play for scala 实现SessionFilter 过滤未登录用户跳转到登录页面

Posted 2020-08-20 唐际忠

一、编写SessionFilter.scala代码

package filters
import javax.inject.{Inject, Singleton}
import akka.stream.Materializer
import controllers.routes
import play.api.mvc.{Filter, RequestHeader, Result, Results}
import scala.concurrent.Future
@Singleton
class SessionFilter @Inject()(implicit val mat: Materializer) extends Filter {
  def apply(nextFilter: RequestHeader => Future[Result])
           (requestHeader: RequestHeader): Future[Result] = {
    if (!requestHeader.session.get("user").isDefined && !requestHeader.path.contains("/signin") && !requestHeader.path.contains("/assets/")) {
      Future.successful(Results.Redirect(routes.SignController.showSignin()))
    } else {
      nextFilter(requestHeader)
    }
  }
}

说明：

!requestHeader.session.get("user").isDefined 是用来判断session中是否存在user

!requestHeader.path.contains("/signin") 是用来排除登录页面，这个页面不登录也应该是可见的，防止出现死循环跳转

!requestHeader.path.contains("/assets/") 是用来排除静态资源文件的，如图片、css、javascript等

 

二、在app目录下的Filters.scala中使用SessionFilter

Filters.scala这个文件是activator自动生成的模板，要使用SessionFilter只要在里面加上sessionFilter: SessionFilter和Seq(sessionFilter)就可以了

import javax.inject._
import filters.{ExampleFilter, SessionFilter}
import play.api._
import play.api.http.HttpFilters
import play.api.mvc._
/**
 * This class configures filters that run on every request. This
 * class is queried by Play to get a list of filters.
 *
 * Play will automatically use filters from any class called
 * `Filters` that is placed the root package. You can load filters
 * from a different class by adding a `play.http.filters` setting to
 * the `application.conf` configuration file.
 *
 * @param env Basic environment settings for the current application.
 * @param exampleFilter A demonstration filter that adds a header to
 * each response.
 */
@Singleton
class Filters @Inject() (
  env: Environment,
  exampleFilter: ExampleFilter, sessionFilter: SessionFilter) extends HttpFilters {
  override val filters = {
    // Use the example filter if we‘re running development mode. If
    // we‘re running in production or test mode then don‘t use any
    // filters at all.
    if (env.mode == Mode.Dev) Seq(exampleFilter) else Seq.empty
    Seq(sessionFilter)
  }
}