【ASP.NET Core学习】Web API

时间 2019-12-09

原文原文链接

这里介绍在ASP.NET Core中使用Web API建立 RESTful 服务，本文使用VSCode + NET Core3.0html

建立简单Rest API前端

在终端输入git

dotnet new webapi -n WebAPI

1. 建立Order模型，而后初始化数据github

public class OrderStore
{
    public List<Order> Orders { get; } = new List<Order>();

    public OrderStore()
    {
        var random = new Random();
        foreach (var item in Enumerable.Range(1, 10))
        {
            Orders.Add(new Order
            {
                Id = item,
                OrderNo = DateTime.Now.AddSeconds(random.Next(100, 200)).AddMilliseconds(random.Next(20, 50)).Ticks.ToString(),
                Quantity = random.Next(1, 10),
                Amount = Math.Round(((decimal)random.Next(100, 500) / random.Next(2, 6)), 2)
            });
        }
    }
}

View Code

2. 简单REST API接口web

/// <summary>
/// 订单模块
/// </summary>
[ApiController]
[Route("[controller]")]
[FormatFilter]
public class OrderController : ControllerBase
{

    readonly Models.OrderStore _orderStore = null;
    public OrderController(Models.OrderStore orderStore)
    {
        _orderStore = orderStore;
    }

    /// <summary>
    /// 查询全部订单
    /// </summary>
    [HttpGet]
    public ActionResult<List<Models.Order>> GetAll() => _orderStore.Orders;

    /// <summary>
    /// 获取订单    
    /// </summary>
    /// <param name="id"></param>
    /// <returns></returns>
    [HttpGet("{id:int}.{format?}")]
    public ActionResult<Models.Order> GetById(int id)
    {
        var order = _orderStore.Orders.FirstOrDefault(m => m.Id == id);

        if (order == null)
        {
            return NotFound();
        }

        return order;
    }

    /// <summary>
    /// 建立订单
    /// </summary>
    /// <param name="order"></param>
    /// <returns>成功返回订单Id，失败返回-1</returns>
    [HttpPost]
    public ActionResult<int> Create(Models.Order order)
    {
        if (_orderStore.Orders.Any(m => m.OrderNo == order.OrderNo))
        {
            return -1;
        }

        order.Id = _orderStore.Orders.Max(m => m.Id) + 1;
        _orderStore.Orders.Add(order);

        return order.Id;
    }

    /// <summary>
    /// 更新订单
    /// </summary>
    /// <returns></returns>
    [HttpPut]
    public ActionResult<bool> Update(Models.Order model)
    {
        Console.WriteLine($"OrderNo:{model.OrderNo}");
        var order = _orderStore.Orders.FirstOrDefault(m => m.OrderNo == model.OrderNo);

        if (order == null)
        {
            return NotFound();
        }

        order.Amount = model.Amount;
        order.Quantity = model.Quantity;

        return true;
    }

    /// <summary>
    /// 更新订单指定信息
    /// </summary>
    /// <remarks>
    /// Sample request:
    /// 
    ///     PATCH  /Order/{orderNo} 
    ///     [
    ///         {
    ///             "op": "test",
    ///             "path": "/quantity",
    ///             "value": "2"
    ///         },
    ///         {
    ///             "op": "test",
    ///             "path": "/amount",
    ///             "value": "38.28"
    ///         },
    ///         {
    ///             "op": "add",
    ///             "path": "/isComplete",
    ///             "value": "true"
    ///         },
    ///     ]
    /// </remarks>
    /// <returns>返回是否成功</returns>
    /// <response code="200">提交成功</response>
    /// <response code="400">提交参数异常</response>    
    /// <response code="404">订单号不存在</response>
    [HttpPatch("{orderNo:length(18)}")]
    [ProducesResponseType(StatusCodes.Status200OK)]
    [ProducesResponseType(StatusCodes.Status404NotFound)]
    [ProducesResponseType(StatusCodes.Status400BadRequest)]
    public ActionResult<bool> Update([FromBody] JsonPatchDocument<Models.Order> patchDoc, [FromRoute] string orderNo)
    {
        var order = _orderStore.Orders.FirstOrDefault(m => m.OrderNo == orderNo);

        if (order == null)
        {
            return NotFound();
        }

        patchDoc.ApplyTo(order, ModelState);

        if (!ModelState.IsValid)
        {
            return BadRequest(ModelState);
        }

        return Ok(true);
    }
}

View Code

3. 推荐一个VS Code插件（REST Client）测试接口，官方介绍json

@baseUrl = https://localhost:5001

###
GET {{baseUrl}}/Order HTTP/1.1

### 
# @name order
POST {{baseUrl}}/Order HTTP/1.1
Accept: application/json
Content-Type: application/json

{
    "OrderNo": "637109312996909246",
    "Quantity": 2,
    "Amount": 38.28
}

### 

@orderId = {{order.response.body.*}}
GET {{baseUrl}}/Order/{{orderId}}.json HTTP/1.1

