第5章 Servlet技术【首页】杜老师

Servlet知识点备忘录

(1) Servlet备忘录

1. Servlet(继承HttpServlet的java类)
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class XXXXXX extends HttpServlet {
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		...
	}
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		...
	}
	protected void service(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		...
	}
}
	(1) import 5个类：IOException, ServletException, HttpServlet, HttpServletRequest, HttpServletResponse;
	(2) public class XXXXXX extends HttpServlet {...}
	(3) init/doGet/doPost/service/destroy方法；
2. WebRoot\WEB-INF\web.xml
	<servlet>
		<servlet-name>Servlet名称</servlet-name>
		<servlet-class>保护包名的类全名</servlet-class>
	</servlet>
	<servlet-mapping>
		<servlet-name>Servlet名称</servlet-name>
		<url-pattern>含路径的访问的URL</url-pattern>
	</servlet-mapping>
3. 页面

(2) Filter备忘录

1. Filter(实现Filter的java类)
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class XXXXXX implements Filter {
 public void init(FilterConfig filterConfig) throws ServletException {
 //初始化代码
 }
 public void destroy() {
 //销毁代码
 }
 public void doFilter(ServletRequest request, ServletResponse response,
 FilterChain chain) throws IOException, ServletException {
 //过滤代码
 chain.doFilter(request, response);//调用下一个Filter或者其他原始内容
 }
}
	(1) import 7个类：IOException, Filter, FilterChain, FilterConfig, ServletException, HttpServletRequest, HttpServletResponse;
	(2) public class XXXXXX implements Filter {...}
	(3) init/destroy/doFilter方法；
2. WebRoot\WEB-INF\web.xml
	<filter>
		<filter-name>Filter名称<</filter-name>
		<filter-class>含包名的类全名</filter-class>
		<init-param>
			<param-name>参数名</param-name>
			<param-value>参数值</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>Filter名称</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>

(3) Listener备忘录

1. Listener(实现接口的java类, Servlet 2.4共有三类8个Listener接口, 6个Event类)
(1) Servlet上下文监听器(ServletContext)；
ServletContextListener：监听ServletContext对象的创建和销毁。
	contextInitialized(ServletContextEvent sce): ServletContext对象创建
	contextDestroryed(ServletContextEvent sce): 销毁
ServletContextAttributeListener: 监听ServletContext对象中属性的增删改操作。 
	attributeAdded(ServletContextAttributeEvent scae): 添加ServletContext对象属性
	attributeRemoved(ServletContextAttributeEvent scae): 删除
	attributeReplaced(ServletContextAttributeEvent scae): 修改
(2) 客户端请求监听器(ServletRequest)。
ServletRequestListener: 监听用户请求的到达
	void requestInitialized(ServletRequestEvent sre): 用户请求到底、被初始化时触发
	void requestDestroyed(ServletRequestEvent sre): 用户请求结束、被销毁时触发
ServletRequestAttributeListener 监听ServletRequest(request)范围内属性的变化
	attributeAdded(ServletRequestAttributeEvent event)
	attributeRemoved(ServletRequestAttributeEvent event)
	attributeReplaced(ServletRequestAttributeEvent event)
(3) Http会话监听器(HttpSession)；
HttpSessionListener: 监听整个应用中的所有session
	sessionCreated(HttpSessionEvent hse): 当前应用中session的创建
	sessionDestroyed(HttpSessionEvent hse): 的销毁
HttpSessionAttributeListener
	attributeAdded(HttpSessionBindingEvent se): 当往HttpSession对象中添加属性时
	attributeRemoved(HttpSessionBindingEvent se): 移除属性时
	attributeReplaced(HttpSessionBindingEvent se): 属性改变时
HttpSessionBindingListener: 监听应用中的某个session
	valueBound(HttpSessionBindingEvent hsbe) 数据绑定
	valueUnbound(HttpSessionBindingEvent hsbe)取消绑定
HttpSessionActivationListener
	sessionDidActivate(HttpSessionEvent se) 
	sessionWillPassivate(HttpSessionEvent se)
2. WebRoot\WEB-INF\web.xml
	<listener>
		<listener-class>含包名的类全名</listener-class>
	</listener>

