本文主要简单实践一下servlet开发相关开发
1、Servlet的创建
两种方法：
- 创建普通的java类，继承自HttpServlet类，在通过手动配置web.xml文件注册Servlet对象，比较复杂
- 直接通过IDE集成开发工具进行创建
下面采用IDE的方法创建，具体步骤如下：
（1）创建一个动态的web项目，然后在包资源管理器中新建项目的名字上右键新建Servlet
（2）单击下一步，进入Servlet部署描述信息的页面，采用默认的配置
（3）继续下一步，进入选择修饰符、实现接口和生成的方法界面，采用默认设置，完成Servlet的创建
创建完Servlet后，打开相应的页面：
package com.wuyudong.www; 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 实现类 FirstServlet */ @WebServlet("/FirstServlet") public class FirstServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() * 构造方法 */ public FirstServlet() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub //业务处理 } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub //业务处理 } }
2、Servlet配置的相关元素
1、声明Servlet对象
在web.xml中，通过 <servlet>标签声明一个servlet对象
<servlet-name>元素指定Servlet的名称
<servlet-class>元素用于指定Servlet对象的完整位置，包含Servlet对象的包名和类名
<servlet> <servlet-name>SimpleServlet</servlet-name> <servlet-class>com.lyq.SimpleServlet</servlet-class> </servlet>
2、映射Sevlet
映射访问Servlet的url，使用<servlet-mapping>标签进行配置，分别包含 <servlet-name>和<url-pattern>。
配置如下：
<servlet-mapping> <servlet-name>SimpleSevlet</servlet-name> <url-pattern>/SimpleSevlet</url-pattern> </servlet-mapping>
实践一下：
新建MyServlet.java
package com.wuyudong; 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; /** * Servlet implementation class MyServlet */ @WebServlet("/MyServlet") public class MyServlet extends HttpServlet { private static final long serialVersionUID = 3563565034243126713L; public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); response.setCharacterEncoding("GBK"); PrintWriter out = response.getWriter(); out.println("<HTML>"); out.println(" <HEAD><TITLE>Servlet实例</TITLE></HEAD>"); out.println(" <BODY>"); out.print(" Servlet实例： "); out.print(this.getClass()); out.println(" </BODY>"); out.println("</HTML>"); out.flush(); out.close(); } }
web.xml
<servlet> <servlet-name>MyServlet</servlet-name> <servlet-class>com.wuyudong.MyServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>MyServlet</servlet-name> <url-pattern>/servlet/MyServlet</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>servlet/MyServlet</welcome-file> </welcome-file-list>