Telephone directory using linked list [closed]

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My program is about telephone directory I was use linked list I have problem in this code it doesn’t have syntax error but I can’t see the answer when I do search and list also I hope you to add update method

This is first class:

//-----------------------------------------------------------------------------------------
class tel  
{

       private static String name;
       private static String address;
       private static int phoneNo;
       private tel next;
       private tel prev;

       public tel(){
       }
     public tel(String name1,String address1 ,int phoneNo1)
     {
     name = name1 ;
     address = address1;
     phoneNo = phoneNo1; 
     }
   开发者_StackOverflow社区     public static String getName() {
                return name;
        }
        public void setName(String name1) {
                name = name1;
        }
        public static String getAddress() {
                return address;
        }
        public void setAddress(String address1) {
                address = address1;
        }
        public static int getPhoneNo() {
                return phoneNo;
        }
        public void setPhoneNo(int phoneNo1) {
               phoneNo = phoneNo1;
        }
         public tel getNext() {
                return next;
        }
        public void setNext(tel next1) {
                next = next1;
        }
         public tel getPrev() {
                return prev;
        }
        public void setPrev(tel prev1) {
                prev = prev1;
        }
       public  void  display()
        {
         System.out.println("Name : " + getName() + " PhoneNo : " + getPhoneNo() + " Address : " + getAddress());
        }
        }  
//-------------------------------------------------------------------------------------------------------------------
//2ed class
public class telList {
 private tel first;
 private tel last;
 private  tel cur ;
    public telList() 
    {
     first = null ;
     last = null ;
    }
    public boolean isEmpty()
    {return first == null; }

    public  tel getCur() {
                return cur;
        }
        public void setCur(tel cur1) {
                cur = cur1;
        }
    public void insert(String na,String addr ,int pho)
    {
    tel newtel = new tel(na,addr,pho);

    if (isEmpty())
    {
     last = newtel;
     first = newtel;
    }

    else
    { 
     newtel.setNext(first);
        first.setPrev(newtel);
      first = newtel;
    }

    }

    //////////////////////////////////
    public tel search(String Key)
    {
     tel cur = first;
     while(cur.getName() != Key)
     {
      if(cur.getNext()== null)
       return null;
      else  
      cur = cur.getNext();   
       }

     return cur; 
    }


    public void displaythelist()
    {
     tel cur = first;
     while(cur != null)
     {
      System.out.println(cur.display());

      cur = cur.getNext();
     }
     System.out.println(" ");
    }

}
//3ed class
//-------------------------------------------------------------------------------------------------------------------
import java.io.*;
import java.util.*;
public class telTest {
public static void main(String[] args)throws Exception {

Scanner input = new Scanner(System.in);
boolean quit = false;
 do { 
         int menu = 0;
       System.out.println("******************************");
         System.out.println("Telephone Directory");
         System.out.println();
         System.out.println("1. Accept Data");
         System.out.println("2. Search");
         System.out.println("3. List of all persons");
         System.out.println("4. Exit");

         System.out.print("Please enter your choice: ");
         menu = input.nextInt();
         System.out.println();
         tel t = new tel();
         telList t1 = new telList();
     switch (menu) {
 case 1:
          System.out.print("Enter Name: ");
          String name = input.next();
          t.setName(name);
          System.out.print("Enter Address: ");
          String address = input.next();
          t.setAddress(address); 
          System.out.print("Enter Phone No: ");
          int no = input.nextInt();
          t.setPhoneNo(no);
          t1. insert(t.getName(),t.getAddress(),t.getPhoneNo());
 break ;
//...........................................................................
 case 2:
       System.out.print("Enter name to search information: ");
         String n = input.next();
     try {
         t1.search(t.getName());

         }

    catch (Exception e) {
                            }

 break;
//...........................................................................   
   case 3://list
         try {
          t1.displaythelist();

          }

    catch (Exception e) {
                            }
    break;
 //...........................................................................
   case 4 ://exit
          quit = true;
   break;
 //........................................................................... 
    default:
         System.out.println("Invalid Entry!");
     }
     }while (!quit);
 }
 }

---

Replace

while(cur.getName() != Key)

with

while(!cur.getName().equals(Key))

You are comparing for object equality with !=. You want to compare the characters of the string instead (two different strings with the same characters should compare as equal).

---

Are you sure they should be Static ??

   private static String name;
   private static String address;
   private static int phoneNo;

I think it should be

private String name;
//... etc.

Edit : Also I think that

telList t1 = new telList();

on main() should be outside the do loop

Edit2 :

on main() when you t1.insert(t.getName(),t.getAddress(),t.getPhoneNo()); on case 1: You don't really use the object you created on main so just do it like that :

        case 1:
            System.out.print("Enter Name: ");
            String name = input.next();
            //t.setName(name);
            System.out.print("Enter Address: ");
            String address = input.next();
            //t.setAddress(address); 
            System.out.print("Enter Phone No: ");
            int no = input.nextInt();
            //t.setPhoneNo(no);
            t1.insert(name,address,no);

From what I see you create a new object anyway in t1

But make sure you put telList t1 = new telList(); OUTSIDE of the do loop because you re-instantiate it every time.