0. 【首页】及配置文件

创建web项目：01JavaWeb05, 01学号, html：WebRoot\index.jsp

<%@ page language="java" pageEncoding="gbk"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
 <head>
 <base href="<%=basePath%>">
 <title>第5章 Servlet技术【首页】</title>
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0"> 
 </head>
 <body>
 <h1>第5章 Servlet技术【首页】杜老师</h1>
 <hr />
 <a href="slet/hello01">1. Hello, Servlet!</a> 
 <a href="slet/lifeCycle01">2. Servlet生命周期(Tomcat控制台)</a> 
 3. TestGetPost 测试GetPost 
 <a href="slet/csgp01">  3.1 测试GetPost方法!(slet/csgs01)</a> 
 <a href="GetForm01.jsp">  3.2 测试GetPost方法!(GetForm01.jsp)</a> 
 <a href="PostForm01.jsp">  3.3 测试GetPost方法!(PostForm01.jsp)</a> 
 4. 过滤器测试:(Tomcat控制台输出:执行过滤)! 
 <a href="slet/hello01">  4.1 执行Hello, Servlet!</a> 
 <a href="GetForm01.jsp">  4.2 执行GetForm01.jsp</a> 
 <a href="PostForm01.jsp">  4.3 执行PostForm01.jsp</a> 
 5. IP地址过滤器(浏览器输出：该IP地址被禁止访问，请联系管理员!)! 
 <a href="getRemoteIp01.jsp">  获取客户端远程ip地址</a> 
   如果获取客户端远程ip地址是:127.0.0.1，请复制下列地址到浏览器地址栏测试 
   (1) Hello, Servlet!(http://localhost:8080/01JavaWeb05/slet/hello01) 
   (2) 执行GetForm01.jsp(http://localhost:8080/01JavaWeb05/GetForm01.jsp) 
   (3) 执行PostForm01.jsp(http://localhost:8080/01JavaWeb05/PostForm01.jsp) 
   如果项目部署到外围，获取客户端远程ip地址将是外网地址，请在web.xml中设置ip值后重新部署，将上述地址中localhost改为服务器域名(如www.duzhaojiang.cn)复制到浏览器地址栏测试 
 6. 上下文监听器(TestServletContextListener01)之定义与配置!(Tomcat控制台查看，重新部署项目) 
 <a href="LoginForm01.jsp">实训题. 用户登录、在线用户列表</a> 
 <a href="StudentForm01.jsp">上机题1. 学生注册并显示(使用servlet)</a> 
 <a href="UserInput01.jsp">上机题2. 用户信息输入并重定向(使用servlet，输入：李*、杜*、其他)</a> 
 <a href="LoginForm01_2.jsp">上机题3. 用户登录、验证(使用servlet)</a> 
 <a href="StudentForm01_2.jsp">上机题4. 学生注册、保存并显示(使用servlet)</a> 
 <a href="ShowStudentList01.jsp">         显示所有学生</a> 
 <a href="CharForm01.jsp">上机题5. 用户发言————非法文字过滤器(使用Filter，含：你妈的)</a> 
 上机题6. 字符编码过滤器之定义与配置(使用Filter: CharacterFilter01) 
          测试部署前，屏蔽掉用户发言显示ShowContent01.jsp中request.setCharacterEncoding("gbk")进行【<a href="CharForm01.jsp">用户发言</a>】输入汉字测试显示其发音内容(乱码)；测试部署后再进行同样的测试。 
 上机题7. 登陆验证过滤器之定义与配置(使用Filter: LoginFilter01) 
          项目部署后，复制地址栏首页网址首次进入时将转向LoginForm01.jsp登录网页，登录后将不存在转向问题 
 <hr>
 <a href="/html/01JavaWeb.html">返回章节目录</a> 
 
