Null Pointer Error: Can't Find Declaration Cause

Question

In Console:

Exception in thread "main" java.lang.NullPointerException at SimulatedReality.main(SimulatedReality.java:25)

Line 25 is "BecomesArray = ReadsLine.toCharArray();".

In my code, I am attempting to read off of a file and check all of its characters (or at least for first ten) to see if any are of the value one. I am trying to do this to reset the text of the document after being used once. The problem with the code is that there is a null-pointer error, caused by declaration problems (or, at least, that is what I heard). I couldn't find where this error was. Please and thank you for whoever helps me. I am a beginner, so explanation will be best if overly simplified.

File SRFile = new File("C:/Users/ThinkingBeing/Documents/SRFile.txt");

    SRFileWriter = new   
            FileWriter("C:/Users/ThinkingBeing/Documents/SRFile.txt");
    if(!SRFile.exists()){
            SRFile.createNewFile();
        SRFileWriter.write("000000");
        System.out.println("File now exists.");
    } else {
    for(int i=0;i<=5;i++){          
    SRFileReader = new BufferedReader(new FileReader(SRFile));      
    ReadsLine = SRFileReader.readLine();
    BecomesArray = ReadsLine.toCharArray(); 
    BasicChar = BecomesArray[i];
    if(BasicChar!='0'){         
        SRFileWriter.write("000000");
        System.out.println("File Off Of Counter. Counter Fixed.");
    }
    }
    SRFileWriter.close();
    SRFileReader.close();
    }

Answer 1

I think I found your issue (and please follow Java naming conventions).

SRFileReader = new BufferedReader(new FileReader(SRFile)); // <-- file reader once
ReadsLine = SRFileReader.readLine();
BecomesArray = ReadsLine.toCharArray(); 
FileWriter SRFileWriter = new FileWriter
    ("C:/Users/ThinkingBeing/Documents/SRFile.OUT.txt"); // <-- Don't write to 
                                       // your input file while you're reading it.

for(int i=0;i<(BecomesArray != null) ? BecomesArray.length : 0;i++){
  // SRFileReader = new BufferedReader(new FileReader(SRFile));      
  BasicChar = BecomesArray[i];
  if(!SRFile.exists()||BasicChar=='1'){
    // SRFile.createNewFile(); // <-- Would clear your input file.
    SRFileWriter.write("00BOOYTA"); // <-- which was also your output file.
  }
}
SRFileWriter.close();
SRFileReader.close();

Answer 2

Several possible problems...

It's possible your file has less than 10 lines.

Then readLine will return null and the next line will fail. Documentation here

ReadsLine = SRFileReader.readLine();
BecomesArray = ReadsLine.toCharArray(); 

Also you should probably make sure your file exists before you start reading from it.

if(!SRFile.exists()||BasicChar=='1'){

And lastly, I can't quite make out what you're trying to achieve just by reading your code. But there's definitely something off with the logic. I find it odd that BasicChar is the i-th character of the i-th line for each line.