不兼容的类型：String []无法转换为String

Question

I'm being completely beaten up by types in Java.

I have coordinates in a txt file, which ultimately I want to format into an array of these co-ordinates, with each array item being a double.

Each line of my txt file looks like so:

13.716              , 6.576600074768066  

Currently, I'm trying to split this line into an array of two Strings, which I will then try and parse into doubles, but I keep getting the error in the title. Where am I going wrong?

Any other better approaches on converting my Arraylist of Strings to a formatted list of double coordinates would be great, like so

[[0,1], [0,2], 0,4]

Code:

 public static String[] getFileContents(String path) throws FileNotFoundException, IOException
    {
        InputStream in = new FileInputStream(new File(path));
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));

        List<String> data = new ArrayList<String>();
        StringBuilder out = new StringBuilder();
        String line;
//        Skips 1376 characters before accessing data
        reader.skip(1378);
        while ((line = reader.readLine()) != null) {            
                data.add(line);
//                System.out.println(line);
        }  

        for (int i=0; i < data.size(); i++){
            data.set(i, data.get(i).split(","));
        }
//        String[] dataArr = data.toArray(new String[data.size()]);
//        Test that dataArr[0] is correct
//        System.out.println(data.size()); 
//        List<String> formattedData = new ArrayList<String>();
//        for (int i = 0; i < data.size(); i++){
//            formattedData.add(dataArr[i].split(","));
//        }
        reader.close(); 
        return dataArr;
    }

Answer 1

The split(",") method return array of string string[] and you can't set string by array of string.

Crate point class with let lan double variabels and then create array of this point and them fill them with data from reading each line:

class Point{
    double lat;
    double len;
    Point(double lat, double len){
        this.lat = lat;
        this.len = len;
    }
}

And then use this class in your code:

 public static String[] getFileContents(String path) throws FileNotFoundException, IOException
    {
        InputStream in = new FileInputStream(new File(path));
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));

        List<String> data = new ArrayList<String>();
        StringBuilder out = new StringBuilder();
        String line;
//        Skips 1376 characters before accessing data
        reader.skip(1378);
        while ((line = reader.readLine()) != null) {            
                data.add(line);
//                System.out.println(line);
        }  
        List<Point> points = new ArrayList<Point>();
        for (int i=0; i < data.size(); i++){
            double lat =  Double.parseDouble(data.get(i).split(",")[0]);

            double len =  Double.parseDouble(data.get(i).split(",")[1]);
            points.add(new Point(lat, len));
            //data.set(i, data.get(i).split(","));
        }
//        String[] dataArr = data.toArray(new String[data.size()]);
//        Test that dataArr[0] is correct
//        System.out.println(data.size()); 
//        List<String> formattedData = new ArrayList<String>();
//        for (int i = 0; i < data.size(); i++){
//            formattedData.add(dataArr[i].split(","));
//        }
        reader.close(); 
        return dataArr;
    }

Answer 2

you can update your while loop like this

while ((line = reader.readLine()) != null) {
    String[] splits = line.split(",");
    for(String s : splits) {
        data.add(s);
    }
}