Servlet是接受http请求进行处理并作出响应的实现了 javax.servlet.Servlet 接口的Java类。下面我们在Eclipse中创建一个工程，实现一个Servlet。
创建工程
在Eclipse中，依次选择File > New > Other > Web > Dynamic Web Project创建一个Web工程，工程名为servletTest。然后选择File > New > Other > Web > Servlet，创建一个Servlet类。
代码如下：
package com.vosamo.serv;
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;
/**
* Servlet implementation class ServTest
*/
public class ServTest extends HttpServlet {
private static final long serialVersionUID = 1L;
private String message;
/**
* @see HttpServlet#HttpServlet()
*/
public ServTest() {
super();
// TODO Auto-generated constructor stub
}
/* (non-Javadoc)
* @see javax.servlet.GenericServlet#init()
*/
@Override
public void init() throws ServletException {
// TODO Auto-generated method stub
message = "Hello World! Hello Inspur!";
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 设置响应内容类型
response.setContentType("text/html");
// 实际的逻辑是在这里
PrintWriter out = response.getWriter();
out.println("<h1>" + message + "</h1>"); }
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}在WEB-INF下，web.xml文件中可以看到Servlet类的配置：
<servlet>
<description></description>
<display-name>ServTest</display-name>
<servlet-name>ServTest</servlet-name>
<servlet-class>com.vosamo.serv.ServTest</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ServTest</servlet-name>
<url-pattern>/ServTest</url-pattern>
</servlet-mapping>
访问Servlet
启动Tomcat，在浏览器中输入http://localhost:8080/servletTest/ServTest可以看到message内容。