DatasetReader.java

package com.danielgauci;

import java.io.*;
import java.util.ArrayList;
import java.util.StringTokenizer;

/**
 * Created by daniel on 1/3/17.
 */
public class DatasetReader {

    private String mPath;

    public DatasetReader(String datasetPath) {
        this.mPath = datasetPath;
    }

    public ArrayList<Record> readDataset(){
        // Initialize list to contain dataset
        ArrayList<Record> dataset = new ArrayList<>();

        FileInputStream fileInputStream = null;
        InputStreamReader inputStreamReader = null;
        BufferedReader reader = null;

        try {
            // Setup file reader
            File file = new File(mPath);
            fileInputStream = new FileInputStream(file);
            inputStreamReader = new InputStreamReader(fileInputStream);
            reader = new BufferedReader(inputStreamReader);

            // Skip first line (since it only contains column names)
            reader.readLine();

            // Start reading file
            String line;
            while ((line = reader.readLine()) != null) {
                // Initialize string tokenizer to extract attributes
                StringTokenizer tokenizer = new StringTokenizer(line, ", ");

                // Initialize array containing attributes for record
                ArrayList<DiscreteAttribute> attributes = new ArrayList<>();

                // Extract attributes from line
                String outlook = tokenizer.nextToken();
                String temperature = tokenizer.nextToken();
                String humidity = tokenizer.nextToken();
                String wind = tokenizer.nextToken();
                String playTennis = tokenizer.nextToken();

                // Add Outlook attribute
                if(outlook.equalsIgnoreCase("overcast")) {
                    attributes.add(new DiscreteAttribute("Outlook", DiscreteAttribute.Overcast));
                }
                else if(outlook.equalsIgnoreCase("sunny")) {
                    attributes.add(new DiscreteAttribute("Outlook", DiscreteAttribute.Sunny));
                }
                else if(outlook.equalsIgnoreCase("rain")) {
                    attributes.add(new DiscreteAttribute("Outlook", DiscreteAttribute.Rain));
                }

                // Add Temperature attribute
                if(temperature.equalsIgnoreCase("hot")) {
                    attributes.add(new DiscreteAttribute("Temperature", DiscreteAttribute.Hot));
                }
                else if(temperature.equalsIgnoreCase("mild")) {
                    attributes.add(new DiscreteAttribute("Temperature", DiscreteAttribute.Mild));
                }
                else if(temperature.equalsIgnoreCase("cool")) {
                    attributes.add(new DiscreteAttribute("Temperature", DiscreteAttribute.Cool));
                }

                // Add Humidity attribute
                if(humidity.equalsIgnoreCase("high")) {
                    attributes.add(new DiscreteAttribute("Humidity", DiscreteAttribute.High));
                }
                else if(humidity.equalsIgnoreCase("normal")) {
                    attributes.add(new DiscreteAttribute("Humidity", DiscreteAttribute.Normal));
                }

                // Add Wind attribute
                if(wind.equalsIgnoreCase("weak")) {
                    attributes.add(new DiscreteAttribute("Wind", DiscreteAttribute.Weak));

                }
                else if(wind.equalsIgnoreCase("strong")) {
                    attributes.add(new DiscreteAttribute("Wind", DiscreteAttribute.Strong));
                }

                // Add Play Tennis attribute
                if(playTennis.equalsIgnoreCase("no")) {
                    attributes.add(new DiscreteAttribute("PlayTennis", DiscreteAttribute.PlayNo));
                }
                else if(playTennis.equalsIgnoreCase("yes")) {
                    attributes.add(new DiscreteAttribute("PlayTennis", DiscreteAttribute.PlayYes));
                }

                // Create record with attributes
                Record record = new Record();
                record.setAttributes(attributes);
                dataset.add(record);

            }
        } catch (IOException e){
            System.out.print(e.getMessage());
        } finally {
            try {
                // Close file readers
                if (reader != null) {
                    reader.close();
                }

                if (inputStreamReader != null) {
                    inputStreamReader.close();
                }

                if (fileInputStream != null) {
                    fileInputStream.close();
                }
            } catch (IOException e){
                System.out.print(e.getMessage());
            }
        }

        return dataset;
    }
}