没有美化,没有格式,没有样式
1.JSP登陆注册
将用户注册的信息保存在application对象中,用于登录时的验证。
首页如下:
如果未登录,在 session 中找不到 currentUser 的值,则直接跳转到其他页面。
<%@ page language="java" 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>
<!-- 用于验证是否登录,如果没有登陆则不能访问该页面,并跳转到登录页面 -->
<%
Object obj = session.getAttribute("currentUser");
if (obj == null) {
response.sendRedirect("login.jsp");
}
%>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
</head>
<body>
<h1>这是一个首页 !</h1>
</body>
</html>
注册页面如下:
<%@ page language="java" 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>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="operation.jsp" method="post">
<input type="hidden" name="sub_type" value="reg" />
<input type="text" name="username" placeholder="输入用户名" />
<input type="password" name="password" placeholder="输入密码" />
<input type="password" name="password1" placeholder="确认密码" />
<input type="submit" value="注册" /><a href="login.jsp">返回登陆</a>
</form>
</body>
</html>
登录页面如下:
<%@ page language="java" 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>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="operation.jsp" method="post">
<input type="hidden" name="sub_type" value="log" />
<input type="text" name="username" placeholder="输入用户名" />
<input type="password" name="password" placeholder="输入密码" />
<input type="submit" value="登录" /><a href="register.jsp">注册新用户</a>
</form>
</body>
</html>
用户类,用于存放用户信息:
仅有用户名和代码两个属性。
package test;
public class User {
private String username;
private String 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;
}
@Override
public String toString() {
return "User [username=" + username + ", password=" + password + "]";
}
}
逻辑控制页面如下:
首先根据给登录页面和注册页面设置的隐藏的 sub_type 属性判断是登录还是注册,然后进行相应的判断。
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="test.User"%>
<%
//获取请求的信息
String sub_type = request.getParameter("sub_type");
String username = request.getParameter("username");
String password = request.getParameter("password");
String password1 = request.getParameter("password1");
//判断是登录页面还是注册页面
if("reg".equals(sub_type)) {
if (!password.equals(password1)) {
out.print("两次输入的密码不一致 !");
} else {
Object obj = application.getAttribute(username);
if (obj != null) { //用传来的用户名找用户,如果不为空则用户已存在
out.print("用户名已经存在 !");
} else {
User user = new User(); //实例化一个用户并设置信息
user.setUsername(username);
user.setPassword(password);
application.setAttribute(username, user);
out.print("注册成功 !");
}
}
}
if("log".equals(sub_type)) {
Object obj = application.getAttribute(username);
if(obj!=null) {
User u = (User)obj;//将获取到的对象强转型,然后获取信息进行判断
if(password.equals(u.getPassword())) {
session.setAttribute("currentUser", u);
response.sendRedirect("index.jsp");
} else {
out.print("密码不对啊 !");
}
} else {
out.print("用户名不存在 !");
}
}
out.print("<br>");
out.print("<a href='login.jsp'>跳转登陆</a>");
%>
2.记事本:
在用户登录注册的基础上进行修改,登陆后的用户可以在记事本留言,其他用户登录后可以看到,按照时间倒序排序,可以看到用户名,留言信息,留言时间。
添加一个留言类, Says类,有 用户,留言时间,留言内容三个属性。
主页如下,除了判断登录用户,设置 utf-8 之外,还有注意输出的时候先倒序,遍历输出之后再次倒序。
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8" import="test.Says,test.User,java.util.*"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<%
Object obj1 = session.getAttribute("currentUser");
if (obj1 == null) {
response.sendRedirect("denglu.jsp");
}
%>
<%
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
%>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="chuli.jsp" method="post">
<input type="hidden" name="sub_type" value="tex" />
<textarea rows="4" cols="12" name="text"></textarea>
<input type="submit" value="提交">
</form>
<%
Object obj=application.getAttribute("s");
if(obj!=null){
ArrayList<Says> list=(ArrayList)obj;
Collections.reverse(list);//倒序,以保证后写入的内容排在上边
for(Says say : list){
out.print(say.getUname()+" "+"|"+" ");
out.print(say.getDate()+"<br>");
out.print(say.getSays()+"<br>");
}
Collections.reverse(list);//再次倒序,否则输出的后会出问题
}
%>
</body>
</html>
注册:
<%@ page language="java" 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>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="chuli.jsp" method="post">
<input type="hidden" name="sub_type" value="reg" />
<input type="text" name="username" placeholder="输入用户名" />
<input type="password" name="password" placeholder="输入密码" />
<input type="password" name="password1" placeholder="确认密码" />
<input type="submit" value="注册" /><a href="denglu.jsp">返回登陆</a>
</form>
</body>
</html>
登录:
<%@ page language="java" 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>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="chuli.jsp" method="post">
<input type="hidden" name="sub_type" value="log" />
<input type="text" name="username" placeholder="输入用户名" />
<input type="password" name="password" placeholder="输入密码" />
<input type="submit" value="登录" /><a href="zhuce.jsp">注册新用户</a>
</form>
</body>
</html>
用户类:
package test;
public class User {
private String username;
private String 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;
}
}
留言类:
package test;
import java.util.Date;
public class Says {
private String uname;//暂无用
private String date;
private String says;
public String getUname() {
return uname;
}
public void setUname(String uname) {
this.uname = uname;
}
public String getDate() {
return date;
}
public void setDate(String date) {
this.date = date;
}
public String getSays() {
return says;
}
public void setSays(String says) {
this.says = says;
}
@Override
public String toString() {
return "Says [uname=" + uname + ", date=" + date + ", says=" + says + "]";
}
}
逻辑处理:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8" import="test.Says,test.User,java.util.*"%>
<%
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
%>
<%
String sub_type = request.getParameter("sub_type");
String password = request.getParameter("password");
String password1 = request.getParameter("password1");
Says says=new Says();
if("reg".equals(sub_type)) {
String username = request.getParameter("username");
System.out.println(username);
if (!password.equals(password1)) {
out.print("两次输入的密码不一致 !");
} else {
Object obj = application.getAttribute(username);
if (obj != null) {
out.print("用户名已经存在 !");
} else {
User user = new User();
user.setUsername(username);
user.setPassword(password);
application.setAttribute(username, user);
out.print("注册成功 !");
}
}
out.print("<br>");
out.print("<a href='denglu.jsp'>跳转登陆</a>");
}
if("log".equals(sub_type)) {
String username = request.getParameter("username");
System.out.println(username);
application.setAttribute("name",username);
Object obj = application.getAttribute(username);
if(obj!=null) {
User u = (User)obj;
if(password.equals(u.getPassword())) {
session.setAttribute("currentUser", u);
//String name=u.getUsername();
//application.setAttribute("name",name);
response.sendRedirect("main.jsp");
} else {
out.print("密码不对啊 !");
}
} else {
out.print("用户名不存在 !");
}
out.print("<br>");
out.print("<a href='denglu.jsp'>跳转登陆</a>");
}
if("tex".equals(sub_type)){
String say = request.getParameter("text");
Date d=new Date();
Object sobj=application.getAttribute("name");//获取用户名
String sname=(String)sobj;
System.out.println(sname);
says.setUname(sname);
says.setSays(say);
says.setDate(d.toLocaleString());
Object obj=application.getAttribute("s");
if(obj==null){
List list =new ArrayList();
list.add(says);
application.setAttribute("s",list);
}else{
List<Says> list=(List)obj;
list.add(says);
application.setAttribute("s",list);
}
response.sendRedirect("main.jsp");
}
%>