 </body>
</html>

xml：WebRoot\WEB-INF\web.xml

<?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 
	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

<servlet>
		<servlet-name>HiServlet_du</servlet-name>
		<servlet-class>cn.duzhaojiang.servlet.HelloServlet01</servlet-class>
	</servlet>
	
	<servlet-mapping>
		<servlet-name>HiServlet_du</servlet-name>
		<url-pattern>/slet/hello01</url-pattern>
	</servlet-mapping>

<servlet>
		<servlet-name>生命周期</servlet-name>
		<servlet-class>cn.duzhaojiang.servlet.ServletLifeCycle01</servlet-class>
	</servlet>
	<servlet-mapping>
		<servlet-name>生命周期</servlet-name>
		<url-pattern>/slet/lifeCycle01</url-pattern>
	</servlet-mapping>

<servlet>
		<servlet-name>测试GetPost</servlet-name>
		<servlet-class>cn.duzhaojiang.servlet.TestGetPost01</servlet-class>
	</servlet>
	<servlet-mapping>
		<servlet-name>测试GetPost</servlet-name>
		<url-pattern>/slet/csgp01</url-pattern>
	</servlet-mapping>

<servlet>
		<servlet-name>显示学生</servlet-name>
		<servlet-class>cn.duzhaojiang.servlet.PrintStudentServlet01</servlet-class>
	</servlet>
	<servlet-mapping>
		<servlet-name>显示学生</servlet-name>
		<url-pattern>/servlet/PrintStudentServlet</url-pattern>
	</servlet-mapping>

<servlet>
		<servlet-name>重定向杜李</servlet-name>
		<servlet-class>cn.duzhaojiang.servlet.RedirectServlet01</servlet-class>
	</servlet>
	<servlet-mapping>
		<servlet-name>重定向杜李</servlet-name>
		<url-pattern>/servlet/RedirectServlet</url-pattern>
	</servlet-mapping>

<servlet>
		<servlet-name>登录验证</servlet-name>
		<servlet-class>cn.duzhaojiang.servlet.LoginConfServlet01</servlet-class>
	</servlet>
	<servlet-mapping>
		<servlet-name>登录验证</servlet-name>
		<url-pattern>/LoginConfServlet</url-pattern>
	</servlet-mapping> 
	
	 <servlet>
		<servlet-name>保存学生</servlet-name>
		<servlet-class>cn.duzhaojiang.servlet.SaveStudentServlet01</servlet-class>
	</servlet>
	<servlet-mapping>
		<servlet-name>保存学生</servlet-name>
		<url-pattern>/servlet/SaveStudentServlet</url-pattern>
	</servlet-mapping>

<!-- 	<filter>
		<filter-name>非法文字过滤器</filter-name>
		<filter-class>cn.duzhaojiang.filter.CharFilter01</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>非法文字过滤器</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>
	
	<filter>
		<filter-name>字符编码过滤器</filter-name>
		<filter-class>cn.duzhaojiang.filter.CharacterFilter01</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>字符编码过滤器</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>

<filter>
		<filter-name>登陆验证过滤器</filter-name>
		<filter-class>cn.duzhaojiang.filter.LoginFilter01</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>登陆验证过滤器</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>
-->
</web-app>

1. Hello, Servlet!

创建cn.duzhaojiang.servlet包，创建HelloServlet01.java

编写配置文件WebRoot\WEB-INF\web.xml，部署并测试

2. Servlet生命周期

在cn.duzhaojiang.servlet包创建TestGetPost01.java

package cn.duzhaojiang.servlet;

import java.io.PrintWriter;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class TestGetPost01 extends HttpServlet {
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		resp.setContentType("text/html; charset=UTF-8");	// 设置Content-Type字段值
		PrintWriter out = resp.getWriter();				// 获得PrintWriter对象
		out.println("调用doGet方法 ");
	}
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		resp.setContentType("text/html; charset=UTF-8");	// 设置Content-Type字段值
		PrintWriter out = resp.getWriter();				// 获得PrintWriter对象
		out.println("调用doPost方法 ");
	}
	protected void service(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		resp.setContentType("text/html; charset=UTF-8");	// 设置Content-Type字段值
		PrintWriter out = resp.getWriter();				// 获得PrintWriter对象
		out.println("调用service方法 ");
		super.service(req, resp);
	}
}

