使用 AKKA-HTTP Java 加载静态内容时出错答案

【问题标题】：Error when loading static content using AKKA-HTTP Java使用 AKKA-HTTP Java 加载静态内容时出错
【发布时间】：2018-10-06 18:45:47
【问题描述】：

我第一次在 Java 中尝试 AKKA-Http（akka-http_2.12 v 10.1.5，akka-stream_2.12 v 2.5.17），但似乎无法为招摇加载静态内容用户界面。我已经添加了下面的路由，并且能够通过 http://localhost:8080/api-docs/swagger.json 和 http://localhost:8080/api-docs/swagger.yaml 到达 json 和 yaml swagger 端点但是，swagger UI 端点，即 http://localhost:8080/swagger 返回 'There was an internal server error.' 即使我在 src/main/resources 文件夹下有 swagger-ui 目录。我检查了日志，但不太明白发生了什么......似乎是 getFromResource 和 getFromResourceDirectory 函数中的错误。 Similar issue was reported earlier

Route createRoute() {
        return route(
                path(PathMatchers.segment(generator.apiDocsPath()).slash("swagger.yaml"),
                () -> get(() -> complete(generator.generateSwaggerYaml()))),
                path(PathMatchers.segment(generator.apiDocsPath()).slash("swagger.json"),
                        () -> get(() -> complete(generator.generateSwaggerJson()))),
                path("swagger", () -> route (
                        getFromResource("swagger-ui/index.html"),
                        getFromResourceDirectory("swagger-ui")
                        )
                )
        );
    }

akka-spring-docker-system | 2018-10-06 08:27:11.292 ERROR 9 --- [lt-dispatcher-8] akka.actor.ActorSystemImpl               : Error during processing of request: 'java.lang.NullPointerException (No error message supplied)'. Completing with 500 Internal Server Error response. To change default exception handling behavior, provide a custom ExceptionHandler.
akka-spring-docker-system | 
akka-spring-docker-system | java.lang.NullPointerException: null
akka-spring-docker-system |     at akka.http.scaladsl.server.directives.FileAndResourceDirectives$ResourceFile$.apply(FileAndResourceDirectives.scala:286) ~[akka-http_2.12-10.1.5.jar!/:10.1.5]
akka-spring-docker-system |     at akka.http.scaladsl.server.directives.FileAndResourceDirectives.$anonfun$getFromResource$2(FileAndResourceDirectives.scala:106) ~[akka-http_2.12-10.1.5.jar!/:10.1.5]
akka-spring-docker-system |     at scala.Option.flatMap(Option.scala:171) ~[scala-library-2.12.4.jar!/:na]
akka-spring-docker-system |     at akka.http.scaladsl.server.directives.FileAndResourceDirectives.$anonfun$getFromResource$1(FileAndResourceDirectives.scala:106) ~[akka-http_2.12-10.1.5.jar!/:10.1.5]

【问题讨论】：

标签： java akka swagger akka-stream akka-http

【解决方案1】：

回答我的问题，通过在路径中添加 BOOT-INF 来解决这个问题，如下所示

 return route(
                path(PathMatchers.segment(generator.apiDocsPath()).slash("swagger.yaml"),
                () -> get(() -> complete(generator.generateSwaggerYaml()))),
                path(PathMatchers.segment(generator.apiDocsPath()).slash("swagger.json"),
                        () -> get(() -> complete(generator.generateSwaggerJson()))),
                pathPrefix("swagger", () -> route ( // everything that's inside `/swagger`
                        pathEndOrSingleSlash(() -> getFromResource("BOOT-INF/classes/swagger-ui/index.html")), // `/swagger/` or `/swagger`
                        getFromResourceDirectory("BOOT-INF/classes/swagger-ui") // everything else in `/swagger/...`
                )
        ));

【讨论】：