### 
GET {{baseUrl}}/Order/{{orderId}}.xml HTTP/1.1
###
GET {{baseUrl}}/Order/{{orderId}} HTTP/1.1
###

PUT {{baseUrl}}/Order HTTP/1.1
Content-Type: application/json
Accept: application/json

{
    "Id": 12,
    "OrderNo": "2019112235759329",
    "Quantity": 2,
    "Amount": 38.28
}

###

GET {{baseUrl}}/Order/11

###

PATCH  {{baseUrl}}/Order/637109312996909246 HTTP/1.1
Accept: application/json
Content-Type: application/json

[
  {
    "op": "test",
    "path": "/quantity",
    "value": "2"
  },
  {
    "op": "test",
    "path": "/amount",
    "value": "38.28"
  },
  {
    "op": "add",
    "path": "/isComplete",
    "value": "true"
  },
]




Sample request:

PATCH  /Order/{orderNo} 

[
  {
    "op": "test",
    "path": "/quantity",
    "value": "2"
  },
  {
    "op": "test",
    "path": "/amount",
    "value": "38.28"
  },
  {
    "op": "add",
    "path": "/isComplete",
    "value": "true"
  },
]

View Code

简单介绍一下，api

文件后缀是http 或 rest浏览器

定义全局变量：@baseUrl = https://localhost:5001 ，注意连接不加引号app

### 分割多个请求dom

POST/PUT 请求紧跟Head请求信息，换行加上请求内容

Ctrl + Alt + R 快捷键 / 点Send Request发起请求

格式化输出

Api接口一般会是不一样客户端调用，这样会有可能出现须要不一样响应格式，例如经常使用的Json，XML。

ASPNET Core 默认状况下是忽略 Accept 标头，JSON格式返回

1、支持XML格式

1. 添加xml格式化

services.AddControllers(options =>
    {
        options.RespectBrowserAcceptHeader = true;  //接受浏览器标头
    })
    .AddXmlSerializerFormatters();                   //添加XMl格式化
}

2. 请求是添加标头

@orderId = {{order.response.body.*}}
GET {{baseUrl}}/Order/{{orderId}} HTTP/1.1
Accept: text/xml

若不添加标头，默认使用JSON格式输出

2、URL格式映射

1. 添加[FormatFilter]过滤器，它会检查路由中格式是否存在，而且使用相应的格式化程序输出

2. 路由规则添加{format?}

[HttpGet("{id:int}.{format?}")]
public ActionResult<Models.Order> GetById(int id)
{
    var order = _orderStore.Orders.FirstOrDefault(m => m.Id == id);

    if (order == null)
    {
        return NotFound();
    }

    return order;
}

View Code

Url	响应
GET {{baseUrl}}/Order/{{orderId}} HTTP/1.1	JSON(若配置格式化输出）
GET {{baseUrl}}/Order/{{orderId}}.xml	XML(若配置格式化输出）
GET {{baseUrl}}/Order/{{orderId}}.json	JSON(若配置格式化输出）

3、添加基于 Newtonsoft.Json 的 JSON 格式支持

在ASPNET Core 3.0开始，再也不使用Newtonsoft.Json格式化JSON，而是使用System.Text.Json格式化，咱们能够替换成Newtonsoft.Json

1. 添加包

dotnet add package Microsoft.AspNetCore.Mvc.NewtonsoftJson

2. 配置Newtonsoft.Json

public void ConfigureServices(IServiceCollection services)
{
    services.AddControllers()
        .AddNewtonsoftJson(options =>                   //添加基于NewtonsoftJson格式化
        {
            options.SerializerSettings.DateFormatHandling = Newtonsoft.Json.DateFormatHandling.MicrosoftDateFormat;
            options.SerializerSettings.DateFormatString = "yyyy-MM-dd HH:mm:ss";
            options.SerializerSettings.NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore;
        });
}

JSON Patch请求

PUT 和 PATCH 方法用于更新现有资源。它们之间的区别是，PUT 会替换整个资源，而PATCH 仅指定更改。

什么是JSON Patch?

JSON Patch官网里面有一句介绍的很清楚：JSON Patch is a format for describing changes to a JSON document. （一种描述Json的变化的格式）

何时须要用到JSON Patch

咱们返回的JSON很大，修改可能只是某些字段
对性能要求比较大的地方
一个大的对象，好几个地方修改，而后统一接口修改

ASPNET Core如何处理JSON Patch 请求

1. 添加包支持

dotnet add package Microsoft.AspNetCore.JsonPatch

2. 使用 HttpPatch 属性进行批注

3. 接受 JsonPatchDocument<T>，一般带有 [FromBody]

