XML operation example → implement user login

Package Cn.zyw.utils;import Java.io.file;import Java.io.filenotfoundexception;import java.io.FileOutputStream; Import Java.io.unsupportedencodingexception;import Org.dom4j.document;import Org.dom4j.documentexception;import    Org.dom4j.io.outputformat;import Org.dom4j.io.saxreader;import Org.dom4j.io.xmlwriter;//3public class XmlUtils {    private static String filepath;        static{Filepath=xmlutils.class.getclassloader (). GetResource ("Users.xml"). GetPath ();    Filepath=filepath.replace ("%20", "");        } public static Document GetDocument () throws exception{saxreader reader = new Saxreader ();        Document document = Reader.read (new File (filepath));    return document; public static void Write2xml (document document) throws exception{OutputFormat format = Outputformat.createpre        Ttyprint ();        Format.setencoding ("UTF-8");        XMLWriter writer = new XMLWriter (new FileOutputStream (filepath), format);        Writer.write (document); WritEr.close (); }}

Sometimes we want to do a small project to save certain data, if using a database is certainly possible. But it always feels like a waste of resources. So today I learned a little bit of XML summarized as follows:

The 1:xml file is as follows:

　　

<?xml version= "1.0" encoding= "UTF-8"?><users>    <user id= "234343434" Username= "AAA" password= "123" email= "[email protected]" birthday= "1900-09-18" nickname= "Hadron"/></users>

2: Tool class for manipulating XML files

Xmlutils.java

Package cn.zyw.utils;

Import Java.io.File;
Import java.io.FileNotFoundException;
Import Java.io.FileOutputStream;
Import java.io.UnsupportedEncodingException;

Import org.dom4j.Document;
Import org.dom4j.DocumentException;
Import Org.dom4j.io.OutputFormat;
Import Org.dom4j.io.SAXReader;
Import Org.dom4j.io.XMLWriter;

3
public class Xmlutils {
private static String filepath;
static{
Filepath=xmlutils.class.getclassloader (). GetResource ("Users.xml"). GetPath ();
Filepath=filepath.replace ("%20", "");
}
public static Document GetDocument () throws exception{
Saxreader reader = new Saxreader ();
Document document = Reader.read (new File (filepath));
return document;
}
public static void Write2xml (document document) throws exception{
OutputFormat format = Outputformat.createprettyprint ();
Format.setencoding ("UTF-8");
XMLWriter writer = new XMLWriter (new FileOutputStream (filepath), format);
Writer.write (document);
Writer.close ();
}

}

Package Cn.zyw.utils;import Java.io.file;import Java.io.filenotfoundexception;import java.io.FileOutputStream; Import Java.io.unsupportedencodingexception;import Org.dom4j.document;import Org.dom4j.documentexception;import    Org.dom4j.io.outputformat;import Org.dom4j.io.saxreader;import Org.dom4j.io.xmlwriter;//3public class XmlUtils {    private static String filepath;        static{Filepath=xmlutils.class.getclassloader (). GetResource ("Users.xml"). GetPath ();    Filepath=filepath.replace ("%20", "");        } public static Document GetDocument () throws exception{saxreader reader = new Saxreader ();        Document document = Reader.read (new File (filepath));    return document; public static void Write2xml (document document) throws exception{OutputFormat format = Outputformat.createpre        Ttyprint ();        Format.setencoding ("UTF-8");        XMLWriter writer = new XMLWriter (new FileOutputStream (filepath), format);        Writer.write (document); WritEr.close (); }}

3: User login for DAO

Userdao. java

Package Cn.zyw.dao;

Import Cn.zyw.domain.User;
5
Public interface Userdao {

void Add (user user);

User Find (string Username, string password);

Find whether registered users exist in the database
Boolean find (String username);

}

Package Cn.zyw.dao;import Cn.zyw.domain.user;//5public interface Userdao {    void Add (user user);    User Find (string Username, string password);    Finds whether the registered user has a Boolean find in the database    (String username);

4: Implementation class for user login

Userdaoimpl. java

Package Cn.zyw.dao.impl;

Import Java.text.SimpleDateFormat;

Import org.dom4j.Document;
Import org.dom4j.Element;

Import Cn.zyw.dao.UserDao;
Import Cn.zyw.domain.User;
Import Cn.zyw.utils.XmlUtils;
2
public class Userdaoimpl implements Userdao {
public void Add (user user) {
try {
Document document=xmlutils.getdocument ();
Element root=document.getrootelement ();//Get root node
Element user_tag=root.addelement ("user");
User_tag.setattributevalue ("id", User.getid ());
User_tag.setattributevalue ("username", user.getusername ());
User_tag.setattributevalue ("Password", User.getpassword ());
User_tag.setattributevalue ("Email", user.getemail ());
User_tag.setattributevalue ("nickname", User.getnickname ());
User_tag.setattributevalue ("Birthday", User.getbirthday () ==null? "": User.getbirthday (). toLocaleString ());
Xmlutils.write2xml (document);
} catch (Exception e) {
throw new RuntimeException (e);
}
}
Public User Find (String username,string password) {

