URL shortening

Question

Hi. i want to shorten my URL and after shortening it should be clickable in asp.net Any way i can do that ? For ex. example_com is my original url, i am expecting url to abcd Thanks in advance !!!

Prasad Raveendran · Answer

Here's a step-by-step guide with a sample implementation. Step 1: Create a new .NET Core Web API Project Open Visual Studio or your preferred code editor and create a new .NET Core Web API project. Step 2: Install Required Packages You'll need the Entity Framework Core package to work with a database and a package for generating random strings. Install these packages using NuGet Package Manager or the .NET CLI: dotnet add package Microsoft.EntityFrameworkCore.SqlServer dotnet add package Microsoft.EntityFrameworkCore.Design dotnet add package System.Data.SqlClient dotnet add package System.Data.Common dotnet add package System.Data.Common.Safety dotnet add package System.Data.SqlClient.Safety Step 3: Create a Model Create a model to represent the URL mappings. In this example, we'll use Entity Framework Core for data access. // Models/UrlMapping.cs using System.ComponentModel.DataAnnotations; public class UrlMapping { [Key] public int Id { get; set; } [Required] public string LongUrl { get; set; } [Required] public string ShortUrl { get; set; } } Step 4: Set up the Database Context Create a database context class to manage the URL mappings in the database. // Data/UrlShorteningContext.cs using Microsoft.EntityFrameworkCore; public class UrlShorteningContext : DbContext { public UrlShorteningContext(DbContextOptions options) : base(options) { } public DbSet UrlMappings { get; set; } } Step 5: Configure Database Connection In your appsettings.json or appsettings.Development.json file, add the connection string for your database: { "ConnectionStrings": { "DefaultConnection": "your_connection_string_here" }, // ... } Step 6: Configure Entity Framework In the Startup.cs file, configure Entity Framework to use the database connection. // Startup.cs using Microsoft.EntityFrameworkCore; using Microsoft.Extensions.Configuration; // ... public void ConfigureServices(IServiceCollection services) { // ... services.AddDbContext (options => options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection"))); // ... } Step 7: Create Shortening Logic Now, create a service that handles URL shortening logic. Here's a simple implementation using random string generation: // Services/UrlShorteningService.cs using System; using System.Linq; using Microsoft.EntityFrameworkCore; public class UrlShorteningService { private readonly UrlShorteningContext _context; private const string Characters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; private const int ShortUrlLength = 6; public UrlShorteningService(UrlShorteningContext context) { _context = context; } public string ShortenUrl(string longUrl) { var existingMapping = _context.UrlMappings.FirstOrDefault(x => x.LongUrl == longUrl); if (existingMapping != null) { return existingMapping.ShortUrl; } var random = new Random(); var shortUrl = new string(Enumerable.Repeat(Characters, ShortUrlLength) .Select(s => s[random.Next(s.Length)]).ToArray()); _context.UrlMappings.Add(new UrlMapping { LongUrl = longUrl, ShortUrl = shortUrl }); _context.SaveChanges(); return shortUrl; } public string GetLongUrl(string shortUrl) { var mapping = _context.UrlMappings.FirstOrDefault(x => x.ShortUrl == shortUrl); return mapping?.LongUrl; } } Step 8: Create API Controllers Create API controllers to expose the URL shortening functionality. // Controllers/UrlShorteningController.cs using Microsoft.AspNetCore.Mvc; [Route("api/[controller]")] [ApiController] public class UrlShorteningController : ControllerBase { private readonly UrlShorteningService _urlShorteningService; public UrlShorteningController(UrlShorteningService urlShorteningService) { _urlShorteningService = urlShorteningService; } [HttpPost("shorten")] public IActionResult ShortenUrl([FromBody] string longUrl) { var shortUrl = _urlShorteningService.ShortenUrl(longUrl); return Ok(shortUrl); } [HttpGet("expand/{shortUrl}")] public IActionResult ExpandUrl(string shortUrl) { var longUrl = _urlShorteningService.GetLongUrl(shortUrl); if (longUrl == null) { return NotFound(); } return Ok(longUrl); } } Step 9: Run Migrations and Start the Application Run the following commands to create and apply migrations: dotnet ef migrations add InitialCreate dotnet ef database update Finally, run your .NET Core application: dotnet run Your URL shortening service should now be up and running, exposing two endpoints: /api/urlshortening/shorten for shortening URLs and /api/urlshortening/expand/{shortUrl} for expanding short URLs into their original form. You can test the API using a tool like Postman or curl. Remember that this is a simple example, and you may want to add more features and error handling to make it production-ready. Additionally, consider securing your API and validating URLs before shortening them.

Sachin Singh · Answer

Test this public class UrlShortener { private static final String ALPHABET = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; private static final int BASE = ALPHABET.length(); public static String encode(int num) { StringBuilder sb = new StringBuilder(); while ( num > 0 ) { sb.append( ALPHABET.charAt( num % BASE ) ); num /= BASE; } return sb.reverse().toString(); } public static int decode(String str) { int num = 0; for ( int i = 0; i There are multiple url shortner nugets also available