首先，根据 http://my.oschina.net/letiantian/blog/366964的介绍创建项目HelloJSP。
右击项目，New -> Servlet... ->：
在Class Name中输入letian.servlet.HelloWorld，然后点击“Next”。
将 url pattern修改为 /hello，点击“Finish”。
由上图可以看到，在目录src/java/letian/servlet下生成了文件HelloWorld.java，内容如下：
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package letian.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
*
* @author letian
*/
@WebServlet(name = "HelloWorld", urlPatterns = {"/hello"})
public class HelloWorld extends HttpServlet {
/**
* Processes requests for both HTTP <code>GET</code> and <code>POST</code>
* methods.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
try (PrintWriter out = response.getWriter()) {
/* TODO output your page here. You may use following sample code. */
out.println("<!DOCTYPE html>");
out.println("<html>");
out.println("<head>");
out.println("<title>Servlet HelloWorld</title>");
out.println("</head>");
out.println("<body>");
out.println("<h1>Servlet HelloWorld at " + request.getContextPath() + "</h1>");
out.println("</body>");
out.println("</html>");
}
}
// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
* Handles the HTTP <code>GET</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Handles the HTTP <code>POST</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Returns a short description of the servlet.
*
* @return a String containing servlet description
*/
@Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>
}
可以看到，通过注解的方式将/hello绑定到了HelloWorld这个类（也是Servlet）上。
运行项目，浏览器访问http://localhost:8080/HelloJSP/hello，可以看到：
在Tomcat的安装目录下的 conf/Catalina/localhost目录下出现了文件 HelloJSP.xml，其内容如下：
<?xmlversion="1.0"encoding="UTF-8"?>
<ContextantiJARLocking="true"docBase="/home/letian/NetBeansProjects/HelloJSP/build/web"path="/HelloJSP"/>
我们看一下build/web目录下的内容：
上面的HelloWord类使用注解绑定了url，其实也可以通过web.xml来配置（这也是更古老的方式）：
首先删除HelloWord类的注解，然后将web/WEB-INF/web.xml修改为：
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
version="3.1">
<session-config>
<session-timeout>
30
</session-timeout>
</session-config>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>helloWorld</servlet-name>
<servlet-class>letian.servlet.HelloWorld</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>helloWorld</servlet-name>
<url-pattern>/hello</url-pattern>
</servlet-mapping>
</web-app>
即可。
