What's best way to use delim in Java IO from File

Question

I have a input file formatted in below.

ders : bilgisayargiris
hoca : erdogan
kod : 101
akts : 5
gtukred : 3
donem : 1
info : bu derste bilgisayar  falan .Also ogretiliyor confusing,blah,words,blah
Also ogretiliyor someshit.
soru : flip-flop devre nedir
cevap : erdoz
-

Basically i am reading a file with txt filled like this , getting right sides of colons and assigning them to my data in class. Character "-" used as an indicator that file is going for another information struct/piece.

Here's part of code i am struggling with below.

public void read(){
    className = this.getClass().getSimpleName();
    className = className + ".txt";
    openFile(className);

    readFile();

    System.out.println(className);
    closeFile();

}

public void openFile(String filer){
    try{
        scan =  new Scanner(new File("/home/paypaytr/IdeaProjects/yallah/src/a.txt")); //test purposes

    }
    catch (Exception e){
        System.out.println(className+"couldnt found.");
        //some safe quit mechanicsm
    }

}



 public void readFile(){
        while (scan.hasNextLine()){
            if(scan.nextLine()=="ders"){
                scan.nextLine(); //this is for skipping ":" but would love to delim it.
               name = scan.nextLine();
            }
            else if(scan.nextLine()=="hoca"){
                scan.nextLine(); //this is for skipping ":" but would love to delim it.
                tutor = scan.nextLine();
            }
            else if(scan.nextLine()=="kod"){
                scan.nextLine(); //this is for skipping ":" but would love to delim it.
                code = scan.nextInt();
            }
            else if(scan.nextLine()=="akts"){
                scan.nextLine(); //this is for skipping ":" but would love to delim it.
                akts = scan.nextInt();
            }
            else if(scan.nextLine()=="gtukred"){
                scan.nextLine(); //this is for skipping ":" but would love to delim it.
                gtukred = scan.nextInt();
            } else if(scan.nextLine()=="donem"){
                scan.nextLine(); //this is for skipping ":" but would love to delim it.
                donem = scan.nextInt();
            }
            else if(scan.nextLine()=="info"){
                scan.nextLine(); //this is for skipping ":" but would love to delim it.
                while(scan.nextLine()!="soru")
                info += scan.nextLine();
            }
            else if(scan.nextLine()=="soru"){
                scan.nextLine(); //this is for skipping ":" but would love to delim it.
                soru = scan.nextLine();
            }
            else if(scan.nextLine()=="cevap"){
                scan.nextLine(); //this is for skipping ":" but would love to delim it.
                cevap = scan.nextLine();
            }


        }
    }
public void closeFile(){
    scan.close();
}

Can someone please help ?

Answer 1

You can try using: BufferedReader with readLine

import java.io.*;  
public class BufferedReaderExample {  
    public static void main(String args[])throws Exception{    
          FileReader fr=new FileReader("D:\\testout.txt");    
          BufferedReader br=new BufferedReader(fr);    

          String line;   

          while ((line = br.readLine()) != null)  //Checks what in C++ you do EOF
          {

           line = line.substring(line.indexOf(":")+1);  //Here I am just implementing, how to print string after ":", you can process the string stored in variable line as per your convenience

           System.out.print(line);  
          }  
          br.close();    
          fr.close();    
    }    
}  

I hope you got the idea, you can accept the answer and close the question if it helped.

Answer 2

You can try FileReader

String p = ":";
    FileReader fr = new FileReader(new File("C:\\raw.txt"));
    BufferedReader br = new BufferedReader(fr);
    long startT = System.currentTimeMillis();
    String val = null;
    String[] finalAr = new String[1048576];
    while(br.ready()){
        finalAr[n] = br.readLine();
        n++;
    }
    for(int i = 1; i < finalAr.length; i++){
        if(finalAr[i].contains(p)) {
            System.out.println(finalAr[i].split(",")[1]);
        }
    }

Answer 3

I would recommend that you make this simpler.

Read each line as a String in its entirety. Deal with the tokenizing and parsing after you have the line in memory.

You can look for '#' in the first character and ignore what comes after as a comment.

You can look for '-' in the first character to indicate a new structure.

You can ignore blank lines.

You can split anything else that comes along using the String.split(":") method to get the key/value pair.

You should also consider something that is well understood, like .properties files, YAML, or JSON. Why invent a new one?

Answer 4

I suggest you to use the BufferedReader class which implement a readLine() method, that'll ease your work.

Example right here.

The line readed can then be splited using the split(":") method of a string object.

Example right here.

Answer 5

By default, Scanner uses whitespace to separate tokens. You have to set another delimiter: scan.useDelimiter("\\s*:\\s*")

Next point is, that you usually cannot compare Strings with ==, you have to use equals().