Create a tiny editor with maximum of 100 lines.

import java.io.*;
class TinyEdit
{
    public static void main(String args[]) throws IOException
    {
        // create a BufferedReader using System.in
        BufferedReader br = new BufferedReader(new
        InputStreamReader(System.in));
        String str[] = new String[100];
        System.out.println("Enter lines of text.");
        System.out.println("Enter 'stop' to quit.");
        for(int i=0; i<100; i++)
        {
            str[i] = br.readLine();
            if(str[i].equals("stop"))
            break;
        }
        System.out.println("\nHere is your file:");
        // display the lines
        for(int i=0; i<100; i++)
        {
            if(str[i].equals("stop"))
            break;
            System.out.println(str[i]);
        }
    }
}

Write a programe that create files using FileWriter and also use different form write method.

import java.io.*;
class FileWriterDemo
{
    public static void main(String args[]) throws Exception
    {
        String source = "Now is the time for all good men\n"
        + " to come to the aid of their country\n"
        + " and pay their due taxes.";
        char buffer[] = new char[source.length()];
        source.getChars(0, source.length(), buffer, 0);
        FileWriter f0 = new FileWriter("file1.txt");
        for (int i=0; i < buffer.length; i += 2)
        f0.write(buffer[i]);
        f0.close();
        FileWriter f1 = new FileWriter("file2.txt");
        f1.write(buffer);
        f1.close();
        FileWriter f2 = new FileWriter("file3.txt");
        f2.write(buffer,buffer.length-buffer.length/4,buffer.length/4);
        f2.close();
    }
}

Write a java programe that reads itself as one charecter at a time using FileReader class.

import java.io.*;
class FileReaderDemo1
{
    public static void main(String args[]) throws Exception
    {
        FileReader fr = new FileReader("FileReaderDemo.java");
        BufferedReader br = new BufferedReader(fr);
        int s;
        while((s = br.read()) != -1)
        {
            System.out.print((char)s);
        }
        fr.close();
    }
}

Write a java programe that reads itself as one line at a time.

import java.io.*;
class FileReaderDemo
{
    public static void main(String args[]) throws Exception
    {
        FileReader fr = new FileReader("FileReaderDemo.java");
        BufferedReader br = new BufferedReader(fr);
        String s;
        while((s = br.readLine()) != null)
        {
            System.out.println(s);
        }
        fr.close();
    }
}

Read a file as charecter and create another file that contains the contents of privious file.

import java.io.*;
class CopyFile
{
    public static void main(String args[]) throws IOException
    {
        int i;
        FileInputStream fin;
        FileOutputStream fout;
        try {
            // open input file
            try {
                fin = new FileInputStream("D:\\Book\\a.txt");
            }
            catch(FileNotFoundException e)
            {
                System.out.println("Input File Not Found");
                return;
            }
            // open output file
            try {
                fout = new FileOutputStream("D:\\Book\\b.txt");
            } catch(FileNotFoundException e)
            {
                System.out.println("Error Opening Output File");
                return;
            }
        } catch(ArrayIndexOutOfBoundsException e)
        {
            System.out.println("Usage: CopyFile From To");
            return;
        }
        // Copy File
        try {
            do {
                i = fin.read();
                if(i != -1) fout.write(i);
            } while(i != -1);
        }
        catch(IOException e)
        {
            System.out.println("File Error");
        }
        fin.close();
        fout.close();
    }
}

Write a java programe that reads itself and display on output.

import java.io.*;
class ShowFile
{
    public static void main(String args[]) throws IOException
    {
        int i;
        FileInputStream fin;
        try
        {
            fin = new FileInputStream("ShowFile.java");
        } catch(FileNotFoundException e)
        {
            System.out.println("File Not Found");
        return;
        } catch(ArrayIndexOutOfBoundsException e)
        {
            System.out.println("Usage: ShowFile File");
            return;
        }
        // read characters until EOF is encountered
        do
        {
            i = fin.read();
            if(i != -1) System.out.print((char) i);
        } while(i != -1);
        fin.close();
    }
}

Write a java programe that reads a file as one charecter at a time with espacific directory and display on output.

import java.io.*;
class ShowFile1
{
    public static void main(String args[]) throws IOException
    {
        int i;
        FileInputStream fin;
        try
        {
            fin = new FileInputStream("D:\\Book\\a.txt");
        } catch(FileNotFoundException e)
        {
            System.out.println("File Not Found");
        return;
        } catch(ArrayIndexOutOfBoundsException e)
        {
            System.out.println("Usage: ShowFile File");
            return;
        }
        // read characters until EOF is encountered
        do
        {
            i = fin.read();
            if(i != -1) System.out.print((char) i);
        } while(i != -1);
        fin.close();
    }
}