jsp通讯录登录与添加
记录一下Javaee的学习
首先讲一下什么是jsp?
万事先百度。
JSP全名为Java ServerPages，中文名叫java服务器页面，其根本是一个简化的Servlet设计，它是由Sun Microsystems公司倡导、许多公司参与一起建立的一种动态网页技术标准。JSP技术有点类似ASP技术，它是在传统的网页HTML（标准通用标记语言的子集）文件(*.htm,*.html)中插入Java程序段(Scriptlet)和JSP标记(tag)，从而形成JSP文件，后缀名为(*.jsp)。 用JSP开发的Web应用是跨平台的，既能在Linux下运行，也能在其他操作系统上运行。
其实说白了，就是html+java+js+css。sun公司想把java向网页推广的产品，不过确实很成功。
讲一下jsp运行的原理，和设计jsp项目的流程。
login.jsp--->LoginServlet--->LoginService--->jdbcUtil.java--->数据库
不管是jsp还是servlet，当Tomcat服务器开启的时候，tomcat容器都会去加载jsp,说到底最后还是会被jvm编译成一个class文件，jvm认识的java代码会编译成class，不认识的html代码则会被out打印成字符串，留给浏览器解析。其实说到底还是java。
列举到登录验证过程，当用户输入账号和密码，点击提交的时候，form表单则将请求以method(post,get)，账号密码比较重要的数据，一般用post提交，则不会在地址栏显示。此时地址则会改变，比如login.jsp会变成LoginServlet，Servlet做相应逻辑处理，但是做事的还是service，与dao数据库打交道是service，而servlet只是向service要数据。然后servlet通过数据库里的账号和密码验证后，则通过转发或者重定向，跳转到另一个jsp。
因此jsp项目的设计流程是：
表设计--->jdbcUtil-->bean-->service-->jsp-->servlet
一般是先设计数据库，最后再设计servlet，中间大同小异。
废话不多说，直接贴代码。
实现通讯录添加、显示。要求如下：
1） 用户只有登录后才能对通讯录进行添加和查询显示
2） 如果用户没有登录直接访问通讯录维护页面，则提示用户先进行登录，然后点击链接让其跳转至登录页面进行登录。
流程如下：
1） 用户访问登录页面，输入用户名、密码，点击提交，进入servlet验证用户名密码的正确性。
2） 如果验证成功，则跳转至新的jsp页面，显示所有的通讯录信息，并在右上角显示当前登录用户名；如果验证不成功，则跳转至登录页面。
3） 在通讯录显示页面，有一个”添加通讯录”的按钮，点击后进行添加通讯录页面，并进行添加。
4） 退出系统
5） 统计访问人数
环境:myeclipse2014 jdk1.7 mysql tomcat7
mysql数据库表结构
一个用户表(users) 一个用来存储用户好友的表(persons)
users表:
create table users
(
username varchar(10) primary key,
password varchar() not null
)
persons表:
create table persons
(
username varchar(10) references users(username),
id int(20) primary key auto_increment,
name varchar(10) not null,
tel varchar(30),
address varchar(20)
)
login.jsp(登录界面)
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%
String num=(String)application.getAttribute("num");
if(num==null){
//第一次访问
application.setAttribute("num", "1");
}else{
int num_ = Integer.parseInt(num);
num_ +=1;
application.setAttribute("num", String.valueOf(num_));
}
%>
<!DOCTYPE>
<html>
<head>
<base href="<%=basePath%>">
<title>Login</title>
</head>
<body>
<p>网站访问次数,<%=application.getAttribute("num") %></p>
<form action="AddressServlet" method="post">
用户名:<input type="text" id="username" name="username" size="20" required="required"/>
密码:<input type="password" id="password" name="password" size="20" required="required"/>
<input type="hidden" id="type" name="type" value="login"/>
<input type="submit" value="提交">
</form>
</body>
</html>
list.jsp(显示信息界面)
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%@ page import="com.work.bean.Person" %>
<!DOCTYPE>
<html>
<head>
<base href="<%=basePath%>">
<title>list</title>
</head>
<body>
<p>当前在线人数:${userCounts }</p>
<p>正在登录的用户是:<%=request.getAttribute("user") %></p>
<a href="add.jsp">添加通讯录</a>
<div>
<table border="1" style="border-collapse:collapse">
<tr>
<th>用户编号</th>
<th>姓名</th>
<th>手机</th>
<th>地址</th>
</tr>
<%
Object getlists=request.getAttribute("personlists");
ArrayList<Person> personlists=(ArrayList<Person>)getlists;
if(personlists!=null)
{
for(Person p:personlists)
{
%>
<tr>
<td>
<%= p.getId() %>
</td>
<td>
<%= p.getName() %>
</td>
<td>
<%= p.getTel() %>
</td>
<td>
<%= p.getAddress() %>
</td>
</tr>
<%
}
}
else
{%>
<tr>
<td>没有数据</td>
</tr>
<%
}
%>
</table>
</div>
</body>
</html>
add.jsp(通讯录添加好友)
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE>
<html>
<head>
<base href="<%=basePath%>">
<title>add</title>
</head>
<body>
<form action="AddressServlet" method="post">
姓名<input type="text" id="name" name="name" size="20" required="required"/>
手机<input type="text" id="tel" name="tel" size="20" required="required"/>
地址<input type="text" id="address" name="address" size="20" required="required"/>
<input type="hidden" id="type" name="type" value="add">
<input type="submit" value="添加"/>
</form>
</body>
</html>AddressServlet(web层)
package com.work.web;
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 com.work.bean.Person;
import com.work.bean.User;
import com.work.dao.PUtil;
import com.work.service.AddressService;
public class AddressServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String username=request.getParameter("username");
String password=request.getParameter("password");
String name=request.getParameter("name");
String tel=request.getParameter("tel");
String address=request.getParameter("address");
String type=request.getParameter("type");
User user;
Person p;
if(!"".equals(username))
{
