aminosbh / socialnetwork

Social Network Java Project

The Social Network Java Project is a training project that aims to help students improve their Java programming skills and learn new programming concepts and techniques.

This tutorial is divided into chapters. Each one of them will implement a part of the project and let you learn a unique programming technique.

This tutorial is managed with Git which means that you can go through the different commits to lean about the different steps and development decisions. Each commit is self-documented.

Chapter 0: Create a Maven project

This project uses Maven as a build system and Eclipse as a main IDE.

Create a new Maven project

The following is a list of instructions that let you create a new Maven project using Eclipse:

• Click File > New > Project...
• In the New Project wizard:
  1. Click Maven > Maven Project. Click Next.
  2. In the New Maven Project window, check Create a simple project (...) and the click Next.
  3. Specify the groupId in the Group Id field.

     The groupId uniquely identifies your project across all projects. A group ID should follow Java's package name rules. This means it starts with a reversed domain name you control. For example, org.apache.maven, org.apache.commons

     For more details, see Maven naming conventions

  4. Specify the artifactId in the Artifact Id field.

     The artifactId is the name of the jar without version. If you created it, then you can choose whatever name you want with lowercase letters and no strange symbols. If it's a third party jar, you have to take the name of the jar as it's distributed. eg. maven, commons-math

     For more details, see Maven naming conventions

  5. Keep the default version name and click Finish.

Import the current project

The best way to import this Git project into Eclipse is to import it first as a General Git Project and then convert it to Maven Project:

Import as a General Git Project:

• Click File > Import...
• In the Import wizard:
  1. Click Git > Projects from Git. Click Next.
  2. Click Clone URI and then click Next.
  3. In the Source Git Repository window, in the URI field, enter an existing Git repository URL and click Next.
  4. In the Branch Selection window, make sure that the master branch is selected and click Next.
  5. In the Local Destination window, specify the destination directory or keep the default value and then click Next.
     The Cloning from <Git repository> window shows the progress of the cloning process.
  6. In the menu Wizard of project import, select Import as general project. Click Next.
  7. In the Import Projects window, confirm or edit the default parameters and click Finish.

Convert into Maven Project:

1. In the projects tree, right click on the imported project.
2. Scroll down and click Configure > Convert to Maven Project.

Chapter 1: Contacts management module

In this chapter, we are going to implement the Contacts management module.
We'll start by declaring the different necessary entities (classes, interfaces, enumerations). This list will be enriched with further entities while developing the other modules of this project.

Coding style:

The implementation of our project should follows the Google Coding Style. We can also find some details about that coding style in a document written by Twitter as part of its Java common libraries

Best practices:

• Choosing the right collections
• Always using interface type when declaring a collection.
• Use generic type and diamond operator
• Specify initial capacity of a collection if possible
• Prefer isEmpty() over size()
• Do not use the classic for loop
• etc

For more details about Collections and Generics Best Practices

Contacts management module Entities

class User implements ContactItem:
    login
    password
    firstName
    lastName
    dateOfBirth: Date
    gender: Gender
    photos: List<Photo>
    locations: List<Location>
    emails: List<Email>
    phoneNumbers: List<PhoneNumber>
    contacts: List<ContactItem>

enum Gender:
    MALE, FEMALE

class Photo:
    uri: URI
    title

class Location:
    country
    address
    label

class Email:
    address
    label

class PhoneNumber:
    countryCallingCode: int
    number: long
    label

interface ContactItem

class Group implements ContactItem:
    name
    description
    contacts: List<ContactItem>

MVC pattern

It's a good practice to follow the MVC design pattern, so it's better that we move the different entities in a dedicated package entities .
You can find a basic implement of the MVC design pattern here: https://www.geeksforgeeks.org/mvc-design-pattern

Repository pattern:

The repository pattern abstracts the data store and enables your business logic to define read and write operations on a logical level.
So we'll dedicated a repositories package to contain all repository classes.

Singleton pattern:

The singleton design pattern restricts the instantiation of a class to one "single" instance. This is useful when exactly one unique object is needed across the whole system.
You can find more details and an example of the implementation of the singleton design pattern here: https://www.geeksforgeeks.org/singleton-class-java .
This pattern will be useful for the repository classes. Let's start by the UserRepository class.

License

This project is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0). See COPYRIGHT, LICENSE-APACHE, LICENSE-MIT, DOC-LICENSE, AUTHORS and CONTRIBUTORS for more details.