本文实例为大家分享了java用户注册功能，供大家参考，具体内容如下
主页面:
浏览器显示：
代码实现：
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<%@ page language="java" import="java.util.*" pageencoding="utf-8"%>
<html>
<head>
<title>用户信息管理</title>
</head>
<body>
用户注册:<br/>
<!-- 相对路径 -->
<form action="reg" method="post">
姓名:<input type="text" name="name"/><br/>
密码:<input type="password" name="pwd"/><br/>
<input type="submit" value="注册"/>
</form>
<!-- 绝对路径 -->
<a href="/usersweb/reg">查看所有用户</a><!-- get方式:超链接和在url后面添加参数 -->
</body>
</html>
注册功能：
浏览器显示：
1)注册成功：
2)注册失败：
代码实现:
package cn.hncu.user.servlet;
import java.io.ioexception;
import java.io.printwriter;
import java.util.list;
import javax.servlet.servletexception;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;
import cn.hncu.user.dao.userdao;
import cn.hncu.user.dao.userdaoimpl;
import cn.hncu.user.domain.user;
public class regservlet extends httpservlet {
//注入
userdao dao=new userdaoimpl();
public void doget(httpservletrequest request, httpservletresponse response)
throws servletexception, ioexception {
list<user> users=dao.queryallusers();
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>注册结果页面</title></head>");
out.println(" <body>");
out.println("<table cellspacing=0 border=1px><tr><th>操作</th><th>姓名</th></tr>");
for(user u:users){
out.println("<tr><td><a href='/usersweb/del?id="+u.getid()+"'>删除</a></th>");
out.println("<th>"+u.getname()+"</th></tr>");
}
out.println("</table>");
out.println(" </body>");
out.println("</html>");
out.flush();
out.close();
}
public void dopost(httpservletrequest request, httpservletresponse response)
throws servletexception, ioexception {
request.setcharacterencoding("utf-8");
string name=request.getparameter("name");
string pwd=request.getparameter("pwd");
user user=new user();
user.setname(name);
user.setpwd(pwd);
boolean boo=dao.reg(user);
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>注册结果页面</title></head>");
out.println(" <body>");
if(boo){
out.println("恭喜您("+name+")注册成功了...");
}else{
out.println("您("+name+")注册失败了...<br/>用户名已存在,请换一个注册");
}
out.println("<a href='javascript:history.go(-1)'>返回</a>");
out.println(" </body>");
out.println("</html>");
out.flush();
out.close();
}
}
查看所有用户功能:
浏览器显示：
代码实现： regservlet类的doget方法实现
删除操作功能：删除成功会重定向到主页面
代码实现：
package cn.hncu.user.servlet;
import java.io.ioexception;
import javax.servlet.servletexception;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;
import cn.hncu.user.dao.userdao;
import cn.hncu.user.dao.userdaoimpl;
public class delservlet extends httpservlet {
public void doget(httpservletrequest request, httpservletresponse response)
throws servletexception, ioexception {
string id=request.getparameter("id");
// system.out.println("del-id:"+id);
userdao dao=new userdaoimpl();
dao.deluser(id);
//转到主页--重定向
response.sendredirect("/usersweb/index.jsp");
}
public void dopost(httpservletrequest request, httpservletresponse response)
throws servletexception, ioexception {
doget(request,response);
}
}
配置文件：
<?xml version="1.0" encoding="utf-8"?> <web-app version="3.0" 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_3_0.xsd"> <display-name></display-name> <servlet> <servlet-name>regservlet</servlet-name> <servlet-class>cn.hncu.user.servlet.regservlet</servlet-class> </servlet> <servlet> <servlet-name>delservlet</servlet-name> <servlet-class>cn.hncu.user.servlet.delservlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>regservlet</servlet-name> <url-pattern>/reg</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>delservlet</servlet-name> <url-pattern>/del</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> </web-app>
domain包的user对象
package cn.hncu.user.domain;
public class user {
