Visitors Details question IO file handling in java

Question

VIP group of companies introduce a new shopping mall “Le Le” . To promote the mall they had approached “6th Event” a famous commercial event organizer to organize an event of lucky draw. The organizer has to collect name, phone and email id of all the visitors during promotion time and give it to the company.

The organizer needs an automated application and wants to store records in a text file called “visitors.txt”.

Records should to be stored in the following structure

Name1,phonenumber1,emailId1;Name2,phonenumber2,emailId2;

In a record, each attributes should be separated using comma (,) and records should be separated using semi colon (;).

Create a Java Application which has two classes called Main.java and FileManager.java

In FileManager class implement the following methods [method skeletons are given]

static public File createFile() – This method should create the file and return it.

static public void writeFile(File f, String record) – In the method, first parameter is the file reference in which records to be added and second parameter is a record, This record should append in the file. [Record should be as per the given format]

static public String[] readFile(File f) – This method accept file to be read, returns all records in the file.

[Note : Don’t modify the signature of the given methods]

In Main class use the following Input and Output statements and call the needed methods from FileManager class to manipulate files.

Enter Name

John

Enter Phone Number

1234567

Enter Email

[email protected]

Do you want to enter another record(yes/no)

yes

Enter Name

Grace

Enter Phone Number

98765412

Enter Email

[email protected]

Do you want to enter another record(yes/no)

no

Do you want to display all records(yes/no)

yes

John,1234567,[email protected]

Grace,98765412,[email protected]

Answer 1

    FileManager class

    //import necessary packages
import java.io.*;
import java.util.*;
 @SuppressWarnings("unchecked")//Do not delete this line
 public class FileManager 
 {

    static public File createFile()
    {
        File file =new File("visitors.txt");
try{      file.createNewFile();}
catch (IOException e)   
{  
e.printStackTrace();    //prints exception if any  
}      

    return file;
    }
   //change the return type as per the requirement    
    static public void writeFile(File f, String record)
    {    try { 


            BufferedWriter out = new BufferedWriter( 
                   new FileWriter(f.getName(), true)); 
            out.write(record+";"); 
            out.close(); 
        } 
        catch (IOException e) { 
            System.out.println("exception occoured" + e); 
        } 

    } 
    static public String[] readFile(File f)
    {

        List<String> tokens = new ArrayList<String>();
        try{
      File myObj = new File(f.getName());
      Scanner myReader = new Scanner(myObj);
      while (myReader.hasNextLine()) {

        // String [] arr= myReader.nextLine().split(";");
        // tokens = Arrays.asList(arr);
        tokens.add(myReader.nextLine());

      }

      myReader.close();
      }
       catch (FileNotFoundException e) {
      System.out.println("An error occurred.");
      e.printStackTrace();
    }
    String[] tokenArray = tokens.toArray(new String[0]);
    //=tokenArray.split(";");
    return tokenArray;
    }
 }


    Main class


    import java.util.*;
    import java.io.FileNotFoundException;
    //import necessary packages
    import java.io.File;
     @SuppressWarnings("unchecked")//Do not delete this line
    public class Main
    {
        public void abcd(){
            Scanner in = new Scanner(System.in);
            System.out.println("Enter Name");
            String name=in.next();
            System.out.println("Enter Phone Number");
            long phone=in.nextLong();
            System.out.println("Enter Email");
            String id= in.next();
            FileManager f= new FileManager();
            File x =f.createFile();
            f.writeFile(x,name+","+phone+","+id);
            System.out.println("Do you want to enter another record(yes/no)");
            String choice=in.next();
            if(choice.equals("yes")){
                abcd();
            }
            if(choice.equals("no"))
           {String []q=f.readFile(x);
           String pl[]=q[0].split(";");
            for(int i=0;i<pl.length;i++)
            {
                System.out.println(pl[i]);
                   }

                    System.exit(0);
            }

        }

        public static void main(String[] args) 
        {
            Main asd=new Main();
            asd.abcd();



        }

    }

This program gives me desired output but not able to run all test cases.
Getting error could not append multiple files. Dont know is this.But it works perfectly on compiler. And you should at least try to code rather then simply asking someone to code.

Answer 2

 //all test case passed
 import java.io.*;
 import java.util.*;
 @SuppressWarnings("unchecked")//Do not delete this line
 public class FileManager 
 {
    
    static public File createFile()
    {
        File myObj = new File("visitors.txt");
        try{      
            if(new File("visitors.txt").isFile()==false)
                myObj.createNewFile();
        }
        catch (IOException e)   
        {  
        e.printStackTrace();    //prints exception if any  
        } 
        return myObj;//change the return type as per the requirement 
    }
    static public void writeFile (File f, String record)
    {
    try
    {
    
    FileWriter fw = new FileWriter(f.getName(),true); //the true will append the new data
    fw.write(record+"\n");//appends the string to the file
    fw.close();
    }
    catch(IOException ioe)
    {
        System.err.println("IOException: " + ioe.getMessage());
    }
        
    }
    static public String[] readFile(File f)
    {
        List<String> list=new ArrayList<String>();
        try{
            File myObj = new File(f.getName());
            Scanner myReader = new Scanner(myObj);
            while (myReader.hasNextLine()) {
                String str=myReader.nextLine();
                String[] parts = str.split(";");
                for (String part : parts) {
                    list.add(part);
                }
            }
            myReader.close();
            
        }
        catch(FileNotFoundException ex){}
        String[] strings = list.stream().toArray(String[]::new);
            return strings;
        //change the return type as per the requirement  
    }
 }