mobilePhone contact code.

Class Contact

package com.company;

public class lectureContact {
    private String name;
    private String phoneNumber;             // field

    //constructor
    public lectureContact(String name, String phoneNumber) {
        this.name = name;
        this.phoneNumber = phoneNumber;
    }

    //getter
    public String getName(){
        return name;
    }
    public String getPhoneNumber(){
        return phoneNumber;
    }

    //another method
    public static lectureContact createContact(String name, String phoneNumber){
        return new lectureContact(name,phoneNumber);
    }
    //that method is just calling constructor nothing else,
    // you don't have to write code 100% as Tim,
    // this is just another way to solve the challenge, there are many ways.
}

Class mobilePhone

package com.company;

import java.util.ArrayList;

public class lectureMobilePhone {           //master class / hold Arraylist

    private String myNumber;                             //field
    private ArrayList<lectureContact> myContacts;       //arrayList define/ class<data type> object
    // data type을 contact class이용

    //constructor
    public lectureMobilePhone(String myNumber) {
        this.myNumber = myNumber;
        this.myContacts = new ArrayList<lectureContact>();  //ArrayList 공간설정
    }

    //method- add, modify, remove, find name, query contact(number), print

    public boolean addNewContact(lectureContact contact){
        if(findContact(contact.getName())>=0){                 //object contact.getName
            System.out.println("contact is already on file");
            return false;
        }
        myContacts.add(contact);
        return true;
    }
    public boolean modifyContact(lectureContact oldContact, lectureContact newContact){
        int foundIndex = findContact(oldContact);
        if(foundIndex<0){
            System.out.println(oldContact.getName()+" was not found");
            return false;                               // modify 안됐으니 false
        } else if(findContact(newContact.getName()) != -1){
            System.out.println("already existing name");    //이름중복되는경우 아웃
            return false;
        }
        this.myContacts.set(foundIndex, newContact);        //ArrayList 해당값 바꾸기(재설정).
        System.out.println(oldContact.getName()+" was replaced with"+newContact.getName());
        return true;
    }

    public boolean removeContact(lectureContact contact){
        int foundIndex = findContact(contact);
        if(foundIndex<0){
            System.out.println(contact.getName()+" was not found");
            return false;
        }
        this.myContacts.remove(foundIndex);        //ArrayList 해당값 삭제
        System.out.println(contact.getName() + " was deleted.");
        return true;
    }

    private int findContact(lectureContact contact){
         return this.myContacts.indexOf(contact);
    }
    private int findContact(String contactName){               //i=index
        for(int i=0; i<this.myContacts.size(); i++){
            lectureContact contact = this.myContacts.get(i);   //class object = array i 값
            if(contact.getName().equals(contactName)){
                return i;
            }
        }
        return -1;
    }
    public String queryContact(lectureContact contact){
        if(findContact(contact)>=0){
            return contact.getName();
        }
        return null;
    }
    public lectureContact queryContact(String name){
        int index = findContact(name);
        if(index>=0){
            return this.myContacts.get(index);
        }
        return null;
    }
    public void printContact(){
        System.out.println("Contact list");
        for(int i=0; i<this.myContacts.size(); i++){
            System.out.println((i+1)+"."+this.myContacts.get(i).getName()+" : "+
                    this.myContacts.get(i).getPhoneNumber());
        }
    }
}
                                                                            

Main. print out

 

package com.company;            //class contact -> class mobile: contact-arrayList로 연결

import java.util.Scanner;

public class lectureMain {
    private static Scanner scanner = new Scanner(System.in);        //console input search
    private static lectureMobilePhone mobilePhone = new lectureMobilePhone("011 2843 2978");   //object. call constructor

    public static void main(String[] args) {
        boolean quit = false;       // boolean defualt는 false
        startPhone();
        Instruction();
        while(!quit){                   // !quit =>   quit=false일때 라는 말임.
            System.out.println("\nEnter action Number");
            int actionNumber = scanner.nextInt();                 //consle input
            scanner.nextLine();