4. 调用 ApplyTo 以应用更改

假设咱们如今有一个完成订单的需求

检查金额，数量是否有变动
更新IsComplete = true

下面附上代码和提交的JSON

控制器代码

[HttpPatch("{orderNo:length(18)}")]
[ProducesResponseType(StatusCodes.Status200OK)]
[ProducesResponseType(StatusCodes.Status404NotFound)]
[ProducesResponseType(StatusCodes.Status400BadRequest)]
public ActionResult<bool> Update([FromBody] JsonPatchDocument<Models.Order> patchDoc, [FromRoute] string orderNo)
{
    var order = _orderStore.Orders.FirstOrDefault(m => m.OrderNo == orderNo);

    if (order == null)
    {
        return NotFound();
    }

    patchDoc.ApplyTo(order, ModelState);

    if (!ModelState.IsValid)
    {
        return BadRequest(ModelState);
    }

    return Ok(true);
}

View Code

失败的JSON（金额校验不过）

PATCH  {{baseUrl}}/Order/637109312996909246 HTTP/1.1
Accept: application/json
Content-Type: application/json

[
  {
    "op": "test",
    "path": "/quantity",
    "value": "2"
  },
  {
    "op": "test",
    "path": "/amount",
    "value": "38.28"
  },
  {
    "op": "add",
    "path": "/isComplete",
    "value": "true"
  },
]

View Code

会在ModelState里面列出校验不过的信息

成功的JSON

PATCH  {{baseUrl}}/Order/637109312996909246 HTTP/1.1
Accept: application/json
Content-Type: application/json

[
  {
    "op": "test",
    "path": "/quantity",
    "value": "2"
  },
  {
    "op": "test",
    "path": "/amount",
    "value": "36.8"
  },
  {
    "op": "add",
    "path": "/isComplete",
    "value": "true"
  },
]

View Code

咱们用Get请求从新查一下，能够看到IsComplete成功被修改了

这里只是简单介绍JSON Patch使用，更多使用方法参考JSON Pan官网和微软文档

Open API（Swagger）集成

Api 一般须要跟客户端，前端进行沟通，须要编写文档，这须要花费大量时间。

Open Api是专门解决这种问题，它为RESTful api定义了一个标准的、与语言无关的接口，利用工具生成文档，能够作到代码即文档(逼着开发者完善注释)

ASPNET Core 可使用Swashbuckle.AspNetCore或NSwag 生成Swagger 文档

下面介绍如何使用Swashbuckle.AspNetCore

1、使用Swashbuckle.AspNetCore

安装Swashbuckle.AspNetCore包

dotnet add package Swashbuckle.AspNetCore

添加并配置 Swagger 中间件

引用命名空间：using Microsoft.OpenApi.Models;

services.AddSingleton<Models.OrderStore>();
                        
services.AddSwaggerGen(c =>
{
    c.SwaggerDoc("v1", new OpenApiInfo { Title = "Web Api Doc", Version = "v1" });
});

app.UseSwagger();
                                
app.UseSwaggerUI(c =>
{
　　c.SwaggerEndpoint("/swagger/v1/swagger.json", "My API V1");
});

　　　　通过上面两步就可使用SwaggerUI来查看文档和测试，浏览器打开（http://{url}/swagger）

2、添加XML注释

上面生成的Swagger文档是不包含XML注释，下面介绍如何添加XML注释

项目文件（*.csproj）添加如下

<PropertyGroup>

<GenerateDocumentationFile>true</GenerateDocumentationFile>

<NoWarn>$(NoWarn);1591</NoWarn>

</PropertyGroup>

加上上面生成文档后，未注释的函数，属性会发出警告，警告代码1591，忽略警告能够添加多个，分号分割

AddSwaggerGen添加下面XML支持

services.AddSwaggerGen(c =>
{
    c.SwaggerDoc("v1", new OpenApiInfo { Title = "Web Api Doc", Version = "v1" });

    var xmlFile = $"{Assembly.GetExecutingAssembly().GetName().Name}.xml";
    var xmlPath = Path.Combine(AppContext.BaseDirectory, xmlFile);
    c.IncludeXmlComments(xmlPath);
});

方法添加注释

/// <summary>
/// 更新订单指定信息
/// </summary>
/// <remarks>
/// Sample request:
/// 
///     PATCH  /Order/{orderNo} 
///     [
///         {
///             "op": "test",
///             "path": "/quantity",
///             "value": "2"
///         },
///         {
///             "op": "test",
///             "path": "/amount",
///             "value": "38.28"
///         },
///         {
///             "op": "add",
///             "path": "/isComplete",
///             "value": "true"
///         },
///     ]
/// </remarks>
/// <returns>返回是否成功</returns>
/// <response code="200">提交成功</response>
/// <response code="400">提交参数异常</response>    
/// <response code="404">订单号不存在</response>

View Code

ProducesResponseType 描述返回类型

remarks 会生成请求说明

效果

Web Api 使用就介绍这些，若有错漏，但愿指出。

转发请标明出处：https://www.cnblogs.com/WilsonPan/p/11945856.html

示例代码：https://github.com/WilsonPan/AspNetCoreExamples/tree/master/WebApi

【ASP.NET Core学习】Web API

安装Swashbuckle.AspNetCore包

添加并配置 Swagger 中间件

项目文件（*.csproj）添加如下

AddSwaggerGen添加下面XML支持

方法添加注释

效果