user=new User(username,password);
request.setAttribute("user", username);
}
if(!"".equals(type)&&type!=null&&!"".equals(username)&&"login".equals(type))
{
if(AddressService.islogin(username, password))
{
user = new User(username, password);
request.setAttribute("personlists", AddressService.list(username));
//request.setAttribute("adminname", adminname);
request.getSession().setAttribute("user", user);
PUtil.uname=username;
request.getRequestDispatcher("/list.jsp").forward(request, response);
}
else
{
request.getRequestDispatcher("/login.jsp").forward(request, response);
}
}
if(!"".equals(type)&&type!=null&&!"".equals(username)&&"add".equals(type))
{
p=new Person(name, tel, address);
if(AddressService.add(p,PUtil.getUname()))
{
request.setAttribute("user", PUtil.uname);
request.setAttribute("personlists", AddressService.list(PUtil.uname));
request.getRequestDispatcher("/list.jsp").forward(request, response);
}
else
{
request.getRequestDispatcher("/add.jsp").forward(request, response);
}
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
}
}AddressService.java(service层)
package com.work.service;
import java.util.ArrayList;
import com.work.bean.Person;
import com.work.dao.PUtil;
public class AddressService {
//登录验证
public static boolean islogin(String username,String pwd)
{
return PUtil.islogin(username, pwd);
}
//查看通讯录里的好友
public static ArrayList<Person> list(String username)
{
return PUtil.list(username);
}
//添加通讯录好友
public static boolean add(Person p,String username)
{
return PUtil.add(p, username);
}
//添加新用户
public static boolean addUser(String username,String pwd)
{
return PUtil.addUser(username, pwd);
}
}
SessionListener.java(监听器)
package com.work.listener;
import javax.servlet.http.HttpSessionAttributeListener;
import javax.servlet.http.HttpSessionBindingEvent;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;
public class SessionListener implements HttpSessionListener,HttpSessionAttributeListener{
private int userCounts = 0;//在线人数
@Override
public void attributeAdded(HttpSessionBindingEvent be) {
System.out.println("session添加属性"+be.getName()+"--"+be.getValue());
}
@Override
public void attributeRemoved(HttpSessionBindingEvent be) {
System.out.println("session移除属性"+be.getName()+"--"+be.getValue());
}
@Override
public void attributeReplaced(HttpSessionBindingEvent be) {
System.out.println("session替换属性"+be.getName()+"--"+be.getValue());
}
@Override
public void sessionCreated(HttpSessionEvent se) {
userCounts++;
se.getSession().setAttribute("userCounts", userCounts);
System.out.println("新的会话创建===="+se.getSession().getId());
}
@Override
public void sessionDestroyed(HttpSessionEvent se) {
userCounts--;
se.getSession().setAttribute("userCounts", userCounts);
System.out.println("会话销毁===="+se.getSession().getId());
}
}
Afilter.java(过滤器)
package com.work.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;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class Afilter implements Filter {
@Override
public void doFilter(ServletRequest arg0, ServletResponse arg1,
FilterChain arg2) throws IOException, ServletException {
// TODO Auto-generated method stub
HttpServletRequest request=(HttpServletRequest)arg0;
HttpServletResponse response=(HttpServletResponse)arg1;
String currentURL = request.getRequestURI();
String targetURL = currentURL.substring(currentURL.indexOf("/", 1),
currentURL.length());
HttpSession session = request.getSession(false);
if (!"/login.jsp".equals(targetURL)) {// 判断当前页是否是重定向以后的登录页面页面，如果是就不做session的判断，防止出现死循环
if (session == null || session.getAttribute("user") == null) {
// *用户登录以后需手动添加session
System.out.println("request.getContextPath()="
+ request.getContextPath());
response.sendRedirect(request.getContextPath() + "/login.jsp");
// 如果session为空表示用户没有登录就重定向到login.jsp页面
return;
}
}
// 加入filter链继续向下执行
arg2.doFilter(request, response);
}
@Override
public void destroy() {
// TODO Auto-generated method stub
System.out.println("过滤器已经回收...");
}
@Override
public void init(FilterConfig arg0) throws ServletException {
// TODO Auto-generated method stub
System.out.println("过滤器正在过滤...");
}
}
PUtil.java(dao层)
package com.work.dao;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import com.work.bean.Person;
public class PUtil {
static Connection conn;
static PreparedStatement ps;
static ResultSet rs;
static ArrayList<Person> plists;
