我必须为Play Framework过滤器导入哪个包

Question

我需要导入哪些软件包才能从playframework document获取此代码。

scalaVersion := "2.11.7"

libraryDependencies ++= Seq( javaJdbc ,  cache , javaWs, filters)

libraryDependencies += "com.typesafe.akka" %% "akka-stream" % "2.4.2"

libraryDependencies += "com.typesafe.play" % "filters-helpers_2.11" % "2.4.2"

libraryDependencies += "com.google.code.gson" % "gson" % "2.8.0"

unmanagedResourceDirectories in Test <+=  baseDirectory ( _ /"target/web/public/test" )  

resolvers += "scalaz-bintray" at "https://dl.bintray.com/scalaz/releases"  

错误是扩展过滤器sais找不到符号过滤器

由于

build.sbt

{{1}}

Answer 1

看起来它必须是mvc包中的过滤器：

import play.mvc.Filter;

您的代码有import play.mvc.*;，所以

  

错误是扩展过滤器sais找不到符号过滤器

不得出现。

<强>修正

您需要将setHeader更改为withHeader：

import java.util.concurrent.CompletionStage;
import java.util.function.Function;
import javax.inject.Inject;
import akka.stream.Materializer;
import play.mvc.*;


public class GlobalHeaders extends Filter {

    @Inject
    public GlobalHeaders(Materializer mat) {
        super(mat);
    }

    @Override
    public CompletionStage<Result> apply(Function<Http.RequestHeader, CompletionStage<Result>> nextFilter,Http.RequestHeader requestHeader) {

        return nextFilter.apply(requestHeader).thenApply(result -> {
            return result.withHeader("Access-Control-Allow-Origin", "*")
                    .withHeader("Allow", "*")
                    .withHeader("Access-Control-Allow-Methods", "POST, GET, PUT, DELETE, OPTIONS")
                    .withHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept, Referer, User-Agent");
        });
    }
}

图库修复

如果您使用Play作为第三方库，则需要添加过滤器作为依赖项，例如：

的Maven：

<!-- https://mvnrepository.com/artifact/com.typesafe.play/filters-helpers_2.11 -->
<dependency>
    <groupId>com.typesafe.play</groupId>
    <artifactId>filters-helpers_2.11</artifactId>
    <version>2.5.14</version>
</dependency>

SBT：

// https://mvnrepository.com/artifact/com.typesafe.play/filters-helpers_2.11
libraryDependencies += "com.typesafe.play" % "filters-helpers_2.11" % "2.5.14"

标准安装

如果您使用标准播放安装，请不要将filters包含在libraryDependencies的{​​{1}}中。 Play已经拥有它，所以再添加一次就会发生冲突。

Play文档没有说过将过滤器添加为依赖项： https://www.playframework.com/documentation/2.5.x/ScalaHttpFilters