Servlet3.0

一、Servlet3.0介绍

Servlet3.0提供了注解(annotation)，使得不再需要在web.xml文件中进行Servlet的部署描述，简化开发流程。

二、开发Servlet3.0程序的所需要的环境

　　开发Servlet3.0的程序需要一定的环境支持。Tomcat7都提供了对Java EE6规范的支持。Tomcat需要Tomcat7才支持Java EE6，Tomcat7需要使用JDK1.6以上的版本。

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
                      http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
  version="3.0">
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

新建一个测试的Servlet

package mine.service;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;




/**
 * Servlet implementation class TestServlet
 */

@WebServlet("/TestServlet.do")
public class TestServlet extends HttpServlet {
	

	
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public TestServlet() {
        super();
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

		response.getWriter().write("Hello Servlet3.0");
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

		response.getWriter().write("Hello Servlet3.0");
	}

}

 代码中的 @WebServlet("/TestServlet.do") 就用注解方式配置了该Servlet的访问方式，即用/TestServlet.do 来访问这个Servlet，这样就不需要在web.xml中进行配置了。