《从零开始学Java Web开发》习题
第5章 JSP内置对象
二、上机题
1、使用session和application对象实现一个网站计数器。
/*session对象实现*/
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
<%! int count=0; %>
<%
String scount;
request.getSession(true);
if(session.isNew()){
count++;
scount=String.valueOf(count);
session.putValue("scount", scount);
}
out.print("您是本站第");
out.print(session.getValue("scount"));
out.print("位访客！");
session.invalidate();
%>
/*application对象实现*/
<%@ page language="java" contentType="text/html; charset=gb2312"
pageEncoding="gb2312"%>
<%@ page import="java.util.*,javax.servlet.*" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<%
Object oCount=application.getAttribute("count");
Integer count=null;
if(oCount==null){
count=new Integer(1);
application.setAttribute("count",count);
}else{
count=(Integer)application.getAttribute("count");
count=new Integer(count.intValue()+1);
application.setAttribute("count",count);
}
%>
您是本站第<%=count.intValue() %>位访客！
2、使用request对象实现一个接受用户登录信息的JSP页面
/* index.jsp*/
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <form action="login.jsp" method="post"> 用户名：<input id="name" name="name" type="text"/></br> 密码：<input id="password" name="password" type="password"/></br> <input type="submit" value="登陆"/><input type="reset" value="重置"/> </form>
/*login.jsp*/
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
<%
String username=request.getParameter("name");
String userpassword=request.getParameter("password");
if(username.equals("lcxia")&&userpassword.equals("111")){
out.print("登陆成功！！(￣▽￣)");
}else{
out.print("用户名或密码错误，请重新登陆！");
}
%>
3、使用response对象，实现5秒自动刷新功能
<%@page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
<%@page import="java.util.*" %>
<%
response.setHeader("Refresh", "5");
out.print(new Date().toString());
%>
第7章 JSP与JDBC
二、上机题
2、使用可更新数据集对数据库进行记录的插入和删除操作。
/* index.jsp*/
<%@ page language="java" import="java.sql.*" import="javax.sql.*" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <title>this is test file!</title> </head> <h1>数据库插入和删除测试</h1> <body> <form action="insert.jsp" method="post"> 用户名:<input name="name" type="text"><br> 密码:<input name="password" type="password"><br> <input name="submit" type="submit" value="插入"> </form> <a href="search.jsp">点击此处进入数据库查询页面</a> </body> </html>
/* insert.jsp*/
<%@ page language="java" import="java.sql.*" import="javax.sql.*"
contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
<%
try {
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/test", "root", "1234");
PreparedStatement pstate = conn.prepareStatement(
"select * from user", ResultSet.TYPE_SCROLL_SENSITIVE,
ResultSet.CONCUR_UPDATABLE);
ResultSet rs = pstate.executeQuery();
rs.moveToInsertRow();
rs.updateString(2, request.getParameter("name"));
rs.updateString(3, request.getParameter("password"));
rs.insertRow();
out.print("用户注册成功！");
} catch (Exception e) {
out.print("用户注册失败！");
out.print(e);
}
%>
/* search.jsp*/
<%@ page language="java" import="java.sql.*" import="javax.sql.*" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<html>
<title>数据库查询页面</title>
<h4>数据库查询</h4>>
<%
try{
Class.forName("com.mysql.jdbc.Driver");
Connection conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","1234");
PreparedStatement pstate=conn.prepareStatement("select * from user;");
ResultSet rs=pstate.executeQuery();
out.print("<table border=1>");
out.print("<tr><td></td><td>用户名</td><td>密码</td></tr>");
int i=0;
while(rs.next()){
out.print("<tr><td>");
out.print(++i);
out.print(".");
out.print("</td><td>");
out.print(rs.getString(2));
out.print("</td><td>");
out.print(rs.getString(3));
out.print("</td></tr>");
}
out.print("</table>");
}catch(Exception e){
out.print(e);
}
%>
<form action="delete.jsp" method="post">
请输入要删除的序号：<input type="text" name="number"><br>
<input type="submit" value="删除">
