nextLine() + "\n";
}
output.setText(scanText);
}
}
}
#asparagus, please define sc in line sc.nextLine(), considering this is an object from class Scanner, I need to know the input. The question must be self explainable with the definitions of variables and what are the inputs.
In Class UpdateInBackground,
lines = Integer.parseInt(sc.nextLine());// here nextLine() is for any String , please refer documentation
Reason for NumberFormatException : You are converting the value to int, without knowing, what is getting as input.
Try to use exception handling, to know what types of errors, might just come, to avoid the program getting struck.
I have implmented JSSC API so I can communicate with the Com Port.
I send a command like "N\r\n"
and what i receive in a normal hyperterminal should look like this:
0100071CA79215021803164442180000
0100071C9F5415021803164514520000
0100071CDF5115022106142956600000
NOK
But when i do the same with the JSSC API i receive this (only the first code)
010
0071CA79
2150218
0316444
218
The Problem is that i randomly receive bit parts and at the end of the code i lose some parts. But thats not important i only need the first 12 digits of every code.
The Question is now how do i get the function to only receive the full line and not bitparts?
This is the receiving part of the class
class PortReader2 implements SerialPortEventListener {
#Override
public void serialEvent(SerialPortEvent event) {
if(event.isRXCHAR()&& event.getEventValue() > 2) {
try {
// получение ответа от порта
String receivedData = serialPort.readString();
System.out.println(receivedData.length() + ":" + receivedData);
}
catch (SerialPortException ex) {
System.out.println("Error in receiving response from port: " + ex);
}
}
}
}
This is the sending part
public void sendCodeCommand(SerialPort serialPort) {
// writing string to port
try {
Thread.sleep(3000);
serialPort.writeBytes("N\r\n".getBytes());
} catch (SerialPortException | InterruptedException ex) {
Logger.getLogger(ComPortSendReceive.class.getName()).log(Level.SEVERE, null, ex);
}
System.out.println("String wrote to port, waiting for response..");
}
To fix the stated problem you need to concatenate the strings you receive into another string that accumulates the string fragments you receive from the readString() function, which is in the serialEvent handler. Because it is it's owm thread it gets a certain amount of cpu time to get serial data so it effectively gets partial sequential reads of the serial port input data. So this example puts the partial inputs together to create the "whole" input.
String serialString;
So within the serialEvent handler:
try {
serialStringFragment = serialPort.readString();
serialString.concat(serialStringFragment);
}
Either the string you get from readString() or the accumulation string can be scanned for tokens like eol condition. For Example:
String [] dlLines = serialString.split("\r\n");
will break each line out to an element in the dlLines string array.
However I have found that if I have fixed length output from my target device this works better:
serialPort.readString(int bytecount);
inline with the write serial string, eliminating the serialEvent handler.
This is a bit contrived but In other words:
String expectedStringLength "0100071CA79215021803164442180000";
int serialstrlen = expectedStringLength.length();
So the serialstrlen should obviously become constants for each expected line.
serialPort.writeString("N\r\n");
serialPort.readString(serialstrlen+2); // assuming cr lf
should get you the first line.
Put the readString() in a loop, change serialstrelen argument value according to the expected strings. Check the strings for alternate content for error handling. This has worked for me.
I have written a program to monitor the status of some hard drives attached to a RAID on Linux. Through this program I execute several command line commands. An interesting error occurs though....the program runs for a good three minutes before it seems that it can no longer correctly execute the command it had been previously executing (for many iterations).
It spits out an array index error (my variable driveLetters[d]) because it appears to miss the drive somehow (even though it found it hundreds of times before).
Other things to note...if I tell it to reset int "d" to "0" if it exceeds the number of drives...the program won't crash and instead will just become stuck in an infinite loop.
Also, the time at which the program crashes varies. It doesn't appear to crash after a set number of intervals. Finally, I don't get any kind of memory leak errors.
Here is some of code that should reveal the error:
public static void scsi_generic() throws IOException, InterruptedException
{
int i =0;
int d =0;
int numberOfDrives = 8;
char driveLetters[] = {'b','c','d','e','f','g','h','i','j','k','l','m'};
String drive = "";
while (i <= numberOfDrives)
{
System.out.println("position 1");
List<String> commands = new ArrayList<String>();
commands.add("cat");
commands.add("/sys/class/scsi_generic/sg"+i+"/device/sas_address");
SystemCommandExecutor commandExecutor = new SystemCommandExecutor(commands);
int driveFound = commandExecutor.executeCommand();
if (driveFound == 0)
{
System.out.println("Folder: sg" + i + " was found." );
StringBuilder stdout = commandExecutor.getStandardOutputFromCommand();
String data = stdout.toString();
String sas = data.substring(11,12);
int sasA = Integer.parseInt(sas,16);
boolean matchedSG = false;
while (matchedSG == false)
{
System.out.println("position2");
List<String> lookSD = new ArrayList<String>();
lookSD.add("test");
lookSD.add("-d");
lookSD.add("/sys/class/scsi_generic/sg"+i+"/device/block:sd" + driveLetters[d]);
SystemCommandExecutor commandSearch = new SystemCommandExecutor(lookSD);
int sdFound = commandSearch.executeCommand();
StringBuilder stdout3 = commandSearch.getStandardOutputFromCommand();
StringBuilder stderr = commandSearch.getStandardErrorFromCommand();
String sdFound2 = stdout3.toString();
if (sdFound == 0)
{
matchedSG = true;
System.out.println("Found the SD drive.");
drive = "sd"+driveLetters[d];
System.out.println(sasA);
hdsas.set(sasA , sas);
d = 0;
i++;
loadDrives(drive , sasA);
}
/* else if (sdFound != )
{
System.out.println("Error:" + sdFound);
System.out.println(d+ " "+ i);
}
*/
else if ( d >= 8)
{
System.out.println("Drive letter: " + driveLetters[d]);
System.out.println("Int: " + i);
// System.out.println(sdFound2);
System.out.println("sd error: "+ sdFound);
// System.out.println(stderr);
//System.out.println(sdFound2 + " m");
}
else
{
d++;
}
}
}
else
{
System.out.println("Folder: sg" + i + " could not be found.");
i++;
}
d =0;
}
}
Any help or suggestions would be awesome! Thanks.
EDIT:
The solution I found was to use the java library for testing if a directory exists rather than doing it through the linux command line.
Ex:
File location = new File("directory");
if (location.exists())
{
}
No idea why it works and doesn't crash, where as the linux command line did after a short period of time, but it does.
This is no direct answer to your question, but it still might help you:
I often have to find bugs in code like yours (very long methods with "global" variables, that is, variables declared at the beginning of a method and used all over then). Just by refactoring the code properly (short methods with a single purpose each), the cause of the bug becomes immediately visible to me and is fixed within a second (while the refactoring itself takes much longer).
I guess that's what everyone trying to offer you help is doing anyway: Refactor your code (probably only in one's head) so that is (much) more easy to understand what's going on.
The solution I found was to use the java library for testing if a directory exists rather than doing it through the linux command line.
Ex:
File location = new File("directory");
if (location.exists())
{
}
No idea why it works and doesn't crash, where as the linux command line did after a short period of time, but it does.