Where is the error

Question

hi
i'm trying to creat Arraylist with objects then store this arraylist to file
when the program starts it will check if the file exist if yes it will load it and casted to array list
if not
creat new file and start new array list , but i get always different error
here is my codes :
public class Animal {
     private String name ;
     private int age ;
     public Animal(String name , int age){
          setName( name);
          setAge( age);
     public int getAge() {
          return age;
     public void setAge(int age) {
          this.age = age;
     public String getName() {
          return name;
     public void setName(String name) {
          this.name = name;
import java.io.File;
import java.util.ArrayList;
import java.util.Scanner;
public class Test {
      * @param args
     public static void main(String[] args) {
          String _CLN_File     ="C:"+File.separator+"Animal";
          File file;
          String name1 ,name2;
          int age1,age2;
          Animal temo ,rico;
          Scanner input = new Scanner(System.in);
          ArrayList<Animal> list;
          file = new File(_CLN_File);
          if(file.exists()){
               System.out.println("file exisits");
               list = (ArrayList) ReadFromDesk.readList(file);
          else{
               list = new ArrayList<Animal>();
               System.out.println("no file found");
               name1 =input.next();
               name2=input.next();
               age1=input.nextInt();
               age2=input.nextInt();
               temo = new Animal(name1,age1);
               rico = new Animal(name2,age2);
               list.add(temo);
               list.add(rico);
               WriteToDisk.writeList(file,_CLN_File,list);
          for(Animal st : list){
               System.out.println("name is "+st.getName());
               System.out.println("age is "+st.getAge());
import java.io.FileInputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.lang.NullPointerException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class ReadFromDesk {
     public ReadFromDesk(){}
     //will return any array list
     public static ArrayList readList (File file){
          FileInputStream   _arrListIn     = null;
          ObjectInputStream _arrListReadObj= null;
          try{
               _arrListIn = new FileInputStream(file);
               _arrListReadObj = new ObjectInputStream(_arrListIn);
               ArrayList temp = new ArrayList();
               temp = (ArrayList) _arrListReadObj.readObject();
               return temp;
               }catch (ClassNotFoundException cnfe) {
                    cnfe.printStackTrace();
               } catch (FileNotFoundException fnfe) {
                    fnfe.printStackTrace();
               } catch (IOException ioe) {
                    ioe.printStackTrace();
               }catch (NullPointerException npi){
                    npi.printStackTrace();
          finally{
               try {
                    _arrListReadObj.close();
                    _arrListIn.close();
                    } catch (IOException ioe) {
                         ioe.printStackTrace();
          return null;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
public class WriteToDisk {
     public WriteToDisk(){}
     //using generic so this method can take any type of arraylist as
     //parameter
     public static <E> void writeList(File file,
               String path,ArrayList <E> arrlist){
          FileOutputStream   _arrListOut      = null;
          ObjectOutputStream _arrListWriteObj = null;
          try{
               _arrListOut = new FileOutputStream(file);
               _arrListWriteObj = new ObjectOutputStream(_arrListOut);
               _arrListWriteObj.writeObject(arrlist);
               _arrListWriteObj.flush();
          catch (FileNotFoundException fnfe) {
               System.out.println("NotFound Ex");
          } catch (IOException ioe) {
               System.out.println("IO EX");
          }catch (NullPointerException npi){
               System.out.println("NULL EX");
          finally{
               try {
               _arrListWriteObj.close();
               _arrListOut.close();
               } catch (IOException ioe) {               
                    System.out.println("Finally Close EX");
}

Answer 1

thanks it works fine BUT here is part of my real program and i have a problem reading from file
package database;
import java.io.File;
import java.io.Serializable;
import java.util.ArrayList;
import exceptions.DuplicatedInput;
import exceptions.InvalidPasswordException;
import exceptions.NoObjectFoundException;
import model.Client;
import utilities.ListsUtil;
import utilities.ReadFromDesk;
public class ClientsList implements Serializable{
     private final String _CLN_File     ="C:"+File.separator+"clients";
     private File         _clientsF;
     private ArrayList <Client> _clientList;
     public ClientsList(){
          ReadFromDesk rfd = new ReadFromDesk();
          _clientsF = new File (_CLN_File);
          _clientList = new ArrayList<Client>();
          if (_clientsF.exists()){
               // i should also check if the file is not empty
               _clientList = rfd.readList(_clientsF);
     }//end constructor
     /* add client to list , test if the list is empty , client will be
      * added if the user name doesn't exists in the list.
