java.lang.NumberFormatException: For input string when using scanner to read the file

Question

I am not sure why I am receiving this error and what's the fix to it in the following snippet of code:

        String srcFile=args[0];
        Scanner fileIn = new Scanner(srcFile);
        //    if (fileIn.isFile() && fileIn.canRead())

        CarDB carDatabase = new CarDB();
        while(fileIn.hasNext())
        {       
          String[] line = fileIn.nextLine().split(",");
          double mpg = Double.parseDouble(line[0]);
          int cylinders = Integer.parseInt(line[1]);
          int power = Integer.parseInt(line[2]);
          int year = Integer.parseInt(line[3]);
          int region = Integer.parseInt(line[4]);
          String makerName = line[5].trim();
          String carName = line[6].trim();

          carDatabase.addCar(makerName, carName, mpg, cylinders, power, year, region);// add car
          carDatabase.addMaker(makerName);//add maker to list

        }

and line 36 is : double mpg = Double.parseDouble(line[0]);

Error is:

java CarDBMain cars.txt 
java.lang.NumberFormatException: For input string: "cars.txt"
    at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1250)
    at java.lang.Double.parseDouble(Double.java:540)
    at CarDBMain.main(CarDBMain.java:36)

Akash Thakare · Accepted Answer · 2014-06-29 11:01:17Z

3

You are having this Scanner fileIn = new Scanner("cars.txt"); so your first line will be "cars.txt"

 Scanner fileIn = new Scanner(new File(srcFile));//Or probably path of file

Here create file and pass the commandline argument,means file path,to File constructor and pass that file to Scanner.

You are passing file name as String to Scanner.

Constructors

Scanner(File source)<---Takes File you want to read
Scanner(String source)<----Takes String you want to read
etc.

edited Jun 29, 2014 at 11:01

answered Jun 29, 2014 at 6:40

Akash Thakare

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4 Comments

Mona Jalal Over a year ago

Well, this is a project in which I believe we are not supposed to change that specific line. Can we incorporate this any other way?

Mona Jalal Over a year ago

well, isn't the file name a string?

Akash Thakare Over a year ago

But it will take that String as input while you want to pass file from which you are reading.

Mona Jalal Over a year ago

It worked for me. Thanks. Will be accepting the answer in 6 minutes :) Apparently it was a typo or possibly they wanted us to catch it somehow!

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