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API / @angular/common/http

HttpInterceptor

Intercepts HttpRequest and handles them.

拦截 HttpRequest 并处理它们。

interface HttpInterceptor { intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> }

说明

Most interceptors will transform the outgoing request before passing it to the next interceptor in the chain, by calling next.handle(transformedReq).

大多数拦截器都会在外发的请求由 next.handle(transformedReq) 发给拦截器链中的下一个拦截器之前，对该请求进行转换。

In rare cases, interceptors may wish to completely handle a request themselves, and not delegate to the remainder of the chain. This behavior is allowed.

极少量情况下，拦截器也可能希望自己完全处理一个请求，而不再委托给拦截器链中的其它部分。这种行为也是允许的。

方法

intercept()

Intercept an outgoing HttpRequest and optionally transform it or the response.

拦截外发的 HttpRequest，并（可选的）转换它或转换响应对象。

intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>>

参数

req

Type: HttpRequest.

next

Type: HttpHandler.

返回值

Observable<HttpEvent<any>>

Typically an interceptor will transform the outgoing request before returning next.handle(transformedReq). An interceptor may choose to transform the response event stream as well, by applying additional Rx operators on the stream returned by next.handle().

通常，拦截器将会在返回 next.handle(transformedReq) 之前转换外发请求。 选择器也可以选择通过在 next.handle() 返回的流上应用 Rx 操作符（operator）来转换响应事件流。

More rarely, an interceptor may choose to completely handle the request itself, and compose a new event stream instead of invoking next.handle(). This is acceptable behavior, but keep in mind further interceptors will be skipped entirely.

更罕见的情况下，拦截器可以选择完全由自己处理该请求，并合成新的事件流而不是调用 next.handle()。 这种方式也是可以接受的，不过要记住这样做会完全忽略所有的后续拦截器。

It is also rare but valid for an interceptor to return multiple responses on the event stream for a single request.

另一种同样罕见但是有用的拦截器，会为单个请求在事件流上给出多个响应对象。