Java - Files and I/O

package javaIO;

import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.util.List;
import java.util.Locale;

public class DemoHitungBatasSks
{

    public static void main(String[] xx)
    {
        BatasDao bd = new BatasDao();
        List<Batas> hasil = bd.bacaFile();

        Locale indonesia = new Locale("ID", "id");
        NumberFormat formatter = NumberFormat.getInstance(indonesia);
        ((DecimalFormat)formatter).applyPattern("0.00");

        System.out.println("+=========+=========+=====+");
        System.out.println("| IPK Min | IPK Max | SKS |");
        System.out.println("+=========+=========+=====+");

        for(Batas b : hasil)
        {
            System.out.print("|  ");
            System.out.print(formatter.format(b.getIpkMin()));
            System.out.print("  |  ");
            System.out.print(formatter.format(b.getIpkMax()));
            System.out.print("  |  ");
            System.out.print(b.getSks());
            System.out.println("   |");
        }
        System.out.println("+=========+=========+=====+");
    }

}


import java.math.BigDecimal;

public class Batas
{
    private BigDecimal ipkMin;
    private BigDecimal ipkMax;
    private Integer sks;

    public BigDecimal getIpkMin()
    {
        return ipkMin;
    }

    public void setIpkMin(BigDecimal ipk)
    {
        this.ipkMin = ipk;
    }

    public BigDecimal getIpkMax()
    {
        return ipkMax;
    }

    public void setIpkMax(BigDecimal ipk)
    {
        this.ipkMax = ipk;
    }

    public Integer getSks()
    {
        return sks;
    }

    public void setSks(Integer sks)
    {
        this.sks = sks;
    }
}

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.List;

public class BatasDao
{
    public List<Batas> bacaFile()
    {
        try
        {
            // 0. Object penampungan hasil
            List<Batas> hasil = new ArrayList<Batas>();

            // 1. Deklarasikan object file
            File f = new File("input" + File.separator + "batas.txt");

            /// 2. Buat reader
            FileReader fr = new FileReader(f);
            BufferedReader br = new BufferedReader(fr);

            // 3. Looping, selama ada data baca dan tampilkan
            String data = br.readLine();
            data = br.readLine();
            while(data != null)
            {
                // 3.a. Parsing data
                String[] kolom = data.split(",");
                BigDecimal ipkMin = new BigDecimal(kolom[0]);
                BigDecimal ipkMax = new BigDecimal(kolom[1]);
                Integer sks = Integer.parseInt(kolom[2]);

                // 3.b Masukkan ke object
                Batas b = new Batas();
                b.setIpkMin(ipkMin);
                b.setIpkMax(ipkMax);
                b.setSks(sks);

                // 3.c. Kumpulan object di hasil akhir
                hasil.add(b);

                data = br.readLine();
            }

            // 4. Setelah selesai diproses, tutup file
            br.close();

            // 5. Return hasil
            return hasil;
        } catch (Exception err) {
            System.out.println("Terjadi error : " + err.getMessage());
            return new ArrayList<Batas>();
        }
    }
}