Pembahasan kali ini mirip dengan pembahasan sebelumnya. Hanya saja kali ini kita akan menggunakan class berbeda dari sebelumnya, walaupun tujuannya sama, yaitu class FileWriter untuk membuat/membuka file text, class BufferedWriter untuk menulis string ke dalam file text, class FileReader untuk membaca file text, dan BufferedReader untuk membaca string pada file text.

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versi satu

import java.io.*;
import java.util.Random;
class TulisBacaFile
{   
     static void tulisKeFile(String note)
    {   FileWriter fw;
        BufferedWriter bw = null;
        try
        {   fw = new FileWriter(note);
            bw = new BufferedWriter(fw);
            Random r = new Random();
            int x=0;
            String str=null;
            for(int i=0;i<5;i++)
            {   x = r.nextInt(30)+10;
                str = Integer.toString(x);
                bw.write(str+"\r\n");
                //bw.newLine();
            }
            str = Integer.toString(x+5);
            bw.write(str);
        } catch(IOException e)
        {   System.err.println("File writing error");
        } finally
        {   try
            {   if(bw != null)
                {   bw.flush();
                    bw.close();
                }
            } catch(IOException e)
            {   System.err.println(e);
            }
        }
    }
    
    static void bacaFile(String note)
    {   String str;
        int x, jml=0, n=0;
        try
        {   FileReader fr = new FileReader(note);
            BufferedReader br = new BufferedReader(fr);
            while((str=br.readLine()) != null)
            {   x = Integer.parseInt(str);
                System.out.println(x);
                jml+=x;
                n++;
            }
            br.close();
        } catch(IOException e)
        {   System.err.println("File read error");
        }
        double rata = (double) jml/n;
        System.out.println("Jumlah : "+jml+"\nRata-rata : "+rata);
    }
    
   public static void main(String[] args)
    {   tulisKeFile("coba1.txt");
        bacaFile("coba1.txt");
    }
    
    
}

---

versi dua

import java.io.*;
import java.util.Random;
class TxtIO
{   public static void main(String[] args)
    {   new TxtIO().tulisKeFile("coba1.txt");
        new TxtIO().bacaFile("coba1.txt");
    }
    void tulisKeFile(String note)
    {   FileWriter fw;
        BufferedWriter bw = null;
        try
        {   fw = new FileWriter(note);
            bw = new BufferedWriter(fw);
            Random r = new Random();
            int x=0;
            String str=null;
            for(int i=0;i<5;i++)
            {   x = r.nextInt(30)+10;
                str = Integer.toString(x);
                bw.write(str+"\r\n");
                //bw.newLine();
            }
            str = Integer.toString(x+5);
            bw.write(str);
        } catch(IOException e)
        {   System.err.println("File writing error");
        } finally
        {   try
            {   if(bw != null)
                {   bw.flush();
                    bw.close();
                }
            } catch(IOException e)
            {   System.err.println(e);
            }
        }
    }
    void bacaFile(String note)
    {   String str;
        int x, jml=0, n=0;
        try
        {   FileReader fr = new FileReader(note);
            BufferedReader br = new BufferedReader(fr);
            while((str=br.readLine()) != null)
            {   x = Integer.parseInt(str);
                System.out.println(x);
                jml+=x;
                n++;
            }
            br.close();
        } catch(IOException e)
        {   System.err.println("File read error");
        }
        double rata = (double) jml/n;
        System.out.println("Jumlah : "+jml+"\nRata-rata : "+rata);
    }
}

---

versi sederhana

import java.io.*;
class TulisBacaFile
{   
   public static void main(String[] args)
    {   
       String str;
       FileWriter fw;
       BufferedWriter bw;
       try
       {    fw = new FileWriter("coba2.txt");
            bw = new BufferedWriter(fw);
            bw.write("baris kesatu"+"\r\n");
            bw.write("baris kedua"+"\r\n");
            bw.write("baris ketiga\r\n");
            bw.write("baris keempat\r\n");
            bw.flush();
            bw.close();
        } catch(IOException e)
        {   System.err.println("Kesalahan pada penulisan text ke File");
        }
       
       FileReader fr; 
       BufferedReader br;
       try
       {
            fr = new FileReader("coba2.txt");
            br = new BufferedReader(fr);
            while((str=br.readLine()) != null)
            {   
                System.out.println(str);
            }
            br.close();
        } catch(IOException e)
        {   System.err.println("Kesalahan pada pembacaan file text");
        }
    }
}

hasil yang tampil di layar:
baris kesatu
baris kedua
baris ketiga
baris keempat