JSP parsing xml example based on dom
- 2021-08-21 21:06:19
- OfStack
In this paper, an example is given to explain the method of JSP parsing xml based on dom. Share it for your reference, as follows:
For the first time, I learned to operate xml files with dom. There are many shortcomings. Niu Ren gives some suggestions. I didn't do garbled processing in Chinese during practice, and I didn't do verification! O (φ _ φ) O ~
Entity class: 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;
}
}
Data access layer interface: 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);
}
Interface Implementation Class: UserDaoImpl
public class UserDaoImpl implements UserDao {
private static final String PATH="xml File path ";
private void build(Document dom) {
try {
// Define a converter
Transformer f = TransformerFactory.newInstance().newTransformer();
// Set the encoding format of the output
f.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
// Build dom Source
DOMSource source = new DOMSource(dom);
// Specify the target strength of file storage
StreamResult sr = new StreamResult(new File(PATH));
// Perform a conversion operation
f.transform(source, sr);
} catch (Exception e) {
e.printStackTrace();
}
}
// Landing
public boolean login(String name, String pwd) {
boolean flag = false;
try {
// According to some xml File creation Document Object
Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File(PATH));
// Get user Child nodes under the node
NodeList list = dom.getElementsByTagName("user");
// Traversal list Data matching exits
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;
}
// Add operation
public void insertUser(User user) {
try {
// Create a brand new Document Object
Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();
// Create a root node users
Element el = dom.createElement("users");
// Add the root node to the dom Medium
dom.appendChild(el);
// Create child nodes
Element e2 = dom.createElement("user");
// Add child nodes to the root node
el.appendChild(e2);
// Acquire xml Existing information in the file
List<User> users = this.selectUser();
for(int i = 0; i < users.size(); i++){
// Create Node user
Element el3 = dom.createElement("user");
User us =users.get(i);
// Set the properties of the node ( name,pwd,email )
el3.setAttribute("name", us.getName());
el3.setAttribute("pwd", us.getPwd());
el3.setAttribute("email", us.getEmail());
// Add to the root node
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();
}
}
// Query operation
public List<User> selectUser() {
List<User> userList = new ArrayList<User>();
try {
// According to the existing xml File creation dom
Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File(PATH));
// Get all user Child nodes under the node
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;
}
// Modification operation
public void updateUser(User user) {
try {
// According to some xml File creation dom
Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File(PATH));
// Get user Child nodes under the node
NodeList list = dom.getElementsByTagName("user");
// Traversal list
for(int i = 0;i < list.getLength();i++) {
Element el = (Element)list.item(i);
// According to name Property to modify
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();
}
}
// Delete operation
public boolean deleteUser(String name) {
try {
// According to the following xml File creation domcumet Object
Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File(PATH));
// Get user Child nodes under the node
NodeList list = dom.getElementsByTagName("user");
// Traversal 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;
}
// According to name Find
public User findByName(String name) {
User user = new User();
try {
// According to later xml File creation document Object
Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File(PATH));
// Get user Child node collection under node
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;
}
}
Business logic layer interface: 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);
Interface Implementation Class: 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);
}
}Control layer: 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";
}
/**
* Landing
* @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;
}
/**
* Modify
* @return
*/
public String update(){
userService.updateUser(user);
return "update";
}
/**
* Edit
* @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";
}
/**
* Delete
* @return
*/
public String delete(){
HttpServletRequest request = ServletActionContext.getRequest();
String name = request.getParameter("uName");
boolean flag = userService.deleteUser(name);
System.out.println(flag);
return SUCCESS;
}
/**
* Add
* @return
*/
public String insert(){
userService.insertUser(user);
return "insert";
}
}
struts. xml configuration (my 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 configuration
<?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>4 pages: 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"> Home page </a>|<a href="insert.jsp"> Registration </a>
<form action="login.action" method="post">
<table>
<tr>
<td> User name: </td><td><input name="user.name" type="text"></td>
</tr>
<tr>
<td> Password: </td><td><input type="password" name="user.pwd"></td>
</tr>
<tr>
<td colspan="2" align="center"><input type="submit" value=" Login "></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"> Registration </a>
<table border="1">
<tr>
<td align="center" colspan="6"><font size="+3"> User list </font></td>
</tr>
<tr>
<td> Serial number </td><td> User name </td><td> Password </td><td> Mailbox </td><td> Delete </td><td> Edit </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}"> Delete </a></td><td><a href="edit.action?uName=${u.name }"> Edit </a></td>
</tr>
</c:forEach>
</table>
</body>
</html>insert.jsp
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);
}
update.jsp
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);
}
The user. xml file I used for my study
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);
}
I hope this article is helpful to everyone's jsp programming.