miniweb

1.新建netcore空项目

2.新建Country.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace MiniWeb
{
    public class Country
    {
        public string CountryCode { get; set; }
        public string CountryName { get; set; }
        public string CurrencyCode { get; set; }
        public string Population { get; set; }
        public string Capital { get; set; }
        public string ContinentName { get; set; }
        public string Continent { get; set; }
        public string AreaInSqKm { get; set; }
        public string Languages { get; set; }
        public string GeonameId { get; set; }
    }
}

3.新建接口及其实现

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace MyMiniWeb
{
   public interface ICountryRepository
    {
        IQueryable<Country> All();
        IQueryable<Country> AllBy(string filter);
        Country Find(string code);
    }
}

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;

namespace MiniWeb
{
    public class CountryRepository : ICountryRepository
    {
        private static IList<Country> _countries;
        public IQueryable<Country> All()
        {
            EnsureCountriesAreLoaded();
            return _countries.AsQueryable();
        }

        public IQueryable<Country> AllBy(string filter)
        {
            return string.IsNullOrEmpty(filter)
                ? All()
                : All().Where(m => m.CountryName.ToLower().StartsWith(filter.ToLower()));

        }

        public Country Find(string code)
        {
            return All().Where(c => c.CountryCode.Equals(code, StringComparison.CurrentCultureIgnoreCase)).FirstOrDefault();
        }

        private static void EnsureCountriesAreLoaded()
        {
            if (_countries == null)
                _countries = LoadCountriesFromStream();
        }

        private static IList<Country> LoadCountriesFromStream()
        {
            var json = File.ReadAllText("Countries.json");
            var contries = JsonConvert.DeserializeObject<Country[]>(json);
            return contries;
        }
    }
}

 3.新建Countries.json

[
	{
		"countryCode": "AD",
		"countryName": "Andorra",
		"currencyCode": "EUR",
		"population": "84000",
		"capital": "Andorra la Vella",
		"continentName": "Europe",
		"continent": "EU",
		"areaInSqKm": "468.0",
		"languages": "ca",
		"geonameId": "3041565"
	},
	{
		"countryCode": "AE",
		"countryName": "United Arab Emirates",
		"currencyCode": "AED",
		"population": "4975593",
		"capital": "Abu Dhabi",
		"continentName": "Asia",
		"continent": "AS",
		"areaInSqKm": "82880.0",
		"languages": "ar-AE,fa,en,hi,ur",
		"geonameId": "290557"
	},
	{
		"countryCode": "AF",
		"countryName": "Afghanistan",
		"currencyCode": "AFN",
		"population": "29121286",
		"capital": "Kabul",
		"continentName": "Asia",
		"continent": "AS",
		"areaInSqKm": "647500.0",
		"languages": "fa-AF,ps,uz-AF,tk",
		"geonameId": "1149361"
	},
	{
		"countryCode": "AG",
		"countryName": "Antigua and Barbuda",
		"currencyCode": "XCD",
		"population": "86754",
		"capital": "St. John's",
		"continentName": "North America",
		"continent": "NA",
		"areaInSqKm": "443.0",
		"languages": "en-AG",
		"geonameId": "3576396"
	}
]

4.注册服务

   public void ConfigureServices(IServiceCollection services)
        {
            services.AddSingleton<ICountryRepository>(new CountryRepository());
        }

5. 配置应用程序

 public void Configure(IApplicationBuilder app, IWebHostEnvironment env,ICountryRepository country)
        {
            
            app.Run(async (context) =>
            {
                var query = context.Request.Query["q"];
                var listOfCountries = country.AllBy(query).ToList();
                var json = JsonConvert.SerializeObject(listOfCountries);
                await context.Response.WriteAsync(json);
            });
        }