JSP基于dom解析xml实例详解


            本文实例讲述了JSP基于dom解析xml的方法。分享给大家供大家参考，具体如下：

初次学习用dom操作xml文件，有很多不足之处，牛人多给点建议，练习时我没对中文做乱码处理，也没做验证哦！O(∩_∩)O~

实体类：User





public class User {

 private String name;

 private String pwd;

 private String email;

 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 getEmail() {

 return email;

 }

 public void setEmail(String email) {

 this.email = email;

 }

}







数据访问层接口：UserDao





public interface UserDao {

 boolean login(String name, String pwd);

 void insertUser(User user);

 List<User> selectUser();

 void updateUser(User user);

 boolean deleteUser(String name);

 public User findByName(String name);

}







接口实现类：UserDaoImpl





public class UserDaoImpl implements UserDao {

 private static final String PATH="xml文件路径";

 private void build(Document dom) {

 try {

  //定义转换器

  Transformer f = TransformerFactory.newInstance().newTransformer();

  //设置输出的编码格式

  f.setOutputProperty(OutputKeys.ENCODING, "UTF-8");

  //构建dom源

  DOMSource source = new DOMSource(dom);

  //指定文件存放的目标路劲

  StreamResult sr = new StreamResult(new File(PATH));

  //执行转换操作

  f.transform(source, sr);

 } catch (Exception e) {

  e.printStackTrace();

 }

 }

 //登陆

 public boolean login(String name, String pwd) {

 boolean flag = false;

 try {

  //根据以有的xml文件创建Document对象

  Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File(PATH));

  //获取user节点下的子节点

  NodeList list = dom.getElementsByTagName("user");

  //遍历list，数据匹配退出

  for(int i = 0; i<list.getLength(); i++) {

  Element el = (Element)list.item(i);

  if(name.equals(el.getAttribute("name")) && pwd.equals(el.getAttribute("pwd"))) {

   flag = true;

   break;

  }

  }

 } catch (Exception e) {

  // TODO Auto-generated catch block

  e.printStackTrace();

 } 

 return flag;

 }

 //添加操作

 public void insertUser(User user) {

 try {

  //创建全新的Document对象

  Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();

  //创建根节点users

  Element el = dom.createElement("users");

  //将根节点添加到dom中

  dom.appendChild(el);

  //创建子节点

  Element e2 = dom.createElement("user");

  //将子节点添加到根节点中

  el.appendChild(e2);

  //取得xml文件中现有的信息

  List<User> users = this.selectUser();

  for(int i = 0; i < users.size(); i++){

  //创建节点user

  Element el3 = dom.createElement("user");

  User us =users.get(i);

  //设置节点的属性（name,pwd,email）

  el3.setAttribute("name", us.getName());

  el3.setAttribute("pwd", us.getPwd());

  el3.setAttribute("email", us.getEmail());

  //添加到根节点中

  el.appendChild(el3);

  }

  e2.setAttribute("name", user.getName());

  e2.setAttribute("pwd", user.getPwd());

  e2.setAttribute("email", user.getEmail());

  build(dom);

 } catch (ParserConfigurationException e) {

  // TODO Auto-generated catch block

  e.printStackTrace();

 }

 }

 //查询操作

 public List<User> selectUser() {

 List<User> userList = new ArrayList<User>();

 try {

  //根据已有的xml文件创建dom

  Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File(PATH));

  //获取所有user节点下的子节点

  NodeList list = dom.getElementsByTagName("user");

  for(int i = 0;i <list.getLength();i++){

  User user =new User();

  Element element = (Element)list.item(i);

  user.setName(element.getAttribute("name"));

  user.setPwd(element.getAttribute("pwd"));

  user.setEmail(element.getAttribute("email"));

  userList.add(user);

  }

 } catch (Exception e) {

  // TODO Auto-generated catch block

  e.printStackTrace();

 }

 return userList;

 }

 //修改操作

 public void updateUser(User user) {

 try {

  //根据以有的xml文件创建dom

  Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File(PATH));

  //获取user节点下的子节点

  NodeList list = dom.getElementsByTagName("user");

  //遍历list

  for(int i = 0;i < list.getLength();i++) {

  Element el = (Element)list.item(i);

  //根据name属性去修改

  if(user.getName().equals(el.getAttribute("name"))) {

   el.setAttribute("pwd", user.getPwd());

   el.setAttribute("email", user.getEmail());

   build(dom);

  }

  }

 } catch (SAXException e) {

  // TODO Auto-generated catch block

  e.printStackTrace();

 } catch (IOException e) {

  // TODO Auto-generated catch block

  e.printStackTrace();

 } catch (ParserConfigurationException e) {

  // TODO Auto-generated catch block

  e.printStackTrace();

 }

 }

 //删除操作

 public boolean deleteUser(String name) {

 try {

  //根据以有xml文件创建domcumet对象

  Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File(PATH));

  //获取user节点下的子节点

  NodeList list = dom.getElementsByTagName("user");