修改配置文件WebRoot\WEB-INF\web.xml，</web-app>节点之前插入下列代码, 部署测试(Tomcat控制台)

3. 测试doGet和doPost方法

在cn.duzhaojiang.servlet包创建TestGetPost01.java

package cn.duzhaojiang.servlet;

WebRoot\GetForm01.jsp

WebRoot\PostForm01.jsp

修改配置文件WebRoot\WEB-INF\web.xml，</web-app>节点之前插入下列代码

4. 过滤器测试

cn.duzhaojiang.filter HelloFilter

修改配置文件WebRoot\WEB-INF\web.xml，</web-app>节点之前插入下列代码, 部署测试(Tomcat控制台输出:执行过滤), 本小节测试完成后注释掉本段配置。

5. IP地址过滤器

获取客户端远程ip地址, getRemoteIP01.jsp

cn.duzhaojiang.filter, IPFilter01

package cn.duzhaojiang.filter;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;

import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class IPFilter01 implements Filter {
	protected FilterConfig filterConfig;
	protected String ip;
	
	public void init(FilterConfig filterConfig) throws ServletException {
		this.filterConfig = filterConfig; //设置属性filterConfig
		this.ip = this.filterConfig.getInitParameter("ip"); //获得初始化参数ip
	}
	
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		String remoteIP = request.getRemoteAddr(); //获得客户ip
		if(remoteIP.equals(ip)){ //判断ip是否被禁止
			response.setContentType("text/html; charset=gbk");//设置Content-Type字段值
			PrintWriter out = response.getWriter(); //获得输出流
			out.println("该IP地址被禁止访问，请联系管理员!"); //输出不能访问信息
		}else{
			chain.doFilter(request,response); //向下传递
		}
	}
	
	public void destroy() {
	}
}

修改配置文件WebRoot\WEB-INF\web.xml，</web-app>节点之前插入下列代码, 部署测试(浏览器输出：该IP地址被禁止访问，请联系管理员!), 本小节测试完成后注释掉本段配置。

6. 上下文监听器

json: TestServletContextListener01

修改配置文件WebRoot\WEB-INF\web.xml，</web-app>节点之前插入下列代码, (Tomcat控制台查看，重新部署项目)，本小节测试完成后注释掉本段配置。

实训题. 用户登录、在线用户列表

(1) cn.duzhaojiang.listener OnlineUserListener01.java

package cn.duzhaojiang.listener;

import java.util.ArrayList;

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.http.HttpSessionAttributeListener;
import javax.servlet.http.HttpSessionBindingEvent;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;

public class OnlineUserListener01 implements
	ServletContextListener,HttpSessionListener,HttpSessionAttributeListener{
	private ServletContext application = null ;	// 声明一个ServletContext对象
	
	public void contextInitialized(ServletContextEvent sce) { //ServletContext创建时调用该方法
		ArrayList<String> allUser = new ArrayList<String>();//储存所用用户名
		application = sce.getServletContext();//获得当前application对象
		application.setAttribute("allUser", allUser);//设置到application范围
	}
	
	public void contextDestroyed(ServletContextEvent sce) {//ServletContext销毁时调用该方法
	}
	
	public void sessionCreated(HttpSessionEvent se) {//session创建时调用该方法
	}
	
	public void sessionDestroyed(HttpSessionEvent se) {//session销毁时调用该方法
		//获得当前所有的用户
		ArrayList<String> allUser = (ArrayList<String>) application.getAttribute("allUser");
		String user = (String)se.getSession().getAttribute("username");//获得删除的用户
		allUser.remove(user);//删除该用户
		application.setAttribute("allUser", allUser);//重新设置到application范围中
	}
	