     public void addClientToList(Client client)throws DuplicatedInput{
          if (_clientList.isEmpty()){
               _clientList.add(client);
          else{
               for(Client temp : _clientList){
                    if (temp.get_userName().equals(client.get_userName()))
                         throw new DuplicatedInput("username exists");
          //the following in case if the list is not empty and no dublicated input
          _clientList.add(client);
     public boolean checkUsername(String username){
          if (_clientList.isEmpty()){
                    return true;
          else{
                    for(Client temp : _clientList){
                         if (temp.get_userName().equals(username))
                              return false;
               return true;
     public Client logIn(String username,String password) throws NoObjectFoundException , InvalidPasswordException
          for(Client client : _clientList){
               //i could use one if statment and check both , but by this way
               //i can throw 2 different exception
               if (client.get_userName().equals(username)){
                    if (client.get_passWord().equals(password)){
                         return client;
                    else
                         throw new InvalidPasswordException ("invalid password");
          throw new NoObjectFoundException("ther is no client with this user name");
     public void saveClientList(){
          ListsUtil.saveList(_clientsF,_clientList);
package model;
import java.io.Serializable;
import java.util.ArrayList;
import exceptions.NoObjectFoundException;
import utilities.DateManager;
public class Client extends Group3 implements Serializable{
     private String _fName;
     private String _userName;
     private String _passWord;
     private String _passwordHint;
     private String _lastVisitDate;
     private char   _client_classification;
     private double _totalOrders;
     private double _lastOrder;
     private ArrayList <Product> _pasket; //create method to print this in text file
     public Client(String lName, String fName, String address,String phoneNum,
               String username, String password,String passwordHint){
          super (lName,address,phoneNum);
          set_fName(fName);
          set_userName(username);
          set_passWord(password);
          set_passwordHint(passwordHint);
          _pasket       = new ArrayList<Product>();
     public void addToPasket(Product product , int qty){
          product.set_priceWithQtyDis(qty);
          product.set_PriceWithoutDis(qty);
          _pasket.add(product);
    /*All Setters and Geters*/
     public ArrayList<Product> getPurchasedProducts()throws NoObjectFoundException
          if (!_pasket.isEmpty())
               return _pasket;
          else
               throw new NoObjectFoundException("Your Pasket is Empty");     
     public char get_client_classification() {
          return _client_classification;
     public void set_client_classification() {
          if (get_totalOrders() >=20000)
               _client_classification = 'A';
          else if (get_totalOrders() >=15000 && get_totalOrders() < 20000)
               _client_classification = 'B';
          else if (get_totalOrders() >=7500 && get_totalOrders() < 15000)
               _client_classification = 'C';
          else
               _client_classification = 'D';
     public double get_lastOrder() {
          return _lastOrder;
     public void set_lastOrder(double order) {
          _lastOrder = order;
     public double get_totalOrders() {
          return _totalOrders;
     public void set_totalOrders(double orders) {
          _totalOrders += orders;
     public String get_lastVisitDate() {
          return _lastVisitDate;
     public void set_lastVisitDate() {
          _lastVisitDate =DateManager.currentDate();
     public String get_fName() {
          return _fName;
     public void set_fName(String fname) {
          _fName = fname;
     public String get_passWord() {
          return _passWord;
     public void set_passWord(String word) {
          _passWord = word;
     public String get_passwordHint() {
          return _passwordHint;
     public void set_passwordHint(String hint) {
          _passwordHint = hint;
     public String get_userName() {
          return _userName;
     public void set_userName(String name) {
          _userName = name;
* this class will write any class that implements the interface "List"
package utilities;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.util.List;
public class WriteToDisk {
     public WriteToDisk(){}
     //using generic so this method can take any type of arraylist as
     //parameter
     public static <E> void writeList(File file,List <E> arrlist){
          FileOutputStream   _arrListOut      = null;
          ObjectOutputStream _arrListWriteObj = null;
          try{
               _arrListOut = new FileOutputStream(file);
               _arrListWriteObj = new ObjectOutputStream(_arrListOut);
               _arrListWriteObj.writeObject(arrlist);
               _arrListWriteObj.flush();
          catch (FileNotFoundException fnfe) {
            fnfe.printStackTrace();
            file.deleteOnExit();
          } catch (IOException ioe) {
            ioe.printStackTrace();
            file.deleteOnExit();
          }catch (NullPointerException npi){
               npi.printStackTrace();
