jsp基于XML实现用户登录与注册的实例解析(附源

简单的基于xml做数据库的登录与注册

主题介绍:

1.xml的读取和存储,主要是用到dom4j技术,(网络中的文件存储路径采用classLoader)

文件的读取和存储,写了一个工厂类

public class DocumentFactory { private static Document dom=null;//需要共享一个dom,所以需要设置为static private static String; private static String filename; //写一个静态块实现对dom树的读取 static{//dom4j技术 SAXReader read=new SAXReader(); filename=DocumentFactory.class.getClassLoader().getResource(name).getPath();//采用类加载器进行读取文件 try { dom=read.read(filename); } catch (DocumentException e) {<span> e.printStackTrace();}}</span> //主要获得和存储的两个函数(采用单例模式)(必须共享一个dom数) public static Document getDocument(){ //获得xml中的dom树 return dom; } //注册之后需要保存 public static void Save() { XMLWriter wr; try { wr = new XMLWriter(new FileOutputStream(filename)); }catch (Exception e1) { throw new RuntimeException("存储文件时读文件失败"); } try { wr.write(dom); } catch (IOException e) { throw new RuntimeException("写文件失败"+e.getMessage()); }finally{ try { if(wr!=null){ wr.close(); } } catch (IOException e) { throw new RuntimeException("关流失败"+e.getMessage());}}} }

2.前台的技术:基本上就是界面的搭建和将数据传到后台进行处理。以及部分的必填选项要求。

两个页面的代码:
//登录

<body> <form action='login' method="post"> 用户名:<input type="text" /><br/> 密 码 :<input type="text" /><br/> 验证码:<input type="text"><img src="https://www.jb51.net/LOGIN/immg"><a href="javascript:flush()">看不清</a>//需要重写一个js进行刷新 <br/> <input type="submit"value="登录" /> <input type="reset"value="重置" /> <a href='https://www.jb51.net/jsps/Reg.jsp'>注册</a> </form>

//登录后台的处理

public class Login extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8");//设置utf-8的编码格式去接收 response.setContentType("text/html;charset=UTF-8");//<span>设置页面显示方式,这个设置必须要在获得输出流之前设置,不然设置都没有用,照样会出现乱码</span> 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</TITLE>"); out.println(" <meta http-equiv='content-type' content='text/html; charset=UTF-8'> </HEAD>"); out.println(" <BODY>"); String name=request.getParameter("name"); String pwd=request.getParameter("pwd"); String check=request.getParameter("checkCode");//从界面获得验证码输入的值 ImgDemo id =new ImgDemo(); String str=id.getStr(); if(!check.equals(str)){ out.println("登录失败,验证码不正确!!");//要是验证码不符合,直接返回登录界面 out.print("<a href='https://www.jb51.net/index.jsp'>返回登录</a>"); return; } // System.out.println("11"+check); // System.out.println("22"+str); //登录前获得所有的对象 Document dom=DocumentFactory.getDocument(); boolean flag=false; Element root=dom.getRootElement(); Iterator<Element> it=root.elementIterator(); while(it.hasNext()){ Element ele =it.next(); String nameC=ele.attributeValue("name"); String pwdC=ele.attributeValue("pwd"); if(name.trim().equals(nameC)&&pwdC.equals(pwdC)){ flag=true; break; } } if(flag){ out.print("<font color='red' size='8px'>恭喜您,登陆成功!</font>"); out.println("<a href='https://www.jb51.net/index.jsp'>返回登录</a>"); }else{ out.print("用户名和密码不匹配。登录失败。。。"); out.println("<a href='https://www.jb51.net/index.jsp'>返回登录</a>"); } out.println(" </BODY>"); out.println("</HTML>"); out.flush(); out.close(); } }

//注册

<body> <form action='reg' method="post"> 用户 名:<input type="text" onblur="check()"/><span></span><br/> 密 码 : <input type="text" onblur="check1()"/><span></span><br/> 确认密码 :<input type="text" onblur="check2()"/><span></span><br/> <input type="submit"value="注册" /> <input type="reset"value="重置" /> </form> </body>

//注册的后台处理

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