上机指导第九章

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于 2023-01-09 21:29:48 发布

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分类专栏： JSP 文章标签： servlet java 前端

本文链接：https://blog.youkuaiyun.com/weixin_56845253/article/details/128621464

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1．编写一个Servlet程序，可显示该Servlet被访问的次数。

<?xml version="1.0" encoding="UTF-8"?>

<web-app version="2.5"

xmlns="http://java.sun.com/xml/ns/javaee"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://java.sun.com/xml/ns/javaee

" target="_blank">http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

<display-name></display-name>

<description>This is the description of my J2EE component</description>

<display-name>This is the display name of my J2EE component</display-name>

<servlet-name>CounterServlet</servlet-name>

<servlet-class>com.inspur.ch9.CounterServlet</servlet-class>

</servlet>

<description>This is the description of my J2EE component</description>

<display-name>This is the display name of my J2EE component</display-name>

<servlet-name>Ch9Servlet2</servlet-name>

<servlet-class>com.inspur.ch9.Ch9Servlet2</servlet-class>

</servlet>

<servlet-mapping>

<servlet-name>CounterServlet</servlet-name>

<url-pattern>/servlet/CounterServlet</url-pattern>

</servlet-mapping>

<servlet-mapping>

<servlet-name>Ch9Servlet2</servlet-name>

<url-pattern>/servlet/Ch9Servlet2</url-pattern>

</servlet-mapping>

<welcome-file-list>

<welcome-file>index.jsp</welcome-file>

</welcome-file-list>

</web-app>

package com.inspur.ch9;

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 CounterServlet extends HttpServlet {

/**

* Constructor of the object.

public CounterServlet() {

super();

}

/**

* Destruction of the servlet. <br>

public void destroy() {

super.destroy(); // Just puts "destroy" string in log

// Put your code here

}

/**

* The doGet method of the servlet. <br>

* This method is called when a form has its tag value method equals to get.

* @param request the request send by the client to the server

* @param response the response send by the server to the client

* @throws ServletException if an error occurred

* @throws IOException if an error occurred

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

Integer counter=(Integer)this.getServletContext().getAttribute("counter");

if(counter==null){

counter=new Integer(0);

}

counter++;

this.getServletContext().setAttribute("counter", counter);

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(" This Servlet is accessed ");

out.print(counter.toString());

out.println(" times.");

out.println(" </BODY>");

out.println("</HTML>");

out.flush();

out.close();

}

/**

* The doPost method of the servlet. <br>

* This method is called when a form has its tag value method equals to post.

* @param request the request send by the client to the server

* @param response the response send by the server to the client

* @throws ServletException if an error occurred

* @throws IOException if an error occurred

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

Integer counter=(Integer)this.getServletContext().getAttribute("counter");

if(counter==null){

counter=new Integer(0);

}

counter++;

this.getServletContext().setAttribute("counter", counter);

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(" This Servlet is accessed ");

out.print(counter.toString());

out.println(" times.");

out.println(" </BODY>");

out.println("</HTML>");

out.flush();

out.close();

}

/**

* Initialization of the servlet. <br>

* @throws ServletException if an error occurs

public void init() throws ServletException {

// Put your code here

}

2. 编写一个Servlet程序，在doGet方法中显示一个Form表单，用户可以输入姓名和电子邮件地址，用户提交该表单后，doPost方法动态读出请求参数，并输出这些参数。

<?xml version="1.0" encoding="UTF-8"?>

<web-app version="2.5"

xmlns="http://java.sun.com/xml/ns/javaee"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://java.sun.com/xml/ns/javaee

" target="_blank">http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

<display-name></display-name>

<description>This is the description of my J2EE component</description>

<display-name>This is the display name of my J2EE component</display-name>

<servlet-name>CounterServlet</servlet-name>

<servlet-class>com.inspur.ch9.CounterServlet</servlet-class>

</servlet>

<description>This is the description of my J2EE component</description>

<display-name>This is the display name of my J2EE component</display-name>

<servlet-name>Ch9Servlet2</servlet-name>

<servlet-class>com.inspur.ch9.Ch9Servlet2</servlet-class>

</servlet>

<servlet-mapping>

<servlet-name>CounterServlet</servlet-name>

<url-pattern>/servlet/CounterServlet</url-pattern>

</servlet-mapping>

<servlet-mapping>

<servlet-name>Ch9Servlet2</servlet-name>

<url-pattern>/servlet/Ch9Servlet2</url-pattern>

</servlet-mapping>

<welcome-file-list>

<welcome-file>index.jsp</welcome-file>

</welcome-file-list>

</web-app>

package com.inspur.ch9;

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 Ch9Servlet2 extends HttpServlet {

/**

* Constructor of the object.

public Ch9Servlet2() {

super();

}

/**

* Destruction of the servlet. <br>

public void destroy() {

super.destroy(); // Just puts "destroy" string in log

// Put your code here

}

/**

* The doGet method of the servlet. <br>

* This method is called when a form has its tag value method equals to get.

* @param request the request send by the client to the server

* @param response the response send by the server to the client

* @throws ServletException if an error occurred

* @throws IOException if an error occurred

public void doGet(HttpServletRequest request, HttpServletResponse resp)

throws ServletException, IOException {

resp.setContentType("text/html;charset=utf-8");

PrintWriter out = resp.getWriter();

out.print("<html>");

out.print("<head><title>用户注册界面</title></head>");

out.println("<body><form method='post'>用户名：<input type='text' name='userName'" +

"/><br>电子邮件：<input type='text' name='mail'/><br/>" +

"<input type='submit' value='确定'/></form></body>");

out.print("</html>");

out.flush();

out.close();

}

public void doPost(HttpServletRequest request, HttpServletResponse resp)

throws ServletException, IOException {

resp.setContentType("text/html;charset=utf-8");

request.setCharacterEncoding("utf-8");

PrintWriter out = resp.getWriter();

out.print("<html>");

out.print("<head><title>用户注册界面</title></head>");

out.println("<body>用户名：" +request.getParameter("userName")+

"<br>电子邮件：" +request.getParameter("mail")+

"</body>");

out.print("</html>");

out.flush();

out.close();

}

/**

* Initialization of the servlet. <br>

* @throws ServletException if an error occurs

public void init() throws ServletException {

// Put your code here

}