1.概念

Servlet：Servlet Apple的簡稱，是服務器端的程序(代碼，功能實現)，可交互的處理客戶端發送到服務端的請求，并完成操作響應

動態網頁技術

JavaWeb程序開發的基礎，JavaEE規范(一套接口)的一個組成部分。

2.Servlet作用

接收客戶端請求，完成操作

動態生成網頁(頁面數據可變)

將包含操作結果的動態網頁響應給客戶端

3.Servlet開發步驟

(1)搭建開發環境

將Servlet相關的jar包(lib\servlet-api.jar)配置到classpath中

(2)編寫Servlet

實現javax.servlet.Servlet

重寫5個主要方法

在核心的service()方法中編寫輸出語句，打印訪問結果

MyServlet.java

import java.io.IOException; 
import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
public class MyServlet implements Servlet { 
    @Override
    public void destroy() {
        // TODO Auto-generated method stub 
    } 
    @Override
    public ServletConfig getServletConfig() {
        // TODO Auto-generated method stub
        return null;
    } 
    @Override
    public String getServletInfo() {
        // TODO Auto-generated method stub
        return null;
    } 
    @Override
    public void init(ServletConfig arg0) throws ServletException {
        // TODO Auto-generated method stub 
    } 
    @Override
    public void service(ServletRequest arg0, ServletResponse arg1) throws ServletException, IOException {
        // TODO Auto-generated method stub
		System.out.println("My First servlet"); 
    } 
}

(3)部署Servlet

編譯MyServlet后，將生成的class文件放在WEB-INF/classes文件中

(4)配置Servlet

編寫WEB-INF下項目配置文件web.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--
 Licensed to the Apache Software Foundation (ASF) under one or more
  contributor license agreements.  See the NOTICE file distributed with
  this work for additional information regarding copyright ownership.
  The ASF licenses this file to You under the Apache License, Version 2.0
  (the "License"); you may not use this file except in compliance with
  the License.  You may obtain a copy of the License at
      http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
-->
<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"
  metadata-complete="true"> 
 <servlet>
	<servlet-name>my</servlet-name>
	<servlet-class>MyServlet</servlet-class>
 </servlet> 
 <servlet-mapping>
	<servlet-name>my</servlet-name>
	<url-pattern>/myservlet</url-pattern>
 </servlet-mapping> 
</web-app>

注意：url-pattern 配置的內容就是瀏覽器地址欄輸入的url中項目名稱后資源的內容

(5)運行測試

啟動Tomcat，在瀏覽器地址欄中輸入http://localhost:8080/myweb/myservlet訪問，在Tomcat中打印時間表示成功