内容提要：本文以一个“Hello World”的简单例子，开始servlet之旅。
开发环境：eclipse3.5+jdk6.0+tomcat7.0
详细步骤：
1、打开 Eclipse，新建 Dynamic Web Project项目，项目名为test
2、在Java Resources -->src目录新建一个class，文件名为Hello.java，代码如下：
import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class Hello extends HttpServlet { public Hello() { super(); } public void destroy() { super.destroy(); } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">"); out.println("<HTML>"); out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>"); out.println(" <BODY>"); out.print("hello world ! This is "); out.print(this.getClass()); out.println(", using the GET method!"); out.println("</BODY>"); out.println("</HTML>"); out.flush(); out.close(); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">"); out.println("<HTML>"); out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>"); out.println(" <BODY>"); out.print(" hello world! This is "); out.print(this.getClass()); out.println(", using the POST method"); out.println(" </BODY>"); out.println("</HTML>"); out.flush(); out.close(); } }
3、在 WEB-INF 目录下，新建一个xml文件，文件名web.xml，代码如下：
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5"> <servlet> <servlet-name>Hello</servlet-name> <servlet-class>Hello</servlet-class> </servlet> <servlet-mapping> <servlet-name>Hello</servlet-name> <url-pattern>/servlet/Hello</url-pattern> </servlet-mapping> </web-app>
4、启动Tomcat Server，打开浏览器，输入http://localhost:8080/test/servlet/Hello，回车，页面显示如下：