Java get properties to a text file

Question

In my engine I write the properties of an object to a file (position, scale, obj model and texture) at the moment I only get the position, how can I tell the program to also look for, scale, the obj file and the texture?

This is my code at the moment:

private void load_ExampleWorld()
{   
    try
    {   
        ProcessCoords file = new ProcessCoords(file_name);
        String[] aryLines = file.OpenFile();

        int i;
        for (i = 0; i < aryLines.length; i++)
        {
            System.out.println(aryLines[i]);                    

             if(aryLines[i].startsWith("model")) {
                    String Arguments = aryLines[i].substring(aryLines[i].indexOf(":")+1, aryLines[i].length());
                    String[] ArgArray = Arguments.substring(1, Arguments.length() - 2).split(" ");


                    World_Object_1(Double.parseDouble(ArgArray[0]),
                                   Double.parseDouble(ArgArray[1]),
                                   Double.parseDouble(ArgArray[2]),

                            0.5f,0.5f,0.5f,
                            "cube.obj","cubeTestTexture.png","diffuse_NRM.jpg","diffuse_DISP.jpg");
             }
        }
    }
    catch(IOException e) {
        System.out.println(e.getMessage());
        }
}

The program already gets the position but I seem not to be able to tell him to get the other informations.

in the text file it will look something like this (example):

model:(-3.979997 0.0 0.38)(0.5 0.5 0.5) cube.obj cubeTestTexture.png diffuse_NRM.jpg diffuse_DISP.jpg

Can someone explain to me how this can be achieved because I seem no to be able to wrap my head around it.. thanks for your help!

Here's the ProcessCoords Class:

public class ProcessCoords 
{   
    private String path;
    private boolean append_to_file = false; 

    public ProcessCoords (String file_path)
    {
        path = file_path;
    }

    public ProcessCoords(String file_path, boolean append_value)
    {
        path = file_path;
        append_to_file = append_value;
    }

    public String[] OpenFile() throws IOException
    {       
        FileReader fr = new FileReader(path);
        BufferedReader textReader = new BufferedReader(fr);

        int numberOfLines = readLines();
        String[] textData = new String[numberOfLines];

        int i;

        for (i=0; i < numberOfLines; i++)
        {
            textData[i] = textReader.readLine();
        }

        textReader.close();
        return textData;
    }   

    public void writeToFile(String textLine) throws IOException
    {
        FileWriter write = new FileWriter(path, append_to_file);
        PrintWriter print_line = new PrintWriter(write);

        print_line.printf("%s" + "%n", textLine);
        print_line.close();
    }

    int readLines() throws IOException
    {
        FileReader file_to_read = new FileReader(path);
        BufferedReader bf = new BufferedReader(file_to_read);

        String aLine;
        int numberOfLines = 0;

        while ((aLine = bf.readLine()) != null)
        {
            numberOfLines++;
        }
        bf.close();

        return numberOfLines;   
    }
}

Answer 1

Will try that out, thanks! Sorry I've totally forgot about ProcessCoords I have added the code in my question.. but as I remember it uses the java standart classes - please tell me if there might be something wrong or missing in the ProcessCoords class I wouldn't be sure myself..?

The method OpenFile() can return a String[] even without a call to readLines() (which unnecessarily opens the same file for a second time):

public String[] OpenFile() throws IOException {
    FileReader fr = new FileReader(path);
    BufferedReader textReader = new BufferedReader(fr);
    String line;
    List<String> textData = new List<>();

    while((line = textReader.readLine()) != null) {
        textData.add(line);
    }

    textReader.close();
    fr.close();

    return textData.toArray(new String[0]);
}

Apart from that, everything seems to be fine.

Answer 2

If you need to do it without using any other libraries (as Augusto suggested in his answer), you might want to consider using regular expressions. I do not know how your class ProcessCoords reads the properties file, so I'll be using standard Java classes in this example.

try (FileReader fr = new FileReader("file.txt"); BufferedReader in = new BufferedReader(fr);) {
    // read all lines from the given file
    String line;
    List<String> lines = new ArrayList<>();
    while ((line = in.readLine()) != null) {
        lines.add(line);
    }

    // process the lines
    for (int i = 0; i < lines.size(); i++) {
        String current = lines.get(i);

        // print the current line to the console output
        System.out.println(current);

        if (current.startsWith("model:")) {
            String args = current.substring("model:".length());
            Pattern pattern = Pattern
                    .compile("\\((-?\\d+\\.\\d+) (-?\\d+\\.\\d+) (-?\\d+\\.\\d+)\\)\\((-?\\d+\\.\\d+) (-?\\d+\\.\\d+) (-?\\d+\\.\\d+)\\) (.+?\\.obj) (.+?\\.png) (.+?\\.jpg) (.+?\\.jpg)");
            Matcher matcher = pattern.matcher(args);

            if (!matcher.matches()) {
                System.out.println("illegal argument format");
                continue;
            }

            double xCoord = Double.parseDouble(matcher.group(1));
            double yCoord = Double.parseDouble(matcher.group(2));
            double zCoord = Double.parseDouble(matcher.group(3));

            double xScale = Double.parseDouble(matcher.group(4));
            double yScale = Double.parseDouble(matcher.group(5));
            double zScale = Double.parseDouble(matcher.group(6));

            String modelFile = matcher.group(7);
            String textureFile = matcher.group(8);
            String diffuseNrmFile = matcher.group(9);
            String diffuseDispFile = matcher.group(10);

            World_Object_1(xCoord, yCoord, zCoord,
                           xScale, yScale, zScale,
                           modelFile, textureFile, diffuseNrmFile, diffuseDispFile);
        }
    }
} catch (IOException e) {
    e.printStackTrace();
}

If you want to get detailed information on the regular expression that was used, you can check it out here.

Answer 3

Why don't you use a library for config files? There's an excelent one made by typesafe called config. Also, you could use a properties file that can be easily read by the Properties class.