	public void attributeAdded(HttpSessionBindingEvent se) {//session范围属性添加时调用
		//获得当前所有的用户
		ArrayList<String> allUser = (ArrayList<String>) application.getAttribute("allUser");
		//获得添加的用户
		String user = (String) se.getValue();
		//添加到所有用户中
		allUser.add(user);
		//重新设置到application范围中
		application.setAttribute("allUser", allUser);
	}
	
	public void attributeRemoved(HttpSessionBindingEvent se) {//session范围属性移除时调用
	}
	
	public void attributeReplaced(HttpSessionBindingEvent se) {//session范围属性替换时调用
	}
}

(2) 登录页面(测试入口) WebRoot\LoginForm01.jsp

(3) 登录判断页面: WebRoot\LoginConf01.jsp

(4) 用户列表页: WebRoot\UserList01.jsp, 需要face.gif图像

(5) 用户注销页: WebRoot\LoginOut01.jsp

(6) 修改配置文件WebRoot\WEB-INF\web.xml，</web-app>节点之前插入下列代码，本小节测试完成后注释掉本段配置。

上机题1. 学生注册并显示(使用servlet)

cn.duzhaojiang.servlet PrintStudentServlet01.java

package cn.duzhaojiang.servlet;

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 PrintStudentServlet01 extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		request.setCharacterEncoding("gbk");
		response.setCharacterEncoding("gbk");
		String stuNO = request.getParameter("stuNO");
		String stuName = request.getParameter("stuName");
		String age = request.getParameter("age");
		String sex = request.getParameter("sex");
		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>显示学生信息</TITLE></HEAD>");
		out.println(" <BODY>");
		out.println("学生学号：" + stuNO + "");
		out.println("学生姓名：" + stuName + "");
		out.println("学生年龄：" + age + "");
		out.println("学生性别：" + sex + "");
		out.println(" </BODY>");
		out.println("</HTML>");
		out.flush();
		out.close();
	}

public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request, response);
	}
}

测试入口页面jsp: UserInput01.jsp

修改配置文件WebRoot\WEB-INF\web.xml，</web-app>节点之前插入下列代码

上机题2. 用户信息输入并重定向(使用servlet，输入：李、杜、其他)

jsp: test_du.jsp

jsp: test_li.jsp

cn.duzhaojiang.servlet: RedirectServlet01.java

测试入口页面jsp: UserInput01.jsp

修改配置文件WebRoot\WEB-INF\web.xml，</web-app>节点之前插入下列代码

上机题3. 用户登录、验证(使用servlet)

cn.duzhaojiang.servlet: LoginConfServlet01.java

**************测试入口页面: WebRoot\LoginForm01_2.jsp

修改配置文件WebRoot\WEB-INF\web.xml，</web-app>节点之前插入下列代码

上机题4. 学生注册、保存并显示(使用servlet)

4.1 cn.duzhaojiang.bean: Student_01

4.2 cn.duzhaojiang.dao: StudentDAO_01.java

4.3 cn.duzhaojiang.util: DBConnection.java

package cn.duzhaojiang.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class DBConnection {
		
	private static final String DBDRIVER = "com.mysql.jdbc.Driver" ;			//驱动类类名
    private static final String DBURL = "jdbc:mysql://localhost:3306/javaweb04";	//连接URL
    private static final String DBUSER = "root" ;								//数据库用户名
    private static final String DBPASSWORD = "6337925";							//数据库密码

public static Connection getConnection(){
		Connection conn = null;													//声明一个连接对象
		try {
			Class.forName(DBDRIVER);											//注册驱动
			conn = DriverManager.getConnection(DBURL,DBUSER,DBPASSWORD);		//获得连接对象
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return conn;
	}

public static void close(Connection conn) {
		if(conn != null) {				//如果conn连接对象不为空
			try {
				conn.close();			//关闭conn连接对象对象
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}
	
	public static void close(PreparedStatement pstmt) {
		if(pstmt != null) {				//如果pstmt预处理对象不为空
			try {
				pstmt.close();			//关闭pstmt预处理对象
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}
	
	public static void close(ResultSet rs) {
		if(rs != null) {				//如果rs结果集对象不为null
			try {
				rs.close();				//关闭rs结果集对象
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}
}

