您刚刚得到了一个正常servlet的答案。但是，我想与您分享一些关于Servlet 3.0的内容

What is first a Servlet? A servlet is a Web component that is managed by a container and generates dynamic content. Servlets are Java classes that are compiled to byte code that can be loaded dynamically into and run by a Java technology-enabled Web server or Servlet container. Servlet 3.0 is an update to the existing Servlet 2.5 specification. Servlet 3.0 required API of the Java Platform, Enterprise Edition 6. Servlet 3.0 is focussed on extensibility and web framework pluggability. Servlet 3.0 bring you up some extensions such as Ease of Development (EoD), Pluggability, Async Support and Security Enhancements Ease of Development You can declare Servlets, Filter, Listeners, Init Params, and almost everything can be configured by using annotations Pluggability You can create a sub-project or a module with a web-fragment.xml. It means that it allows to implement pluggable functional requirements independently. Async Support Servlet 3.0 provides the ability of asynchronous processing, for example: Waiting for a resource to become available, Generating response asynchronously. Security Enhancements Support for the authenticate, login and logout servlet security methods

我从Java Servlet教程中找到的

什么是Servlet?

A servlet is simply a class which responds to a particular type of network request - most commonly an HTTP request. Basically servlets are usually used to implement web applications - but there are also various frameworks which operate on top of servlets (e.g. Struts) to give a higher-level abstraction than the "here's an HTTP request, write to this HTTP response" level which servlets provide. Servlets run in a servlet container which handles the networking side (e.g. parsing an HTTP request, connection handling etc). One of the best-known open source servlet containers is Tomcat. In a request/response paradigm, a web server can serve only static pages to the client To serve dynamic pages, a we require Servlets. Servlet is nothing but a Java program This Java program doesn’t have a main method. It only has some callback methods. How does the web server communicate to the servlet? Via container or Servlet engine. Servlet lives and dies within a web container. Web container is responsible for invoking methods in a servlets. It knows what callback methods the Servlet has.

请求流程

Client sends HTTP request to Web server Web server forwards that HTTP request to web container. Since Servlet can not understand HTTP, its a Java program, it only understands objects, so web container converts that request into valid request object Web container spins a thread for each request All the business logic goes inside doGet() or doPost() callback methods inside the servlets Servlet builds a Java response object and sends it to the container. It converts that to HTTP response again to send it to the client

容器如何知道哪个Servlet客户端请求了?

有一个文件叫web。xml 这是web容器的主文件 在这个文件中有关于servlet的信息- servlet Servlet-name servlet类 servlet-mappings-类似/Login或/Notifications的路径映射在这里 Servlet-name url模式 等等 web应用程序中的每个servlet都应该在这个文件中有一个条目 查找的方式是- url-pattern -> servlet-name -> servlet-class

如何“安装”servlet ? servlet对象继承自javax.servlet库。*。Tomcat和Spring可以用来利用这些对象来适应用例。

参考-在1.5x上观看- https://www.youtube.com/watch?v=tkFRGdUgCsE。这有一个很棒的解释。

如果你是初学者，我认为本教程可能会给出什么是Servlet的基本概念…

以下是一些有价值的观点。

利用Servlet技术创建web应用程序，该应用程序驻留在服务器端，生成动态网页。

Servlet可以根据上下文以多种方式描述。

Servlet是一种用于创建web应用程序的技术。 Servlet是一个API，它提供了许多接口和类，包括 文件。 Servlet是一个必须实现的接口，用于创建任何 servlet。 Servlet是一个扩展服务器和服务器功能的类 响应传入的请求。它可以对任何类型的 请求。 Servlet是部署在服务器上用于创建的web组件 动态网页。 参考:在这里。

除了以上，只是要指出流血的明显……

To many this is hyper obvious, but to someone used to writing apps which are just run and then end: a servlet spends most of its time hanging around doing nothing... waiting to be sent something, a request, and then responding to it. For this reason a servlet has a lifetime: it is initalised and then waits around, responding to anything thrown at it, and is then destroyed. Which implies that it has to be created (and later destroyed) by something else (a framework), that it runs in its own thread or process, and that it does nothing unless asked to. And also that, by some means or other, a mechanism must be implemented whereby this "entity" can "listen" for requests.

我建议阅读有关线程、进程和套接字的内容可以让你对此有所了解:这与一个基本的“hello world”应用程序的功能方式是完全不同的。

有人可能会说，术语“服务器”或“servlet”有点大材小用。一个更合理、更简单的名字可能是“responder”。选择术语“服务器”的原因是历史的:第一个这样的安排是“文件服务器”，多个用户/客户端终端将从中央机器请求特定的文件，然后该文件将像一本书或一盘炸鱼和薯条一样被“提供”。

Servlet是一个java类，用于响应HTTP请求并生成HTTP响应......当我们使用HTML创建页面时，它将是一个静态页面，因此为了使其动态，我们使用SERVLET{简单地说，人们可以理解}。 JSP克服了利用servlet的问题，它本身就使用了代码和HTML标记。

正如本文所描述的，Servlet是一种扩展Java服务器并访问其功能的标准化方式。

每个Servlet都可以被视为一个小型服务器(因此得名)，它可以访问用Java代码建模的请求和响应，以及其他上下文数据，比如Session。

有了这些，servlet的Java代码就可以与它所需要的任何东西交互以呈现响应，包括交给JSP页面来生成HTML视图。