            switch(actionNumber){
                case 0:
                    System.out.println("\nShutting down..");
                    quit = true;
                    break;
                case 1:
                    mobilePhone.printContact();
                    break;
                case 2:
                    addNewContact();
                    break;
                case 3:
                    modifyContact();
                    break;
                case 4:
                    removeContact();
                    break;
                case 5:
                    queryContact();
                    break;
                case 6:
                    Instruction();
                    break;
            }
        }
    }
    //add, modify, remove, query(문의), star ,instruction method
    private static void addNewContact(){
        System.out.println("Enter new contact name: ");
        String name = scanner.nextLine();                   //console string input
        System.out.println("Enter phone number");
        String phone = scanner.nextLine();                  //console string input
        lectureContact newContact = lectureContact.createContact(name, phone); //Contact object
        if(mobilePhone.addNewContact(newContact)){              //mobile object.method(contact object)
            System.out.println("New contact added name = "+name+" phone = "+phone);
        }else{
            System.out.println("already on file");
        }
    }
    private static void modifyContact(){
        System.out.println("Enter current name : ");
        String name =scanner.nextLine() ;
        lectureContact currentName = mobilePhone.queryContact(name);
        if(currentName==null){
            System.out.println("cannot be found");
            return;
        }
        System.out.println("Enter new contact name : ");
        String newName = scanner.nextLine();
        System.out.println("Enter new phone number : ");
        String newPhoneNumber = scanner.nextLine();
        lectureContact newContact = lectureContact.createContact(newName,newPhoneNumber);
        if(mobilePhone.modifyContact(currentName,newContact)){
            System.out.println("modified");
        }else{
            System.out.println("Error modifying record");
        }
    }
    private static void removeContact(){
        System.out.println("Enter current name");
        String name = scanner.nextLine();
        lectureContact currentName = mobilePhone.queryContact(name);
        if(currentName==null){
            System.out.println("contact not found");
            return;
        }
        if(mobilePhone.removeContact(currentName)){
            System.out.println("deleted");
        }else{
            System.out.println("not deleted");
        }
    }
    private static void queryContact(){
        System.out.println("Enter current name : ");
        String name = scanner.nextLine();
        lectureContact currentName = mobilePhone.queryContact(name);
        if(currentName==null){
            System.out.println("contact not found");
            return;
        }
        System.out.println("Name: "+currentName.getName()+"phone number is"+currentName.getPhoneNumber());
    }
    private static void startPhone(){
        System.out.println("Staring phone...");
    }
    private static void Instruction(){
        System.out.println("\n Available action : \n press ");
        System.out.println("0 - to shutdown\n"+
                            "1 - to print contact\n"+
                            "2 - to add contact\n"+
                            "3 - to modify contact\n"+
                            "4 - to remove contact\n"+
                            "5 - to query if contact exist\n"+
                            "6 - to print Instruction\n");
        System.out.println("Choose your action: ");
    }

}

 

Out put

 

D:\IT\JDK\jdk11.0.6_10\bin\java.exe "-javaagent:D:\IT\IDEA\IntelliJ IDEA Community Edition 2020.1\lib\idea_rt.jar=53079:D:\IT\IDEA\IntelliJ IDEA Community Edition 2020.1\bin" -Dfile.encoding=UTF-8 -classpath D:\IT\NewProject\ArrayList\out\production\ArrayList com.company.lectureMain
Staring phone...

 Available action : 
 press 
0 - to shutdown
1 - to print contact
2 - to add contact
3 - to modify contact
4 - to remove contact
5 - to query if contact exist
6 - to print Instruction

Choose your action: 

Enter action Number
1
Contact list

Enter action Number
2
Enter new contact name: 
ag
Enter phone number
01130484
New contact added name = ag phone = 01130484

Enter action Number
2
Enter new contact name: 
ag
Enter phone number
01130484
contact is already on file
already on file

Enter action Number
2
Enter new contact name: 
jina
Enter phone number
35983020
New contact added name = jina phone = 35983020

Enter action Number
4
Enter current name
jina
jina was deleted.
deleted

Enter action Number
5
Enter current name : 
jina
contact not found

Enter action Number
6

 Available action : 
 press 
0 - to shutdown
1 - to print contact
2 - to add contact
3 - to modify contact
4 - to remove contact
5 - to query if contact exist
6 - to print Instruction

Choose your action: 

Enter action Number
0

Shutting down..

Process finished with exit code 0

Out put -  modify에 중복이름 입력경우

D:\IT\JDK\jdk11.0.6_10\bin\java.exe "-javaagent:D:\IT\IDEA\IntelliJ IDEA Community Edition 2020.1\lib\idea_rt.jar=53319:D:\IT\IDEA\IntelliJ IDEA Community Edition 2020.1\bin" -Dfile.encoding=UTF-8 -classpath D:\IT\NewProject\ArrayList\out\production\ArrayList com.company.lectureMain
Staring phone...

 Available action : 
 press 
0 - to shutdown
1 - to print contact
2 - to add contact
3 - to modify contact
4 - to remove contact
5 - to query if contact exist
6 - to print Instruction

Choose your action: 

Enter action Number
2
Enter new contact name: 
john
Enter phone number
1245
New contact added name = john phone = 1245

Enter action Number
2
Enter new contact name: 
pids
Enter phone number
0897
New contact added name = pids phone = 0897

Enter action Number
1
Contact list
1.john : 1245
2.pids : 0897

Enter action Number
3
Enter current name : 
john
Enter new contact name : 
pids
Enter new phone number : 
394
already existing name
Error modifying record

Enter action Number