4.4 cn.duzhaojiang.factory: StudentDAOFactory_01.java

4.5 cn.duzhaojiang.factory: StudentDAOImpl_01.java

package cn.duzhaojiang.impl;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import cn.duzhaojiang.bean.Student_01;
import cn.duzhaojiang.dao.StudentDAO_01;
import cn.duzhaojiang.util.DBConnection;

public class StudentDAOImpl_01 implements StudentDAO_01 {
	//实现添加学生的方法
	public void addStudent(Student_01 student) {
		Connection conn = DBConnection.getConnection();	//获得连接对象
		String addSQL = "insert into student(stuNO,stuName,age,sex) values(?,?,?,?)";
		PreparedStatement pstmt = null;					//声明预处理对象
		try {
			pstmt = conn.prepareStatement(addSQL);		//获得预处理对象并赋值
			pstmt.setString(1, student.getStuNO());		//设置第一个参数
			pstmt.setString(2, student.getStuName());	//设置第二个参数
			pstmt.setInt(3, student.getAge());			//设置第三个参数
			pstmt.setString(4, student.getSex());	//设置第四个参数
			pstmt.executeUpdate();								//执行更新
		} catch (SQLException e) {
			e.printStackTrace();
		} finally{
			DBConnection.close(pstmt);							//关闭预处理对象
			DBConnection.close(conn);							//关闭连接对象
		}
	}
	
	//实现更新学生的方法
	public void updateStudent(Student_01 student) {
		Connection conn = DBConnection.getConnection();	//获得连接对象
		String updateSQL = "update student set stuName = ?,age = ?,sex = ? where stuNo = ?";
		PreparedStatement pstmt = null;					//声明预处理对象
		try {
			pstmt = conn.prepareStatement(updateSQL);	//获得预处理对象并赋值
			pstmt.setString(1, student.getStuName());	//设置第一个参数
			pstmt.setInt(2, student.getAge());			//设置第二个参数
			pstmt.setString(3, student.getSex());		//设置第三个参数
			pstmt.setString(4, student.getStuNO());		//设置第四个参数
			pstmt.executeUpdate();						//执行更新
		} catch (SQLException e) {
			e.printStackTrace();
		} finally{
			DBConnection.close(pstmt);						//关闭预处理对象
			DBConnection.close(conn);						//关闭连接对象
		}
	}
	
	//实现删除学生的方法
	public void deleteStudent(String stuNO) {
		Connection conn = DBConnection.getConnection();	//获得连接对象
		String deleteSQL = "delete from student where stuNO=?";
		PreparedStatement pstmt = null;					//声明预处理对象
		try {
			pstmt = conn.prepareStatement(deleteSQL);	//获得预处理对象并赋值
			pstmt.setString(1, stuNO);					//设置第一个个参数
			pstmt.executeUpdate();						//执行更新
		} catch (SQLException e) {
			e.printStackTrace();
		} finally{
			DBConnection.close(pstmt);					//关闭预处理对象
			DBConnection.close(conn);					//关闭连接对象
		}
	}
	
