JSP基于dom解析xml实例详解
编程学习 2021-07-05 11:23www.dzhlxh.cn编程入门
这篇文章主要介绍了JSP基于dom解析xml的方法,以完整实例形式较为详细的分析了JSP使用dom针对xml文件解析的相关技巧,具有一定参考借鉴价值,需要的朋友可以参考下
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。
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