dom4j XML Read and write modification operations

Import Java.io.File;
Import Java.io.FileOutputStream;
Import java.io.IOException;
Import java.util.ArrayList;
Import Java.util.HashSet;
Import Java.util.Iterator;
Import java.util.List;

Import Java.util.Set;
Import Org.apache.log4j.Logger;
Import org.dom4j.Document;
Import org.dom4j.DocumentException;
Import Org.dom4j.DocumentHelper;
Import org.dom4j.Element;
Import Org.dom4j.Node;
Import Org.dom4j.io.OutputFormat;
Import Org.dom4j.io.SAXReader;


Import Org.dom4j.io.XMLWriter;
	
	public class Persondao {private static final Logger Logger = Logger.getlogger (Persondao.class);
	
	Private Document Doc;
	Private String Xmlpath = Thread.CurrentThread (). Getcontextclassloader (). GetResource ("Persons.xml"). GetPath ();
	Private static final String error = "Error";
	
	Private static final String success = "Success";
	
	private static Persondao Persondao = new Persondao ();
	Private Persondao () {getpersondata ();
	Public Persondao getinstance () {return persondao; /** * Get people configuration Data * @return */Private document Getpersondata () {if (doc = = null) {//If Doc is empty, read file Inputxml = new files (xmlpath)
			;
			Saxreader Saxreader = new Saxreader ();
			try {doc = Saxreader.read (inputxml); catch (Documentexception e) {logger.error ("Error reading personnel profile.")
			", e);
	} return doc; /** * Update Personnel configuration * @return/private synchronized String Writepersondata () {//todo Want to add backup recovery mechanism try {FILEOUTP
			Utstream outputstream = new FileOutputStream (Xmlpath);
            OutputFormat format = Outputformat.createprettyprint ();
			Format.setencoding ("UTF-8");
			XMLWriter XMLWriter = new XMLWriter (Outputstream,format);
			Xmlwriter.write (Getpersondata ());
		Xmlwriter.close (); catch (IOException e) {logger.error ("Update the personnel Profile error.")
			", e);
		return error;
	return success; /** * To determine if the user name exists * @param name person * @return/public boolean isnameexist (String name) {//Get the name of all people list& Lt
		node> nodes = doc.selectnodes ("Persons/person/name"); Check the name of the new personWhether there is a set<string> Set = new hashset<string> ();
		for (int i = 0; i < nodes.size (); i++) {Set.add (Nodes.get (i) getText ());
		} if (Set.contains (name)) {return true;
	return false;
		/** * Additional staff * @param PERSONVO Staff Information * @return/public synchronized String Addperson (Personvo personvo) {
			The name cannot be empty if (personvo.getname () = = null) {logger.error ("person's name is null");
		return "Name.isnull";
				try {if (Isnameexist (Personvo.getname ())) {Logger.error ("name exist");
			return "Name.exist";
			///Create person node Element person = documenthelper.createelement (' person ');
				The following is the addition of the attribute node name, email, phone, and so on if (personvo.getname ()!= null) {Element name = documenthelper.createelement ("name");
				Name.settext (Personvo.getname ());
			Person.add (name);
				} if (Personvo.getphone ()!= null) {Element phone = documenthelper.createelement ("Phone");
				Phone.settext (Personvo.getphone ());
			Person.add (phone); } if (perSonvo.getemail ()!= null) {Element email = documenthelper.createelement ("email");
				Email.settext (Personvo.getemail ());
			Person.add (email);
				} if (personvo.getcomment ()!= null) {Element comment = documenthelper.createelement ("comment");
				Comment.settext (Personvo.getcomment ());
			Person.add (comment);
			} doc.getrootelement (). Add (person);
			Logger.info ("added XML content:" + doc.asxml ());
			Update to file String result = Writepersondata ();
		return result;
			catch (RuntimeException e) {logger.error ("exception occurred while adding personnel", e);
		return "Addperson.error"; /** * Modify personnel information, modify information other than the name * @param PERSONVO Personnel information * @return/public synchronized String Updateperson (Perso
			Nvo personvo) {//name cannot be empty if (personvo.getname () = = null) {logger.error ("person ' s name is null");
		return "Name.isnull";
		} list<element> List = Doc.selectnodes ("Persons/person/name");
		Element nameelement = null; Locate the name node for the person you want to modify for (int i = 0; i < list.size (); i++) {if (LIST.get (i). GetText (). Equals (Personvo.getname ())) {nameelement = List.get (i);
			Break
		}//If not found, indicates that the person does not exist if (nameelement = = null) {return "person.notexist";
		//Get the parent node, the person node Element parent = Nameelement.getparent ();
		If the node exists, modify the attribute, and if the node does not exist, add the node Element phone = parent.element ("Phone");
			if (phone = = null) {phone = documenthelper.createelement ("Phone");
			Phone.settext (Personvo.getphone ());
		Parent.add (phone);
		}else {Phone.settext (Personvo.getphone ());
		Element email = parent.element ("email");
			if (email = = NULL) {email = documenthelper.createelement ("email");
			Email.settext (Personvo.getemail ());
		Parent.add (email);
		}else {Email.settext (Personvo.getemail ());
		Element comment = parent.element ("comment");
			if (comment = = null) {comment = documenthelper.createelement ("comment");
			Comment.settext (Personvo.getcomment ());
		Parent.add (comment);
		}else {Comment.settext (personvo.getcomment ()); } logger.info ("ModifiedDocumentation: \ r \ n "+ doc.asxml ());
		String result = Writepersondata ();
	return result; /** * List all personnel information * @return/public List listpersons () {list<personvo> list = new Arraylist<personv
		O> ();
		Element root = Doc.getrootelement ();
		Iterator<element> it = Root.elementiterator ();
			while (It.hasnext ()) {element element = It.next ();
			String name = Element.selectsinglenode ("name"). GetText ();
			String phone = element.selectsinglenode ("Phone"). GetText ();
			String email = element.selectsinglenode ("email"). GetText ();
			
			String comment = Element.selectsinglenode ("comment"). GetText ();
			Personvo personvo = new Personvo ();
			Personvo.setcomment (comment);
			Personvo.setemail (email);
			Personvo.setname (name);
			Personvo.setphone (phone);
			List.add (PERSONVO);
		Logger.info ("Personvo info:" +personvo); 
	} return list; /** * Delete person * @param name * @return/Public String Deleteperson (string name) {//name cannot be null if (name = = Nu ll) {LoggeR.error ("person ' s name is null");
		return "Name.isnull";
		} list<element> List = Doc.selectnodes ("Persons/person/name");
		Element nameelement = null; Locate the name node for the person you want to modify for (int i = 0; i < list.size (); i++) {if list.get (i) GetText (). Equals (name)) {Nameelement
				= List.get (i);
			Break
		}//If not found, indicates that the person does not exist if (nameelement = = null) {return "person.notexist";
		//Get the parent node, the person node Element parent = Nameelement.getparent ();
		Boolean flag = Doc.getrootelement (). Remove (parent);//remove can only delete the immediate node logger.info ("Delete result:" + flag);
		Logger.info ("deleted document: \ r \ n" + doc.asxml ());
		if (!flag) {return "delete.failure";
		String result = Writepersondata ();
	return result;
		public static void Main (string[] args) {Persondao Persondao = new Persondao ();
		Personvo personvo = new Personvo ();
		Personvo.setname ("Zhang 34");
		Personvo.setphone ("1584");
		Personvo.setemail ("123email");
		Personvo.setcomment ("123comment"); System.out.println (Persondao.deleteperSon ("Zhang 34")) }
}