Java Program For File Operation - Create, Read And Search The File

// Create, Read, and search file Program

import java.util.*;

import java.io.*;

class StudentRec

{

int regNo;

String name;

int internalMarks;

void displayRecord()

{

System.out.print("RegNo.: " + regNo);

System.out.print("  Name: " + name);

System.out.println(" Internal marks: "+ internalMarks);

}

}

class CreateReadFile {

public static void main(String args[])

throws IOException {

int i,num;

int choice=0;

int searchRegNo=0;

String str="";

boolean flag=true;

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

StudentRec  record = new StudentRec();

while(flag)

{

System.out.println("\n   Menu");

System.out.println("1. Write File");

System.out.println("2. Search");

System.out.println("3. Display File");

System.out.println("4. Quit");

System.out.print("Enter your choice: ");

choice= Integer.parseInt(br.readLine());

switch(choice){

case 1:

                // Create a file.

                FileWriter fout = new FileWriter("test.txt");

               

                //Read data from Keyboard

                System.out.print("How many records? ");

                num= Integer.parseInt(br.readLine());

                for(i=0;i<num;i++)

                {

                System.out.print("enter student id: ");

                record.regNo= Integer.parseInt(br.readLine());

                System.out.print("Enter student name:");

                record.name=br.readLine();

                System.out.print("enter Internalmarks:");

record.internalMarks =Integer.parseInt(br.readLine());

                // Write to file. 

                fout.write(record.regNo+"\n");

                fout.write(record.name+"\n");

                fout.write(record.internalMarks+"\n");

                }

                fout.write("EOF");

                fout.close();

                System.out.println("File is created"); 

                break;

case 2: 

                System.out.print("enter search Id: ");

                searchRegNo = Integer.parseInt(br.readLine());

case 3:

                FileReader fin = new FileReader("test.txt");

                Scanner sc = new Scanner(fin);

                while(sc.hasNextInt())

                {

                //Read data from file

                record.regNo = sc.nextInt();

                record.name = sc.next();             

                record.internalMarks= sc.nextInt();

                if(choice==3)

                record.displayRecord();

                if(choice==2)if(record.regNo==searchRegNo)

                record.displayRecord();

                }

                str= sc.next();

                if(str.equals("EOF"))

                System.out.println("End of file");

                else System.out.println("File format error.");

                fin.close();

                break;

case 4:  flag=false;

                break;

default:System.out.println("Wrong Choice!!");

}

}

System.out.println("Program is over");

}