处理：一个文件将写入，另一个不会

Question

我有一个奇怪的错误，我似乎真的找不到。情况是我有一个带有温度和光传感器的 arduino 板：光传感器用于查看某个房间是否“打开”（如果房间在一段时间内没有任何动作，灯就会熄灭）。我正在使用串行端口将数据推送到运行处理脚本的服务器。如果感应到的光高于某个阈值，则 arduino 板会推动“打开”，如果不是，则推动“关闭”。它还将温度推到换行符上。它每两秒重复一次。

使用 minicom 监控串行端口似乎一切正常。即使在脚本中，我输出的数据也确认一切正常。除了当我尝试将数据写入“open.txt”时，它似乎并非如此，而“temp.txt”工作正常（尝试使用 tail -f 两个文件，temp.txt 在 open.txt 时更新一直空着。

import processing.serial.*;
Serial mySerial;
PrintWriter openClosedFile;
 String openClosedFileName;
String currentOpenClosed;
PrintWriter temperatureFile;
String temperatureFileName;
int currentTemp;

void setup() 
{
   mySerial = new Serial(this, Serial.list()[0], 9600);
   openClosedFileName = "open.txt";
   openClosedFile = createWriter(openClosedFileName);
   currentOpenClosed = "CLOSED";
   temperatureFileName = "temp.txt";
   temperatureFile = createWriter(temperatureFileName);
   currentTemp = 0;
}

void draw() 
{
    if (mySerial.available() > 0 ) 
    {
         String value = mySerial.readStringUntil('\n');
         if ( value != null ) 
         {
           String timestamp = nf(day(),2) + "/" + nf(month(), 2) + "/" + year() + " " +         nf(hour(),2) + ":" + nf(minute(),2) + ":" + nf(second(),2);
       println(timestamp);
       value = trim(value);
           if (isNumeral(value))
             writeTemperature(value);
           else
             writeOpenClosed(value);
         }
    }
}

void writeOpenClosed(String val)
{
  print("OpenClosed: ");
  println(val);
  boolean writtenToFile = false;
  openClosedFile = createWriter(openClosedFileName);
  if (val.equals("OPEN") && !currentOpenClosed.equals("OPEN"))
  {
    println("val=OPEN and currentOpenClosed!=OPEN");
    openClosedFile.print("1");
    writtenToFile = true;
  }
  else if (val.equals("CLOSED") && !currentOpenClosed.equals("CLOSED"))
  { 
    println("val=CLOSED and currentOpenClosed!=CLOSED");
    openClosedFile.print("0");
    writtenToFile = true;
  }

  if (writtenToFile)
  {
    currentOpenClosed = val;
    openClosedFile.flush();
    openClosedFile.close();
    println("Written OpenClosed To File");
  }
}

void writeTemperature(String val)
{
  print("temperature: ");
  println(val);
  int intTemp = Integer.parseInt(val);
  if (intTemp != currentTemp)
  {
    currentTemp = intTemp;
    temperatureFile = createWriter(temperatureFileName);
    temperatureFile.print(val);
    temperatureFile.flush();
    temperatureFile.close();
    println("Written Temperature To File");
  }
}

boolean isNumeral(String val)
{
  for (int i = 0; i < val.length(); i++)
  {
    if (val.charAt(i) < 48 || val.charAt(i) > 57)
      return false;
  } 
  return true;
}

我预计会有一些语法错误（我之前没有使用过处理），但两个函数似乎都在做同样的事情......

一些示例输出：

Listening for transport dt_socket at address: 8212

30/10/2014 12:14:57
OpenClosed: CD
30/10/2014 12:14:57
temperature: 24
Written Temperature To File
30/10/2014 12:14:59
OpenClosed: CLOSED
30/10/2014 12:14:59
temperature: 25
Written Temperature To File
30/10/2014 12:15:01
OpenClosed: CLOSED
30/10/2014 12:15:01
temperature: 24
Written Temperature To File
30/10/2014 12:15:03
OpenClosed: CLOSED
30/10/2014 12:15:03
temperature: 25
Written Temperature To File
30/10/2014 12:15:05
OpenClosed: OPEN
val=OPEN and currentOpenClosed!=OPEN
Written OpenClosed To File
30/10/2014 12:15:05
temperature: 20
Written Temperature To File
30/10/2014 12:15:07
OpenClosed: OPEN
30/10/2014 12:15:07
temperature: 20
30/10/2014 12:15:09
OpenClosed: OPEN
30/10/2014 12:15:09
temperature: 20
^C

我没有看到什么，或者这里可能发生了什么？

Answer 1

好吧，我想我明白了，实际上是我笨。

对于最终的未来读者：致电

openClosedFile = createWriter(openClosedFileName);

在 writeOpenClosed() 函数中将打开文件，如果不需要写入任何内容，它将永远不会关闭。由于文件永远不会关闭（因为下次调用函数时会创建一个新对象），它不会释放要读取的文件。