  //遍历list

  for(int i=0;i<list.getLength();i++) {

  Element el = (Element)list.item(i);

  if(name.equals(el.getAttribute("name"))) {

   el.getParentNode().removeChild(el);

   build(dom);

   return true;

  }

  }

 } catch (Exception e) {

  // TODO: handle exception

 }

 return false;

 }

 //根据name查找

 public User findByName(String name) {

 User user = new User();

 try {

  //根据以后的xml文件创建document对象

  Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File(PATH));

  //获取user节点下的子节点集合

  NodeList list = dom.getElementsByTagName("user");

  for(int i=0;i<list.getLength();i++) {

  Element el = (Element)list.item(i);

  if(name.equals(el.getAttribute("name"))) {

   user.setName(el.getAttribute("name"));

   user.setPwd(el.getAttribute("pwd"));

   user.setEmail(el.getAttribute("email"));

   break;

  }

  }

 } catch (Exception e) {

  e.printStackTrace();

 }

 return user;

 }

}







业务逻辑层接口：UserService





boolean login(String name, String pwd);

void insertUser(User user);

List<User> selectUser();

void updateUser(User user);

boolean deleteUser(String name);

public User findByName(String name);







接口实现类：UserServiceImpl





public class UserServiceImpl implements UserService {

 UserDao dao = new UserDaoImpl();

 public boolean login(String name, String pwd) {

 return dao.login(name, pwd);

 }

 public void insertUser(User user) {

 dao.insertUser(user);

 }

 public List<User> selectUser() {

 return dao.selectUser();

 }

 public void updateUser(User user) {

 dao.updateUser(user);

 }

 public boolean deleteUser(String name) {

 return dao.deleteUser(name);

 }

 public User findByName(String name) {

 return dao.findByName(name);

 }

}



控制层：UserAction





public class UserAction extends ActionSupport{

  private User user;

 public User getUser() {

 return user;

 }

 public void setUser(User user) {

 this.user = user;

 }

 UserService userService = new UserServiceImpl();

 public String selectUser(){

 HttpServletRequest request = ServletActionContext.getRequest();

 List<User> users = new ArrayList<User>();

 users = userService.selectUser();

 request.setAttribute("USER", users);

 return "select";

 }

 /**

 * 登陆

 * @return

 */

 public String login(){

 if(user.getName() != null && user.getPwd() != null) {

  boolean flag = userService.login(user.getName(), user.getPwd());

  if(flag) {

  return SUCCESS;

  }

 }

 return ERROR;

 }

 /**

 * 修改

 * @return

 */

 public String update(){

 userService.updateUser(user);

 return "update";

 }

 /**

 * 编辑

 * @return

 */

 public String edit(){

 HttpServletRequest request = ServletActionContext.getRequest();

 String name = request.getParameter("uName");

 if(name != null) {

  User u = userService.findByName(name);

  request.setAttribute("USER", u);

 }

 return "edit";

 }

 /**

 * 删除

 * @return

 */

 public String delete(){

 HttpServletRequest request = ServletActionContext.getRequest();

 String name = request.getParameter("uName");

 boolean flag = userService.deleteUser(name);

 System.out.println(flag);

 return SUCCESS;

 }

  /**

   * 添加

   * @return

   */

 public String insert(){

 userService.insertUser(user);

 return "insert";

 }

}







struts.xml配置（本人用的的struts2）：





<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE struts PUBLIC

  "-//Apache Software Foundation//DTD Struts Configuration 2.1.7//EN"

  "http://struts.apache.org/dtds/struts-2.1.7.dtd">

<struts>

  <package name="file" extends="struts-default">

   <action name="list" class="com.jun.action.UserAction" method="selectUser">

    <result name="select">/list.jsp</result>

   </action>

   <action name="login" class="com.jun.action.UserAction" method="login">

    <result name="success" type="redirectAction">/list.action</result>

    <result name="error">/login.jsp</result>

   </action>

   <action name="insert" class="com.jun.action.UserAction" method="insert">

    <result name="insert" type="redirectAction">/list.action</result>

   </action>

   <action name="delete" class="com.jun.action.UserAction" method="delete">

    <result type="redirect">/list.action</result>  

   </action>

   <action name="update" class="com.jun.action.UserAction" method="update">

    <result name="update" type="redirectAction">/list.action</result>  

   </action>

   <action name="edit" class="com.jun.action.UserAction" method="edit">

    <result name="edit">/update.jsp</result>  

   </action>

  </package>

</struts>



web.xml配置





<?xml version="1.0" encoding="UTF-8"?>

<web-app version="2.5" 