try {
Document document=xmlutils.getdocument ();
Element e= (Element) Document.selectsinglenode ("//user[@username = '" +username+ "' and @password = '" +password+ "']");
if (e==null)
return null;
User User=new user ();
User.setusername (E.attributevalue ("username"));//Get the value inside the XML
User.setnickname (E.attributevalue ("nickname"));
User.setpassword (E.attributevalue ("password"));
User.setemail (E.attributevalue ("email"));
User.setid (E.attributevalue ("id"));
String date=e.attributevalue ("Birthday");
if (Date==null | | date.equals ("")) {
User.setbirthday (NULL);
}else{
SimpleDateFormat df=new SimpleDateFormat ("Yyyy-mm-dd");
User.setbirthday (Df.parse (date));
}
return user;
} catch (Exception e) {
throw new RuntimeException (e);
}
}
Find whether registered users exist in the database
public boolean find (String username) {
try {
Document document=xmlutils.getdocument ();
Element e= (Element) Document.selectsinglenode ("//user[@username = '" +username+ "']");
if (e==null) {
return false;
}

return true;
} catch (Exception e) {
throw new RuntimeException (e);
}
}

}

Package Cn.zyw.dao.impl;import Java.text.simpledateformat;import Org.dom4j.document;import org.dom4j.Element; Import Cn.zyw.dao.userdao;import Cn.zyw.domain.user;import Cn.zyw.utils.xmlutils;//2public class UserDaoImpl            Implements Userdao {public void Add (user user) {try {Document document=xmlutils.getdocument ();            Element root=document.getrootelement ();//Get root node Element user_tag=root.addelement ("user");            User_tag.setattributevalue ("id", User.getid ());            User_tag.setattributevalue ("username", user.getusername ());            User_tag.setattributevalue ("Password", User.getpassword ());            User_tag.setattributevalue ("Email", user.getemail ());            User_tag.setattributevalue ("nickname", User.getnickname ()); User_tag.setattributevalue ("Birthday", User.getbirthday () ==null?            "": User.getbirthday (). toLocaleString ());        Xmlutils.write2xml (document); } catch (Exception e) {throw new RunTimeexception (e); }} public User find (String username,string password) {try {Document document=xmlutils.getdocumen            T ();            Element e= (Element) Document.selectsinglenode ("//user[@username = '" +username+ "' and @password = '" +password+ "']");            if (e==null) return null;            User User=new user ();            User.setusername (E.attributevalue ("username"));//Get the value inside the XML user.setnickname (E.attributevalue ("nickname"));            User.setpassword (E.attributevalue ("password"));            User.setemail (E.attributevalue ("email"));            User.setid (E.attributevalue ("id"));            String date=e.attributevalue ("Birthday");                            if (Date==null | | date.equals ("")) {user.setbirthday (null);                }else{SimpleDateFormat df=new SimpleDateFormat ("Yyyy-mm-dd");            User.setbirthday (Df.parse (date));                    } return user; } CatCH (Exception e) {throw new RuntimeException (e); }}//Find whether the registered user exists in the database with public boolean find (String username) {try {Document document=xmlutils.            GetDocument ();            Element e= (Element) Document.selectsinglenode ("//user[@username = '" +username+ "']");            if (E==null) {return false;                            } return true;        } catch (Exception e) {throw new RuntimeException (e); }    }    }

5: Test of User Login

Userdaotest.java

Package junit.test;

Import Java.util.Date;
Import Org.junit.Test;
Import Cn.zyw.dao.UserDao;
Import Cn.zyw.dao.impl.UserDaoImpl;
Import Cn.zyw.domain.User;
4
public class Userdaotest {
@Test
public void Testadd () {
User User=new user ();
User.setbirthday (New Date ());
User.setemail ("[email protected]");
User.setid ("34343434");
User.setnickname ("Plum");
User.setpassword ("123");
User.setusername ("AAA");

Userdao dao=new Userdaoimpl ();
Dao.add (user);
}
@Test
public void Testfind () {
Userdao dao=new Userdaoimpl ();
User user=dao.find ("AAA", "123");
String Aa=user.getemail ();
if (Aa.endswith ("KK"))
{
System.out.println ("KKDF");
}
}
@Test
public void Testfindbyusername () {
Userdao dao=new Userdaoimpl ();
Boolean B=dao.find ("AAA");

}
}

Package Junit.test;import Java.util.date;import Org.junit.test;import cn.zyw.dao.userdao;import Cn.zyw.dao.impl.userdaoimpl;import Cn.zyw.domain.user;//4public class Userdaotest {    @Test public    Void Testadd () {        user user=new User ();        User.setbirthday (New Date ());        User.setemail ("[email protected]");        User.setid ("34343434");        User.setnickname ("Plum");        User.setpassword ("123");        User.setusername ("AAA");                        Userdao dao=new Userdaoimpl ();        Dao.add (user);    }    @Test public    void Testfind () {        Userdao dao=new userdaoimpl ();        User user=dao.find ("AAA", "123");        String Aa=user.getemail ();        if (Aa.endswith ("KK"))        {            System.out.println ("KKDF");        }    }    @Test public    void Testfindbyusername () {        Userdao dao=new userdaoimpl ();        Boolean B=dao.find ("AAA");}    }

XML operation example → implement user login