Play 2.2.1 Java:与 play 1.X 中的 @before 过滤器等价的是什么? [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，将用户对象放入上下文中，如 Http.Context.current().args.put("user", 用户);

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

应该在每个控制器方法之前应用此方法，以便视图可以访问用户的隐式访问权限.

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

使用 Play1，我创建了一个 BaseController，它调用这个方法before所有请求(@Before 过滤器)和扩展来自这个控制器的所有其他控制器.

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 中使用 Java API 实现类似的功能?

似乎有一些适用于 Scala 但适用于 Java 的东西?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

虽然你可以使用过滤器 (or Interceptors) 在传统"的 webapp 框架方式中，Play 首选方式似乎肯定是组合自定义 Action 方法；请参阅有关动作组合的文档.

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.

如果您遵循他们的风格，您将定义一个新的 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);
    }

}

你最终会得到如下所示的控制器代码:

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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