private string id;
private string name;
private string pwd;
public string getname() {
return name;
}
public void setname(string name) {
this.name = name;
}
public string getpwd() {
return pwd;
}
public void setpwd(string pwd) {
this.pwd = pwd;
}
public string getid() {
return id;
}
public void setid(string id) {
this.id = id;
}
@override
public int hashcode() {
final int prime = 31;
int result = 1;
result = prime * result + ((id == null) ? 0 : id.hashcode());
return result;
}
@override
public boolean equals(object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getclass() != obj.getclass())
return false;
user other = (user) obj;
if (id == null) {
if (other.id != null)
return false;
} else if (!id.equals(other.id))
return false;
return true;
}
@override
public string tostring() {
return "user [id=" + id + ", name=" + name + ", pwd=" + pwd + "]";
}
}
逻辑层dao：
接口
实现类
package cn.hncu.user.dao;
import java.util.arraylist;
import java.util.list;
import org.dom4j.document;
import org.dom4j.element;
import org.dom4j.node;
import cn.hncu.user.domain.user;
import cn.hncu.user.utils.domfactory;
import cn.hncu.user.utils.idgenerate;
public class userdaoimpl implements userdao{
document dom=domfactory.getdom();
@override
public boolean reg(user user) {
// //title[@lang='eng']选取所有 title 元素，且这些元素拥有值为 eng 的 lang 属性。
// dom.selectsinglenode("//user[fn:lower-case(@name)='"+user.getname().tolowercase()+"']");
node node=dom.selectsinglenode("//user[name='"+user.getname()+"']");//user节点下值为user.getname()的name元素
//"name[='"+user.getname().tolowercase()+"']"
if(node!=null){
return false;
}
element root=dom.getrootelement();
element euser=root.addelement("user");
string id=idgenerate.getid();
euser.addattribute("id", id);
euser.addelement("name").settext(user.getname());
euser.addelement("pwd").settext(user.getpwd());
domfactory.save();
return true;
}
@override
public list<user> queryallusers() {
list<user> users=new arraylist<user>();
list<element> en=dom.selectnodes("//user");
for(element e:en){
string id=e.attributevalue("id");
string name=e.elementtext("name");
user user=new user();
user.setid(id);
user.setname(name);
users.add(user);
}
return users;
}
@override
public void deluser(string id) {
// system.out.println(id);
string xpath="//user[@id='"+id+"']";
node node=dom.selectsinglenode(xpath);
if(node!=null){
// system.out.println("del...");
node.getparent().remove(node);
domfactory.save();
}
}
}
工具包utils：
获取用户id
package cn.hncu.user.utils;
import java.util.uuid;
public class idgenerate {
private idgenerate(){
}
public static string getid(){
// return uuid.randomuuid().tostring();
return uuid.randomuuid().tostring().replace("-", "");
}
}
对数据库users.xml的dom获取和保存方法
这里用dom4j的包，，，所以要把dom4j两个包导入的相应的位置：
package cn.hncu.user.utils;
import java.io.fileoutputstream;
import org.dom4j.document;
import org.dom4j.documentexception;
import org.dom4j.io.saxreader;
import org.dom4j.io.xmlwriter;
public class domfactory {
private static document dom;
private static string filename;
static{
try {
saxreader r=new saxreader();
filename=domfactory.class.getclassloader().getresource("users.xml").getpath();
system.out.println("users.xml的路径:"+filename);///d:/apache-tomcat-7.0.30/webapps/usersweb/web-inf/classes/users.xml
//注意:获取tomcat中当前项目classpath下的资源方式
dom=r.read(filename);
} catch (documentexception e) {
e.printstacktrace();
}
}
public static document getdom(){
return dom;
}
public static void save(){
xmlwriter w;
try {
w = new xmlwriter(new fileoutputstream(filename));
w.write(dom);
w.close();
} catch (exception e) {
e.printstacktrace();
}
}
}
数据库：
<?xml version="1.0" encoding="utf-8"?> <users> </users>
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