               file.deleteOnExit();
          finally{
               try {
               _arrListWriteObj.close();
               _arrListOut.close();
               } catch (IOException ioe) {               
                    ioe.printStackTrace();
                    file.deleteOnExit();
package utilities;
import java.io.FileInputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.lang.NullPointerException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class ReadFromDesk {
     public ReadFromDesk(){}
     //will return any array list
     public <E>  ArrayList<E> readList (File file){
          FileInputStream   _arrListIn     = null;
          ObjectInputStream _arrListReadObj= null;
          try{
               _arrListIn = new FileInputStream(file);
               _arrListReadObj = new ObjectInputStream(_arrListIn);
               ArrayList <E>temp = new ArrayList<E>();
               temp = (ArrayList) _arrListReadObj.readObject();
               return temp;
               }catch (ClassNotFoundException cnfe) {
                    System.out.println("class n Ex");
               } catch (FileNotFoundException fnfe) {
                    System.out.println("file NotFound Ex");
               } catch (IOException ioe) {
                    System.out.println("io Ex");
               }catch (NullPointerException npi){
                    System.out.println("null Ex");
          finally{
               try {
                    _arrListReadObj.close();
                    _arrListIn.close();
                    } catch (IOException ioe) {
                         ioe.printStackTrace();
          return null;
     public static <E> List<E> deepCopy(List<E>dist , List<E>Source){
          Iterator <E> iter = Source.iterator();
          int counter =0;
          while (iter.hasNext()){
               dist.add(counter,Source.get(counter));
               counter++;
          return dist;
package utilities;
import java.io.File;
import java.rmi.server.UID;
import java.util.ArrayList;
import java.util.List;
import model.Group3;
import utilities.WriteToDisk;
import exceptions.NoObjectFoundException;
public class ListsUtil {
     public static <E> void saveList(File file ,
               ArrayList <E> arraylist)
          if (!arraylist.isEmpty())
               WriteToDisk.writeList(file,arraylist);
          else
               file.deleteOnExit();
     public static void removeFromList(List<Group3> list , UID id)throws NoObjectFoundException
          for(Group3 g3 : list){
               if(g3.get_IDENTIFIER().equals(id)){
                    list.remove(g3);
                    return;
          throw new NoObjectFoundException("error removing object");
package View;
import java.util.Scanner;
import model.Client;
import database.ClientsList;
//import database.ProductsList;
import exceptions.DuplicatedInput;
import exceptions.InvalidPasswordException;
import exceptions.NoObjectFoundException;
public class OnlineOrder {
     public static void main(String[] args) {
          String lName,  fName,  address, phoneNum, username ,  password,
          passwordHint;
          Client cast = null;
          ClientsList cList  = new ClientsList();
          //ProductsList pLists= new ProductsList();
          System.out.println("Welcome to Group3 Shop");
          System.out.printf("%s\n%s\n",
                    "1- New user",
                    "2- LogIn");
          int choice = 0;
          Scanner input = new Scanner(System.in);
          choice =input.nextInt();
          switch (choice){
               case 1 : System.out.println("please fill in :");
                          lName = input.next();
                          fName = input.next();
                          address=input.next();
                          phoneNum=input.next();
                          while (true){
                               boolean usernameExsit = false;
                               System.out.println("enterusername");
                               username = input.next();
                               usernameExsit = cList.checkUsername(username);
                               if (usernameExsit==true)
                                    break;
                          password = input.next();
                          passwordHint =input.next();
                          cast = new Client(lName,  fName,  address, phoneNum,
                                    username,  password, passwordHint);
                          break;
               case 2:
                    String user = input.next();
                    String pass = input.next();
                    try {
                         cast = cList.logIn(user,pass);
                    } catch (NoObjectFoundException e) {
                         // TODO Auto-generated catch block
                         System.out.println("no username");
                    } catch (InvalidPasswordException e) {
                         // TODO Auto-generated catch block
                         System.out.println("no pass");
                    break;
               default :
                    cast = new Client("wael","manar","imbaba","imbaba","imbaba","imbaba","imbaba");
          try {
               cList.addClientToList(cast);
          } catch (DuplicatedInput e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
          cList.saveClientList();
          System.out.printf("%s",cast.get_fName());
}