	//实现查询学生的方法
	public List<Student_01> findAllStudent() {
		Connection conn = DBConnection.getConnection();	//获得连接对象
		String selectSQL = "select * from student";
		PreparedStatement pstmt = null;					//声明预处理对象
		List<Student_01> studentList = new ArrayList<Student_01>();
		try {
			pstmt = conn.prepareStatement(selectSQL);	//获得预处理对象并赋值
			ResultSet rs = pstmt.executeQuery();		//执行查询
			while(rs.next()) {
				Student_01 student = new Student_01();		//实例化
				student.setStuNO(rs.getString(1));
				student.setStuName(rs.getString(2));
				student.setAge(rs.getInt(3));
				student.setSex(rs.getString(4));
				studentList.add(student);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} finally{
			DBConnection.close(pstmt);						//关闭预处理对象
			DBConnection.close(conn);						//关闭连接对象
		}
		return studentList;									//返回查询到的所有学生
	}
	
	public Student_01 findStudentByNo(String stuNO) {
		Connection conn = DBConnection.getConnection();	//获得连接对象
		String selectSQL = "select * from student where stuNO = ?";
		PreparedStatement pstmt = null;					//声明预处理对象
		Student_01 student = new Student_01();				//实例化
		try {
			pstmt = conn.prepareStatement(selectSQL);	//获得预处理对象并赋值
			pstmt.setString(1, stuNO);					//设置参数
			ResultSet rs = pstmt.executeQuery();		//执行查询
			if(rs.next()) {
				student.setStuNO(rs.getString(1));
				student.setStuName(rs.getString(2));
				student.setAge(rs.getInt(3));
				student.setSex(rs.getString(4));
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} finally{
			DBConnection.close(pstmt);							//关闭预处理对象
			DBConnection.close(conn);							//关闭连接对象
		}
		return student;
	}
}

4.6 cn.duzhaojiang.servlet: SaveStudentServlet01.java

package cn.duzhaojiang.servlet;

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;

import cn.duzhaojiang.bean.Student_01;
import cn.duzhaojiang.dao.StudentDAO_01;
import cn.duzhaojiang.factory.StudentDAOFactory_01;

public class SaveStudentServlet01 extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		request.setCharacterEncoding("gbk");
		response.setCharacterEncoding("gbk");
		String stuNO = request.getParameter("stuNO");
		String stuName = request.getParameter("stuName");
		int age = Integer.parseInt(request.getParameter("age"));
		String sex = request.getParameter("sex");
		//保存到数据库
		Student_01 stu = new Student_01();
		stu.setStuNO(stuNO);
		stu.setStuName(stuName);
		stu.setAge(age);
		stu.setSex(sex);
		StudentDAO_01 stuDAO = StudentDAOFactory_01.getStudentDAOInstance();
		stuDAO.addStudent(stu);
		//打印
		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>显示学生信息</TITLE></HEAD>");
		out.println(" <BODY>");
		out.println("学生学号：" + stuNO + "");
		out.println("学生姓名：" + stuName + "");
		out.println("学生年龄：" + age + "");
		out.println("学生性别：" + sex + "");
		out.println(" </BODY>");
		out.println("</HTML>");
		out.flush();
		out.close();
	}

public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request, response);
	}
}

4.7 测试入口[输入学生信息]: WebRoot\StudentForm01_2.jsp

4.8 显示所有学生: WebRoot\ShowStudentList01.jsp

<%@page language="java" pageEncoding="gbk"%>
<%@page import="java.util.List"%>
<%@page import="cn.duzhaojiang.dao.StudentDAO_01"%>
<%@page import="cn.duzhaojiang.factory.StudentDAOFactory_01"%>
<%@page import="cn.duzhaojiang.bean.Student_01"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt"%>
<html>
<head>
	<title>学生列表</title> 
</head>
<body>
	<%
		//通过DAO工厂类获得DAO实现类实例
		StudentDAO_01 studentDAO = StudentDAOFactory_01.getStudentDAOInstance();
		//查找所有学生记录 
		List<Student_01> studentList = studentDAO.findAllStudent();
		//将所有记录保存到page范围 
		pageContext.setAttribute("studentList",studentList);
	%>
	<h1>学生列表(杜兆将老师整理)</h1>
	<hr />
	<table width="700" border="1">
		<tr>
			<td>学生学号</td>
			<td>学生姓名</td>
			<td>学生年龄</td>
			<td>学生性别</td>
		</tr>
		<c:forEach var="student" items="${pageScope.studentList}"><%-- 循环输出学生信息 --%>
			<tr>
				<td>${student.stuNO }</td>
				<td>${student.stuName }</td>
				<td>${student.age }</td>
				<td>${student.sex }</td>
			</tr>
		</c:forEach>
	</table>
	<hr/>
	<a href="/01JavaWeb05">返回本章目录</a>
</body>
</html>

