播放2.2.1 Java：相当于播放1.X的@before过滤器？ [英] Play 2.2.1 Java: Whats the equivalent of @before filters from play 1.X?

问题描述

我想实现一个 setUserIfPresent （）方法，该方法将用户对象放入上下文，如Http.Context.current（）。args.put（user ，user）;

I want to implement a setUserIfPresent() method that puts a user object into the context like Http.Context.current().args.put("user", user);

此方法应在之前应用于每个控制器方法，以便视图可以访问用户的隐式访问权。

This method should be applied before every controller method so that views have access implicit access to the user.

使用Play1我创建 BaseController ，调用此方法 之前所有请求（@Before过滤器）和扩展所有其他控制器。

With Play1 I create a BaseController that invokes this method before all requests (@Before filter) and extended all other controllers from this one.

如何在play2中实现类似的功能Java API？

看起来像Scala有什么东西可用于Java？ http://www.playframework.com/documentation/2.2.x/ScalaHttpFilters

Seems like there is something for Scala but for Java? http://www.playframework.com/documentation/2.2.x/ScalaHttpFilters

干杯

推荐答案

当你可以使用传统webapp框架方式的过滤器（或拦截器）， Play首选方式似乎绝对是组成自定义 Action 方法;请参阅有关 Action Composition 的文档。

While you could use filters (or Interceptors) in the "traditional" webapp framework way, the Play-preferred way seems to definitely be to compose custom Action methods; see the documentation on Action Composition.

如果你遵循他们的风格，你将定义一个新的 Action 实现，如下所示：

If you follow their style, you'll define a new Action implementation like this:

public class UserContextInjectingAction extends play.mvc.Action.Simple {

    public F.Promise<SimpleResult> call(Http.Context ctx) throws Throwable {
        Logger.info("Injecting user data into context " + ctx);
        injectUser(ctx); // Written by you
        return delegate.call(ctx);
    }

}

你最终得到了控制器代码如下所示：

And you'd end up with controller code that looks like this:

@With(UserContextInjectingAction.class)
public static Result showHomePage() {
    return ok("Welcome");
}   

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