public static String uname;
private static final String DBDRIVER="com.mysql.jdbc.Driver";
private static String USERNAME="root";
private static String PASSWORD="123456";
private static String URL="jdbc:mysql://localhost:3306/qq";
//添加用户
public static boolean addUser(String username,String pwd)
{
try {
Class.forName(DBDRIVER);
conn=DriverManager.getConnection(URL, USERNAME, PASSWORD);
String sql="insert into users values(?,?)";
ps=conn.prepareStatement(sql);
ps.setString(1, username);
ps.setString(2, pwd);
ps.execute();
return true;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
try {
ps.close();
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return false;
}
//验证用户登录
public static boolean islogin(String username,String pwd)
{
try {
Class.forName(DBDRIVER);
conn=DriverManager.getConnection(URL, USERNAME, PASSWORD);
String sql="select * from users where username=? and password=?";
ps=conn.prepareStatement(sql);
ps.setString(1, username);
ps.setString(2, pwd);
rs=ps.executeQuery();
while(rs.next())
{
if(rs.getString("username").equals(username)&&rs.getString("password").equals(pwd))
{
return true;
}
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
try {
rs.close();
ps.close();
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return false;
}
//查看全部
public static ArrayList<Person> list(String username)
{
Person person;
try {
Class.forName(DBDRIVER);
conn=DriverManager.getConnection(URL, USERNAME, PASSWORD);
String sql="select * from persons where username=?";
ps=conn.prepareStatement(sql);
ps.setString(1, username);
rs=ps.executeQuery();
plists=new ArrayList<>();
while(rs.next())
{
person=new Person(rs.getInt("id"),rs.getString("name"),rs.getString("tel"), rs.getString("address"));
plists.add(person);
}
return plists;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
try {
rs.close();
ps.close();
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return null;
}
//添加通讯录的好友
public static boolean add(Person p,String username)
{
try {
Class.forName(DBDRIVER);
conn=DriverManager.getConnection(URL, USERNAME, PASSWORD);
String sql="insert into persons(username,name,tel,address) values(?,?,?,?)";
ps=conn.prepareStatement(sql);
ps.setString(1,username);
ps.setString(2, p.getName());
ps.setString(3, p.getTel());
ps.setString(4, p.getAddress());
ps.execute();
return true;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
try {
ps.close();
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return false;
}
public static String getUname() {
return uname;
}
public static void setUname(String uname) {
PUtil.uname = uname;
}
}Person.java(bean)
package com.work.bean;
public class Person {
int id;
String name;
String tel;
String address;
public Person() {
}
public Person(int id,String name, String tel, String address) {
this.id=id;
this.name = name;
this.tel = tel;
this.address = address;
}
public Person(String name, String tel, String address) {
this.name = name;
this.tel = tel;
this.address = address;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getTel() {
return tel;
}
public void setTel(String tel) {
this.tel = tel;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
}
User.java(bean)
package com.work.bean;
public class User {
String username;
String password;
public User()
{
}
public User(String username, String password) {
super();
this.username = username;
this.password = password;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
};
}web.xml(配置文件有很严格的顺序要求 filter-->servlet-->listener-->session)
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd">
<web-app>
<filter>
<filter-name>Afilter</filter-name>
<filter-class>com.work.filter.Afilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>utf-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>Afilter</filter-name>
<url-pattern>*.jsp</url-pattern>
</filter-mapping>
<!-- 监听器的配置 (被动执行的,当相关对象的事件发生时执行) -->
<listener>
<listener-class>com.work.listener.SessionListener</listener-class>
</listener>
<servlet>
<servlet-name>AddressServlet</servlet-name>
<servlet-class>com.work.web.AddressServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>AddressServlet</servlet-name>
<url-pattern>/AddressServlet</url-pattern>
</servlet-mapping>
<!-- session时长设置 单位：分-->
<session-config>
<session-timeout>1</session-timeout>
</session-config>
</web-app>
还有mysql jdbc jar 可以去mysql官网下载
