处理字符串到整数的转换错误

Question

I have some simple Processing code that reads serial data coming in, writes it to a string and, depending on what is contained within that string, it converts the string to an int or char and executes some specific code.

My problem is that when I try to convert the data to an integer it either gives me an error or gives me a value of zero ( int(string) returns zero, Integer.parseInt(string) returns an error ). Below is the relevant portion of my code.

String serialreadbuffer;
int t = 0;
boolean STimer = false;

// Serial Message Display (From Controller)
if (myPort.available() > 0) 
{  // Check if data is available
  serialreadbuffer = myPort.readStringUntil('\n');         // read it and write to variable
  if (serialreadbuffer.charAt(0) == 'I')
  {
    SerialText.setText("INITIALIZED");
    t = 0;
    STimer = true;
  }
  else if (serialreadbuffer.charAt(0) == 'U')
  {
    SerialText.setText("UPDATED");
    t = 0;
    STimer = true;
  }
  else if (serialreadbuffer.charAt(0) == 'D')
  {
    SerialText.setText("DISABLED");
    t = 0;
    STimer = true;
  }
  else if (serialreadbuffer.charAt(0) == 'E')
  {
    SerialText.setText("SERIAL COMMUNICATION ERROR");
    t = 0;
    STimer = true;
  }
  else
  {
    int numberbuffer = Integer.parseInt(serialreadbuffer) * 60 / 6144;
    serialreadbuffer = str(numberbuffer);
    RPMText.setText(serialreadbuffer);
  }
}

Strangely enough, if I assign a string value directly to serialreadbuffer (ie serialreadbuffer = "6144") it will work, but if I get the same number from my serial port it gives me the following error:

NumberFormatException: For input string: "6144"

and it gives me that error for the following line:

int numberbuffer = Integer.parseInt(serialreadbuffer) * 60 / 6144;

I was also having a problem with the string.equals() compares (it would always return false, even if the strings were identical), however I got around this by converting the first character to char and using that to compare. Not sure if that is related to this issue or not.

I have scoured the internet and have found no help with this matter. I am not an experienced programmer, so maybe it's something obvious that I'm just not seeing. Your help is greatly appreciated.

Answer 1

trim the String before you parse it insetad of

int numberbuffer = Integer.parseInt(serialreadbuffer) * 60 / 6144;

do

int numberbuffer = Integer.parseInt(serialreadbuffer.trim()) * 60 / 6144;

you might have unprintable characters eg \\r in it.

Answer 2

There could be some space with the value. Try trimming the string before conversion.

Serialreadbuffer.trim()