Play Framework - 尝试映射Promise时无法解析ExecutionContext

Question

WS.url("https://api.humanapi.co/v1/human"+url+"?updated_since="+updatedSince).setHeader("Authorization", "Bearer "+accessToken)
        .setHeader("Accept", "application/json").get().map(
                new Function<WSResponse, JsonNode>() {
                    public JsonNode apply(WSResponse response) {
                        JsonNode json = response.asJson();
                        success(json);
                        return json;
                    }
                }   
    ); 

这会显示错误"无法解析类型scala.concurrent.ExecutionContext.它是从所需的.class文件间接引用的".

我试过添加

import scala.concurrent.ExecutionContext;

但是然后错误只是从承诺所在的行"移动"到文件的顶部,但仍然无法编译.

我也尝试过添加

import play.api.libs.concurrent.Execution.Implicit.defaultContext;

但没有这样的东西可以进口.

Play Framework使用的是2.4.2.

SBT档案:

version := "1.0-SNAPSHOT"

lazy val root = (project in file(".")).enablePlugins(PlayJava)

scalaVersion := "2.11.6"

resolvers ++= Seq(
    "Typesafe repository" at "http://repo.typesafe.com/typesafe/releases/",
    "sonatype snapshots" at "https://oss.sonatype.org/content/repositories/releases/"
)

checksums := Nil

libraryDependencies ++= Seq(
  javaJdbc,
  cache,
  javaWs,
  "org.mockito" % "mockito-all" % "1.10.19",
  "commons-codec" % "commons-codec" % "1.10",
  "de.flapdoodle.embed" % "de.flapdoodle.embed.mongo" % "1.48.0",
  "org.mongodb.morphia" % "morphia" % "1.0.0-rc0"
)

libraryDependencies += "org.mongodb" % "mongodb-driver" % "3.0.2"

// Play provides two styles of routers, one expects its actions to be injected, the
// other, legacy style, accesses its actions statically.
routesGenerator := InjectedRoutesGenerator

Answer 1

我遇到了同样的问题,并意识到我的Play Eclipse设置不完整(我错过了下面的第2步和第3步).我重复了设置,这次是按照所有相关步骤进行的.ExecutionContext然后变得可解析.

播放Eclipse安装程序的说明

原始参考:https://www.playframework.com/documentation/2.4.x/IDE

更新参考:https://www.playframework.com/documentation/2.5.x/IDE

1)将此行附加到project/plugins.sbt:

addSbtPlugin("com.typesafe.sbteclipse" % "sbteclipse-plugin" % "4.0.0")

2)将此行附加到build.sbt:

EclipseKeys.preTasks := Seq(compile in Compile)

3)将这些行附加到build.sbt(假设您没有Scala源):

EclipseKeys.projectFlavor := EclipseProjectFlavor.Java           // Java project. Don't expect Scala IDE
EclipseKeys.createSrc := EclipseCreateSrc.ValueSet(EclipseCreateSrc.ManagedClasses, EclipseCreateSrc.ManagedResources)  // Use .class files instead of generated .scala files for views and routes 

4)保存所有项目文件.关闭Eclipse.

5)在命令提示符下,cd运行到项目文件夹并运行:

activator "eclipse with-source=true"

6)打开Eclipse.打开你的项目.刷新如下:

Package Explorer>右键单击your_project> refresh