asp.net – 覆盖webapi odata链接的主机

我正在使用WebAPI 2.2和Microsoft.AspNet.OData 5.7.0来创建支持分页的OData服务.

当在生产环境中托管时,WebAPI存在于外部未公开的服务器上,因此OData响应中返回的各种链接(例如@ odata.context和@ odata.nextLink)指向内部IP地址,例如,http：//192.168.X.X/\u0026lt; AccountName> / api / …等

我已经能够修改Request.ODataProperties().NextLink,在每个ODataController方法中实现一些逻辑,用一个外部URL替换内部URL,如https://account-name.domain.com/api/. ..,但这非常不方便,只能修复NextLinks.

有没有办法在OData服务的配置时设置外部主机名？我已经看到了一个属性Request.ODataProperties().路径并想知道是否可以在config.MapODataServiceRoute(“odata”,“odata”,GetModel())中设置基本路径;调用,或在GetModel()实现中使用例如ODataConventionModelBuilder？

更新：到目前为止我提出的最佳解决方案是创建一个BaSEODataController来覆盖Initialize方法并检查Request.RequestUri.Host.StartsWith(“begin-of-internal-IP-address”)然后执行RequestUri重写,如下所示：

var externalAddress = ConfigClient.Get().ExternalAddress;  // e.g. https://account-name.domain.com
var account = ConfigClient.Get().Id;  // e.g. AccountName
var uriToReplace = new Uri(new Uri("http://" + Request.RequestUri.Host),account);
string originalUri = Request.RequestUri.AbsoluteUri;
Request.RequestUri = new Uri(Request.RequestUri.AbsoluteUri.Replace(uriToReplace.AbsoluteUri,externalAddress));
string newUri = Request.RequestUri.AbsoluteUri;
this.GetLogger().Info($"Request URI was rewritten from {originalUri} to {newUri}");

这完美地修复了所有控制器的@ odata.nextLink URL,但由于某种原因,@ odata.context URL仍然获得AccountName部分(例如https://account-name.domain.com/AccountName/api/odata/ $Metadata#ControllerName),因此它们仍然不起作用.

解决方法

重写RequestUri足以影响@ odata.nextLink值,因为 code that computes the next link直接依赖于RequestUri.其他@ odata.xxx链接是通过 UrlHelper计算的,它以某种方式引用原始请求URI的路径. (因此你在@ odata.context链接中看到的AccountName.我在我的代码中看到过这种行为,但是我无法找到缓存的URI路径的来源.)

我们可以通过创建CustomUrlHelper类来动态重写OData链接,而不是重写RequestUri.新的GetNextPageLink方法将处理@ odata.nextLink重写,而Link方法覆盖将处理所有其他重写.

public class CustomUrlHelper : System.Web.Http.Routing.UrlHelper
{
    public CustomUrlHelper(HttpRequestMessage request) : base(request)
    { }

    // Change these strings to suit your specific needs.
    private static readonly string ODaTarouteName = "ODaTaroute"; // Must be the same as used in api config
    private static readonly string TargetPrefix = "http://localhost:8080/somePathPrefix"; 
    private static readonly int TargetPrefixLength = TargetPrefix.Length;
    private static readonly string ReplacementPrefix = "http://www.contoso.com"; // Do not end with slash

    // Helper method.
    protected string ReplaceTargetPrefix(string link)
    {
        if (link.StartsWith(TargetPrefix))
        {
            if (link.Length == TargetPrefixLength)
            {
                link = ReplacementPrefix;
            }
            else if (link[TargetPrefixLength] == '/')
            {
                link = ReplacementPrefix + link.Substring(TargetPrefixLength);
            }
        }

        return link;
    }

    public override string Link(string routeName,IDictionary<string,object> routeValues)
    {
        var link = base.Link(routeName,routeValues);

        if (routeName == ODaTarouteName)
        {
            link = this.ReplaceTargetPrefix(link);
        }

        return link;
    }

    public Uri GetNextPageLink(int pageSize)
    {
        return new Uri(this.ReplaceTargetPrefix(this.Request.GetNextPageLink(pageSize).ToString()));
    }
}

在基本控制器类的Initialize方法中连接CustomUrlHelper.

public abstract class BaSEODataController : ODataController
{
    protected abstract int DefaultPageSize { get; }

    protected override void Initialize(System.Web.Http.Controllers.HttpControllerContext controllerContext)
    {
        base.Initialize(controllerContext);

        var helper = new CustomUrlHelper(controllerContext.Request);
        controllerContext.RequestContext.Url = helper;
        controllerContext.Request.ODataProperties().NextLink = helper.GetNextPageLink(this.DefaultPageSize);
    }

请注意,在给定的控制器类中,页面大小对于所有操作都是相同的.您可以通过将ODataProperties().NextLink的赋值移动到特定操作方法的主体来解决此限制,如下所示：

var helper = this.RequestContext.Url as CustomUrlHelper;
this.Request.ODataProperties().NextLink = helper.GetNextPageLink(otherPageSize);