Building a Chat Application with GRPC in Java and Python

Building a Chat Application with GRPC in Java and Python

Table of Contents

• Introduction
• Architecture of the Chatting Application
• Implementation Details
  • Grpc Server
  • Grpc Client
• Chat Services
  • List
  • Join
  • Leaf
  • Post
  • Help
  • Receive
• Data Structures Used
• Method Descriptions
  • Show Help
  • Add to Channel
  • Check Client Existence
  • List Channels and Clients
  • Join Channel
  • Leave Channel
  • Post Message
• Message Format
• Setting Up and Connecting to the Server

Article

Introduction

The implementation of a chatting application using gRPC server and client provides a seamless experience for users to communicate in real-time. In this project, the gRPC server is created using Java, while the gRPC client is developed in Python. This article will explore the architecture of the chatting application and Delve into the implementation details of the server and client components.

Architecture of the Chatting Application

The chatting application follows a client-server model. The chat server acts as the server, and the chat client serves as the client. When the server starts the connection, the client can join the connection by creating a channel. The application consists of several predefined chat services that implement various remote procedure calls (RPCs). These RPCs include methods such as list, join, leaf, post, help, and receive.

Implementation Details

The implementation of the chat server is done using concurrent hash maps for efficient data structure organization. Each method in the server has a specific functionality. To provide a clear understanding, let's go through some of the key methods.

Chat Services

List

The list method is one of the commands that the user can send to the client. It retrieves a list of available channels and the clients associated with each channel. This information is then sent back to the client using the stream observer.

Join

The join method allows a client to join a specific channel. It takes the channel name and client ID as parameters. Before joining the channel, it checks if the client is already a part of the specified channel. If the client is not in the channel, they are added, and a success message is sent. If the client is already a part of the channel, a message indicating their existing presence is returned.

Leaf

The leaf method is responsible for removing a client from a channel. If a client sends a leave command, they will be removed from the channel.

Post

The post method enables clients to post messages to a channel. It takes the channel name, client ID, nickname, and content of the message as parameters. The method checks if the client exists and provides error messages if needed. If the client is part of the channel, the message is then sent to all the clients in the channel.

Help

The help method displays a list of available commands that the user can utilize to navigate through the program. It returns the available commands to the client.

Receive

The receive method is used as a response to send messages back to the client. Whenever a message is generated, a new chat builder is created, and the message is sent to the client using the on next command. This ensures effective communication between the server and client.

Data Structures Used

To organize the data efficiently, concurrent hash maps are utilized in the implementation of the chat server application. These data structures provide concurrency support and allow for seamless data organization.

Method Descriptions

Show Help

This method provides the user with a list of all the different commands they can use to navigate through the program. It uses the RPC message from the client and sends the response using the stream observer.

Add to Channel

This method is used to add a client to a specific channel. It takes the client's ID, channel name, and a stream observer to send the response. It checks if the client is already in the channel and adds them if they are not. If the client is already part of the channel, a message indicating their presence is sent.

Check Client Existence

The check if client exists method is a Helper method used by other methods such as list channels and list clients. It verifies whether a client exists or not.

List Channels and Clients

The list method allows the user to retrieve a list of available channels and the clients associated with each channel. It takes the message as the command from the user and sends the response back to the client using the stream observer.

Join Channel

The join method enables a client to join a specific channel by providing the channel name and client ID. It checks if the client is already part of the channel and adds them if they are not. If the client is already in the channel, a message indicating their presence is returned.

Leave Channel

The leave method allows a client to leave a channel. If a client sends a leave command, they will be removed from the channel.

Post Message

The post method is used for clients to post messages to a channel. It takes the channel name, client ID, nickname, and message content as parameters. The method checks whether the client exists and provides error messages if necessary. If the client is part of the channel, the message is sent to all clients in the channel.

Message Format

The format of the message sent in the chat program follows a specific structure. The message includes the user's nickname, the message content, the channel name, and the timestamp of when the message was posted.

Setting Up and Connecting to the Server

To set up the server and connect to it, follow these steps:

1. Start the server.
2. The server will display a message stating the server is started on a specific port.
3. Start the clients.
4. When a client is connected to the server, a message will be displayed indicating the successful connection.
5. Use the help method to view all available commands.
6. Set a nickname for the client using the appropriate command.
7. Join a channel using the join command.
8. Post messages to the channel using the post command.
9. To leave the channel, use the leave command.

By following these steps, users can effectively Interact with the chat server application and engage in real-time communication with other clients.

Highlights

• Seamless chatting application implementation using gRPC server and client.
• Architecture Based on the client-server model.
• Key methods include list, join, leaf, post, help, and receive.
• Efficient organization of data using concurrent hash maps.
• Step-by-step guide to setting up and connecting to the server.

FAQ

Q: How is the chatting application structured? A: The chatting application follows a client-server model, where the chat server acts as the server and the chat client serves as the client.

Q: What are some of the key methods in the chat server? A: Some key methods include list, join, leaf, post, help, and receive. These methods enable functionalities such as retrieving a list of available channels, joining channels, posting messages, and more.

Q: How is the data organized in the chat server? A: Concurrent hash maps are used to efficiently organize the data in the chat server. These data structures provide concurrency support and facilitate seamless data organization.

Q: How can users connect to the chat server? A: Users can connect to the chat server by starting the server, starting the clients, and utilizing commands such as join, post, and leave to interact with the server.

Q: What message format is used in the chat program? A: The message format includes the user's nickname, the message content, the channel name, and the timestamp of when the message was posted.