 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_2_5.xsd">

 <welcome-file-list>

  <welcome-file>index.jsp</welcome-file>

 </welcome-file-list>

 <filter>

  <filter-name>struts2</filter-name>

  <filter-class>

  org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter

  </filter-class>

 </filter>

 <filter-mapping>

  <filter-name>struts2</filter-name>

  <url-pattern>/*</url-pattern>

 </filter-mapping>

</web-app>



四个页面：login.jsp  list.jsp insert.jsp,update.jsp

login.jsp





<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>

<%

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

 <head>

  <base href="<%=basePath%>">

  <title>My JSP 'login.jsp' starting page</title>

 <meta http-equiv="pragma" content="no-cache">

 <meta http-equiv="cache-control" content="no-cache">

 <meta http-equiv="expires" content="0">  

 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

 <meta http-equiv="description" content="This is my page">

 <!--

 <link rel="stylesheet" type="text/css" href="styles.css">

 -->

 </head>

 <body>

  <a href="list.action">首页</a>|<a href="insert.jsp">注册</a>

  <form action="login.action" method="post">

  <table>

  <tr>

    <td> 用户名：</td><td><input name="user.name" type="text"></td>

  </tr>

  <tr>

    <td> 密码：</td><td><input type="password" name="user.pwd"></td>

  </tr>

  <tr>

    <td colspan="2" align="center"><input type="submit" value="登录"></td>

  </tr>

    </table> 

  </form>

 </body>

</html>



list.jsp





<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>

<%@ taglib uri="/struts-tags" prefix="s"%>

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>

<%

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

 <head>

  <base href="<%=basePath%>">

  <title>My JSP 'list.jsp' starting page</title>

 <meta http-equiv="pragma" content="no-cache">

 <meta http-equiv="cache-control" content="no-cache">

 <meta http-equiv="expires" content="0">  

 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

 <meta http-equiv="description" content="This is my page">

 <!--

 <link rel="stylesheet" type="text/css" href="styles.css">

 -->

 </head>

 <body >

 <a href="insert.jsp">注册</a>

  <table border="1">

  <tr>

   <td align="center" colspan="6"><font size="+3">用户列表</font></td>

  </tr>

   <tr>

    <td>序号</td><td>用户名</td><td>密码</td><td>邮箱</td><td>删除</td><td>编辑</td>

   </tr>

   <c:forEach items="${USER}" var="u" varStatus="temp">

    <tr>

    <td>${temp.index+1}</td><td>${u.name }</td><td>${u.pwd }</td><td>${u.email}</td><td><a href="delete.action?uName=${u.name}">删除</a></td><td><a href="edit.action?uName=${u.name }">编辑</a></td>

    </tr>

  </c:forEach>

  </table>

 </body>

</html>



insert.jsp





<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>

<%

 String path = request.getContextPath();

 String basePath = request.getScheme() + "://"

  + request.getServerName() + ":" + request.getServerPort()

  + path + "/";

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

 <head>

 <base href="<%=basePath%>">

 <title>My JSP 'register.jsp' starting page</title>

 <meta http-equiv="pragma" content="no-cache">

 <meta http-equiv="cache-control" content="no-cache">

 <meta http-equiv="expires" content="0">

 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

 <meta http-equiv="description" content="This is my page">

 <!--

 <link rel="stylesheet" type="text/css" href="styles.css">

 -->

 </head>

 <body>

 <a href="list.action">首页</a>

 <form action="insert.action" method="post">

  <table>

  <tr>

   <td>

   用户名：

   </td>

   <td>

   <input name="user.name" type="text">

   </td>

  </tr>

  <tr>

   <td>

   密码：

   </td>

   <td>

   <input type="password" name="user.pwd">

   </td>

  </tr>

  <tr>

   <td>

   邮箱：

   </td>

   <td>

   <input type="text" name="user.email">

   </td>

  </tr>

  <tr>

   <td colspan="2" align="center">

   <input type="submit" value="提交">

   </td>

  </tr>

  </table>

 </form>

 </body>

</html>







update.jsp





<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>

<%

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

 <head>

  <base href="<%=basePath%>">

  <title>My JSP 'update.jsp' starting page</title>

 <meta http-equiv="pragma" content="no-cache">

 <meta http-equiv="cache-control" content="no-cache">

 <meta http-equiv="expires" content="0">  

 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

 <meta http-equiv="description" content="This is my page">

 <!--

 <link rel="stylesheet" type="text/css" href="styles.css">

 -->

 </head>

 <body>

  <a href="list.action">首页</a>

  <h2>更新操作</h2>

  <form action="update.action" method="post">

  <table>

  <c:set value="${USER}" var="user"></c:set>

  <tr>

    <td> 用户名：</td><td><input readonly="readonly" name="user.name" value="${user.name}" type="text"></td>

  </tr>

  <tr>

    <td> 密码：</td><td><input type="password" value="${user.pwd }" name="user.pwd"></td>

  </tr>

  <tr>

    <td> 邮箱：</td><td><input type="text" value="${user.email }" name="user.email"></td>

  </tr>

  <tr>

    <td colspan="2" align="center"><input type="submit" value="保存"></td>

  </tr>

    </table> 

  </form>

 </body>

</html>







本人学习所用的user.xml文件





<?xml version="1.0" encoding="UTF-8"?>

<users>

<user email=aaa@sina.com name="bbb" pwd="aaaaaa"/>

<user email=bbb@sina.com name="ccc" pwd="aaaaaa"/>

</users>







希望本文所述对大家jsp程序设计有所帮助。