</form>>
</html>
/* delete.jsp*/
<%@ page language="java" import="java.sql.*" import="javax.sql.*"
contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
<%
try {
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/test", "root", "1234");
PreparedStatement pstate = conn.prepareStatement(
"select * from user", ResultSet.TYPE_SCROLL_SENSITIVE,
ResultSet.CONCUR_UPDATABLE);
ResultSet rs = pstate.executeQuery();
rs.absolute(Integer.valueOf(request.getParameter("number")));
rs.deleteRow();
} catch (Exception e) {
out.print("数据删除失败！");
out.print(e);
}
%>
<a href="search.jsp">返回查询页面</a>
3、在Tomcat服务器中配置并配置并使用MySQL数据库的数据库链接池。
//没有使用书中的方法，使用的是proxool技术
//1、下载proxool 地址：http://proxool.sourceforge.net
//2、解压缩proxool-0.9.0RC2.zip，拷贝lib/proxool-0.9.0RC2.jar到web-info/lib；拷贝jdbc驱动到web-info/lib
//3、在web-info下建立文件：proxool.xml
/* proxool.xml*/
<?xml version="1.0" encoding="UTF-8"?> <something-else-entirely> <proxool> <alias>Develop</alias> <driver-url>jdbc:mysql://localhost/test</driver-url> <driver-class>org.gjt.mm.mysql.Driver</driver-class> <driver-properties> <property name="user" value="root" /> <property name="password" value="1234" /> </driver-properties> <maximum-connection-count>10</maximum-connection-count> <house-keeping-test-sql>select CURRENT_DATE</house-keeping-test-sql> </proxool> </something-else-entirely>
//4、在web.xml里新增如下：
/* web.xml*/
<servlet> <servlet-name>proxoolServletConfigurator</servlet-name> <servlet-class>org.logicalcobwebs.proxool.configuration.ServletConfigurator</servlet-class> <init-param> <param-name>xmlFile</param-name> <param-value>WEB-INF/proxool.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet> <servlet-name>Admin</servlet-name> <servlet-class>org.logicalcobwebs.proxool.admin.servlet.AdminServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>Admin</servlet-name> <url-pattern>/admin</url-pattern> </servlet-mapping>
//5、在调用数据库连接代码：
Class.forName("org.logicalcobwebs.proxool.ProxoolDriver");
Connection conn = DriverManager.getConnection("proxool.Develop");
//6、利用proxool监控工具查看数据库运行状态。地址：./admin
第8章 Servlet编程
二、上机题
1、使用Servlet实现用户注册系统。
/*ServletDemo.java*/
package com.inoue.test;
import java.io.IOException;
import java.sql.*;
import javax.sql.*;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ServletDemo extends HttpServlet {
public void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException
{
response.setContentType("text/html;charset=utf-8");
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 Demo</TITLE></HEAD>");
out.println(" <BODY>");
try{
Class.forName("com.mysql.jdbc.Driver");
Connection conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","1234");
Statement state=conn.createStatement();
int result=state.executeUpdate("insert into user(name,password) values('"+request.getParameter("name")+"','"+request.getParameter("password")+"')");
if(result==1){
out.print("注册成功!");
}else{
out.print("注册失败！");
}
}catch(Exception e){
out.print(e);
}
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
}
/*index.jsp*/
<%@ page language="java" import="java.sql.*" import="javax.sql.*" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <title>this is login test !!</title> </head> <body> <form action="ServletDemo" method="post"> 用户名：<input name="name" type="text"><br> 密码：<input name="password" type="password"><br> <input type="submit" value="注册"> </form> </body> </html>
/*web.xml*/
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1"> <display-name>WebTest</display-name> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> <servlet> <servlet-name>ServletDemo</servlet-name> <servlet-class>com.inoue.test.ServletDemo</servlet-class> </servlet> <servlet-mapping> <servlet-name>ServletDemo</servlet-name> <url-pattern>/ServletDemo</url-pattern> </servlet-mapping> </web-app>