4.9 修改配置文件WebRoot\WEB-INF\web.xml，</web-app>节点之前插入下列代码

上机题5. 用户发言————非法文字过滤器(Filter)

5.1 非法文字过滤器(使用Filter，过滤：你妈的)之定义: 在cn.duzhaojiang.filter包下创建CharacterFilter01.java

package cn.duzhaojiang.filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

public class CharFilter01 implements Filter{
	//初始化方法
	public void init(FilterConfig filterConfig) throws ServletException {
		System.out.println("非法文字过滤器.初始化");
	}
	//过滤方法
	public void doFilter(ServletRequest req, ServletResponse res,
			FilterChain chain) throws IOException, ServletException {
		HttpServletRequest request = (HttpServletRequest)req;
		//设置参数编码格式
		request.setCharacterEncoding("gbk");
		//接受聊天内容
		String charContent = request.getParameter("charContent");
		if(charContent != null) {
			if(charContent.indexOf("你妈的")== -1) {
				chain.doFilter(req, res);
			} else {
				request.getRequestDispatcher("SendFailure01.jsp").forward(req, res);
			}
		} else {
			chain.doFilter(req, res);
		}
	}
	//销毁方法
	public void destroy() {
		System.out.println("非法文字过滤器.销毁");
	}
}

5.2 入口网页：用户言论输入网页 WebRoot\CharForm01.jsp

5.3 显示用户言论网页(发言成功) WebRoot\ShowContent01.jsp

5.4 显示用户言论网页(发言失败) WebRoot\SendFailure01.jsp

5.5 修改配置文件WebRoot\WEB-INF\web.xml，</web-app>节点之前插入下列代码

上机题6. 字符编码过滤器之定义与配置

6.1 字符编码过滤器之定义: 在cn.duzhaojiang.filter包下创建CharacterFilter01.java

6.2 修改配置文件WebRoot\WEB-INF\web.xml，</web-app>节点之前插入下列代码，本小节测试完成后注释掉本段配置。

上机题7. 登陆验证过滤器之定义与配置

登陆验证过滤器之定义: 在cn.duzhaojiang.filter包创建LoginFilter01.java

package cn.duzhaojiang.filter;

import java.io.IOException;

public class LoginFilter01 implements Filter{
	//初始化方法
	public void init(FilterConfig filterConfig) throws ServletException {
		System.out.println("登陆验证过滤器初始化");
	}
	//过滤方法
	public void doFilter(ServletRequest req, ServletResponse res,
			FilterChain chain) throws IOException, ServletException {
		HttpServletRequest request = (HttpServletRequest)req;
		//获得session对象
		HttpSession session = request.getSession();
		String login = (String) session.getAttribute("username");
		//如果是登陆判断页面，不用进行过滤检查
		if("/01JavaWeb05/LoginConf01.jsp".equals(request.getRequestURI())) {
			chain.doFilter(req, res);
		} else {
			//判断用户是否进行了登陆，如果进行了登陆才能继续操作，否则跳转到登陆页面
			if(login == null || "".equals(login)){
				request.getRequestDispatcher("LoginForm01.jsp").forward(req, res);
			} else {
				chain.doFilter(req, res);
			}
		}
	}
	//销毁方法
	public void destroy() {
		System.out.println("登陆验证过滤器销毁");
	}
}

修改配置文件WebRoot\WEB-INF\web.xml，</web-app>节点之前插入下列代码，本小节测试完成后注释掉本段配置。

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