java - 什么是 Play 中的请求响应周期

Question

我刚刚开始研究play 2.0，虽然到目前为止它不是很复杂，但我没有得到非常基本的东西，即请求响应周期。我想要一个 JAVA Play 的请求响应周期的最小示例

Answer 1

Basically a request is handled by the HTTP router, which gets an url, eg: mydomain.com/details/. Then it tries to look this entry up in your routes config file. At the first matching line in the routes file, there's a corresponding method for that (a controller method), so it invokes the controller method, which will return an html response parameteriized by a view to be rendered.

Simplified: request (url) -> find the route in routes table -> call static controller method -> return an html response with the view

(also you can parameterize the url, eg: /details/12 and in the routes table: /details/:id, so you can pass the id to the controller method)

Another thing: it is also possible to do "reverse routing" which is parameterizing eg. a button to call a controller method directly, and it will find the corresponding url from the routes file

the official documentation is pretty good in this topic: http://www.playframework.org/documentation/2.0.2/JavaRouting

Answer 2

我想指出的是，如果你想通过 POST 传递数据，你必须将你的请求绑定到某个模型字段，然后在你的应用程序中检索传递的数据：像这样：

你的html：

<form action="/login" method="POST">
<input name="username"/>
...
</form>

你的路线：

POST  /login      controllers.Application.login()

你的申请：

public static Result login(){
Form<User> passedform = form(User.class).bindFromRequest();
if(passedform.hasErrors){
return badRequest("shit").as("text/plain");
} else {
User user = passedform.get();
System.out.print(user.username);
  }
}

现在输出是您在输入字段中给出的用户名..这将以这种方式工作 python/django：

def login(request):
  print(request.POST.get('username'))

:))) 但无论如何，游戏也很漂亮

希望我能帮助你