javascript - 如何在 play-framework 2.5.x 中实现跨源资源共享 (CORS)

Question

我正在尝试使用 Angularjs-1 应用程序通过从本地主机访问 Restful URL 来获取 json 数据。

我收到这个错误

http://localhost:9000/mlm/user/all Failed to load resource: 
the server responded with a status of 404 (Not Found)

index.html:1 XMLHttpRequest cannot load http://localhost:9000/mlm/user/all. 

Response to preflight request doesn't pass access control check:
No 'Access-Control-Allow-Origin' header is present on the requested resource.

Origin 'http://localhost:63342' is therefore not allowed access. 

The response had HTTP status code 404.

我正在使用 play-framework 2.5.4 (java)。

编辑 1:将 CORS 设置添加到 app.conf

    play.filters {
    cors {
    # Filter paths by a whitelist of path prefixes
    pathPrefixes = ["/"]

    # The allowed origins. If null, all origins are allowed.
    allowedOrigins = null

    # The allowed HTTP methods. If null, all methods are allowed
    allowedHttpMethods = ["GET", "POST"]

    allowedHttpHeaders = ["Accept"]
    preflightMaxAge = 3 days
  }
}

Answer 1

最后这对我有用。

根据 official文档

Filter.java 是(没有工作):

import play.mvc.EssentialFilter;
import play.filters.cors.CORSFilter;
import play.http.DefaultHttpFilters;

import javax.inject.Inject;

public class Filters extends DefaultHttpFilters {
    @Inject public Filters(CORSFilter corsFilter) {
        super(corsFilter);
    }
}

但它确实奏效了。有效的是:

Filter.java(有效)

import play.mvc.EssentialFilter;
import play.filters.cors.CORSFilter;
import play.http.HttpFilters;
import javax.inject.Inject;

public class Filters implements HttpFilters {

    @Inject
    CORSFilter corsFilter;

    public EssentialFilter[] filters() {
        return new EssentialFilter[] { corsFilter.asJava() };
    }
}

感谢this回答，关于堆栈溢出的类似问题。

但是为什么官方的Filter.java代码docs 2.5.x 不工作是百万美元的问题？