xmlgenericmodel.java

java 开发的一个电子邮局,挺实用的

/* CVS ID: $Id: XMLGenericModel.java,v 1.2 2000/12/30 10:39:09 wastl Exp $ */
package net.wastl.webmail.xml;

import java.util.*;
import java.io.*;

import org.w3c.dom.*;
import org.apache.xerces.dom.*;
import org.apache.xerces.parsers.*;

import net.wastl.webmail.server.*;

/*
 * XMLGenericModel.java
 *
 * Created: Thu May  4 15:53:12 2000
 *
 * Copyright (C) 2000 Sebastian Schaffert
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

/**
 * A generic representation of WebMail data. Contains mainly state information 
 * and the system configuration
 *
 * @author Sebastian Schaffert
 * @version
 */

public class XMLGenericModel  {

    protected Document root;

    protected Element sysdata;

    protected Element statedata;

    protected WebMailServer parent;

    protected long current_id=0;

    protected DOMParser parser;
   
    public XMLGenericModel(WebMailServer parent, Element rsysdata) {
	this.parent=parent;

	parser=new DOMParser(); 

	initRoot();

	statedata=root.createElement("STATEDATA");

	NodeList nl=root.getDocumentElement().getElementsByTagName("STATEDATA");
	if(nl.getLength() > 0) {
	    System.err.println("*** Warning: Webmail usermodel template contained a STATEDATA tag, although this should only be created at runtime!");
	    root.getDocumentElement().replaceChild(statedata,nl.item(0));
	} else {
	    root.getDocumentElement().appendChild(statedata);
	}
	    
	this.sysdata=rsysdata;	
	
    }
    
    protected void initRoot() {
	// Create a new usermodel from the template file
	try {
	    parser.parse("file://"+parent.getProperty("webmail.xml.path")+
			 System.getProperty("file.separator")+"generic_template.xml");
// 	    parser.parse(parent.getProperty("webmail.xml.path")+
// 			 System.getProperty("file.separator")+"generic_template.xml");
	} catch(Exception ex) {
	    System.err.println("Error parsing WebMail UserModel template "+ex.getMessage());
	    ex.printStackTrace();
	}
	root=parser.getDocument();
    }

    public Document getRoot() {
	return root;
    }

    public Element getStateData() {
	return statedata;
    }

    public void init() {
	setStateVar("base uri",parent.getBasePath());
	setStateVar("img base uri",parent.getImageBasePath()+
		    "/"+parent.getDefaultLocale().getLanguage()+
		    "/"+parent.getDefaultTheme());
	setStateVar("webmail version",parent.getVersion());
	setStateVar("operating system",System.getProperty("os.name")+" "+
		    System.getProperty("os.version")+"/"+System.getProperty("os.arch"));
	setStateVar("java virtual machine",System.getProperty("java.vendor")+" "+
		    System.getProperty("java.vm.name")+" "+System.getProperty("java.version"));
    }

    public void update() {
	// Insert the sysdata and userdata objects into the usermodel tree
	try {
	    NodeList nl=root.getElementsByTagName("SYSDATA");
	    root.getDocumentElement().replaceChild(root.importNode(sysdata,true),nl.item(0));
	} catch(ArrayIndexOutOfBoundsException ex) {
	    System.err.println("The WebMail GenericModel template file didn't contain a SYSDATA tag.");
	} catch(DOMException ex) {
	    System.err.println("Something went wrong with the XML generic model.");
	}
    }

    /**
     * Create a unique ID.
     * Important: This returns a new Unique ID within this session.
     * It should be used to generate IDs for Folders and messages so that they can be easily referenced
     */
    public String getNextID() {
	return Long.toHexString(++current_id).toUpperCase();
    }
    
    public synchronized void setException(Exception ex) {
	Element exception=root.createElement("EXCEPTION");
	Element ex_message=root.createElement("EX_MESSAGE");
	Element ex_stacktrace=root.createElement("EX_STACKTRACE");
	exception.appendChild(ex_message);
	exception.appendChild(ex_stacktrace);

	Text msg=root.createTextNode(ex.getMessage());
	ex_message.appendChild(msg);

	String my_stack="";
	CharArrayWriter cstream=new CharArrayWriter();
	ex.printStackTrace(new PrintWriter(cstream));
	my_stack=cstream.toString();
	CDATASection stack=root.createCDATASection(my_stack);
	ex_stacktrace.appendChild(stack);

	NodeList nl=statedata.getElementsByTagName("EXCEPTION");
	if(nl.getLength() > 0) {
	    statedata.replaceChild(exception,nl.item(0));
	} else {
	    statedata.appendChild(exception);
	}

	//XMLCommon.debugXML(root);
    }

    /**
     * We need to synchronize that to avoid problems, but this should be fast anyway 
     */
    public synchronized void setStateVar(String name, String value) {
	Element var=XMLCommon.getElementByAttribute(statedata,"VAR","name",name);
	if(var == null) {
	    var=root.createElement("VAR");
	    var.setAttribute("name",name);
	    statedata.appendChild(var);
	}
	var.setAttribute("value",value);
    }

    public Element createStateVar(String name, String value) {
	Element var=root.createElement("VAR");
	var.setAttribute("name",name);
	var.setAttribute("value",value);
	return var;
    }

    public void addStateVar(String name, String value) {
	Element var=root.createElement("VAR");
	var.setAttribute("name",name);
	statedata.appendChild(var);
	var.setAttribute("value",value);
    }

    /**
     * We need to synchronize that because it can cause problems with multiple threads
     */
    public synchronized void removeAllStateVars(String name) {
	NodeList nl=statedata.getElementsByTagName("VAR");

	/* This suxx: NodeList Object is changed when removing children !!!
	   I will store all nodes that should be deleted in a Vector and delete them afterwards */
	int length=nl.getLength();
	Vector v=new Vector(nl.getLength());
	for(int i=0;i<length;i++) {	    
	    if(((Element)nl.item(i)).getAttribute("name").equals(name)) {	
		v.addElement(nl.item(i));
	    }
	}
	Enumeration enum=v.elements();
	while(enum.hasMoreElements()) {
	    Node n=(Node)enum.nextElement();
	    statedata.removeChild(n);
	}
    }
	

    public String getStateVar(String name) {
	Element var=XMLCommon.getElementByAttribute(statedata,"VAR","name",name);
	if(var == null) {
	    return "";
	} else {
	    return var.getAttribute("value");
	}
    }


} // XMLGenericModel