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The source code

/*
 *                 Sun Public License Notice
 * 
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 * 
 * The Original Code is NetBeans. The Initial Developer of the Original
 * Code is Sun Microsystems, Inc. Portions Copyright 1997-2004 Sun
 * Microsystems, Inc. All Rights Reserved.
 */

package org.netbeans.modules.db.explorer.driver;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.lang.ref.Reference;
import java.lang.ref.WeakReference;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.LinkedList;

import org.openide.ErrorManager;
import org.openide.cookies.InstanceCookie;
import org.openide.filesystems.FileLock;
import org.openide.filesystems.FileObject;
import org.openide.filesystems.FileSystem;
import org.openide.filesystems.FileUtil;
import org.openide.loaders.Environment;
import org.openide.loaders.DataFolder;
import org.openide.loaders.DataObject;
import org.openide.loaders.MultiDataObject;
import org.openide.loaders.XMLDataObject;
import org.openide.nodes.Node;
import org.openide.util.RequestProcessor;
import org.openide.util.Lookup;
import org.openide.util.lookup.AbstractLookup;
import org.openide.util.lookup.InstanceContent;
import org.openide.xml.EntityCatalog;
import org.openide.xml.XMLUtil;

import org.openide.filesystems.Repository;

import org.xml.sax.InputSource;
import org.xml.sax.XMLReader;
import org.xml.sax.SAXException;

/**
 * Reads and writes the standard JDBC driver registration format.
 */
public class JDBCDriverConvertor implements Environment.Provider, InstanceCookie.Of, PropertyChangeListener, Runnable, InstanceContent.Convertor {
    
    private JDBCDriverConvertor() {}

    public static JDBCDriverConvertor createProvider(FileObject reg) {
        fo = reg;
        return new JDBCDriverConvertor();
    }
    
    public Lookup getEnvironment(DataObject obj) {
        return new JDBCDriverConvertor((XMLDataObject) obj).getLookup();
    }
    
    InstanceContent cookies = new InstanceContent();
    
    XMLDataObject holder;
    static FileObject fo;
    
    Lookup lookup;
    
    RequestProcessor.Task saveTask;
    
    Reference refDriver = new WeakReference(null);
    
    LinkedList keepAlive = new LinkedList();
    
    private JDBCDriverConvertor(XMLDataObject object) {
        this.holder = object;
        cookies = new InstanceContent();
        cookies.add(this);
        lookup = new AbstractLookup(cookies);
        cookies.add(Node.class, this);
    }
    
    Lookup getLookup() {
        return lookup;
    }
    
    public Class instanceClass() {
        return JDBCDriver.class;
    }
    
    public Object instanceCreate() throws java.io.IOException, ClassNotFoundException {
        synchronized (this) {
            Object o = refDriver.get();
            if (o != null)
                return o;
            H handler = new H();
            try {
                XMLReader reader = XMLUtil.createXMLReader();
                if (holder == null)
                    holder = (XMLDataObject) DataObject.find(fo);
                InputSource is = new org.xml.sax.InputSource(holder.getPrimaryFile().getInputStream());
                is.setSystemId(holder.getPrimaryFile().getURL().toExternalForm());
                reader.setContentHandler(handler);
                reader.setErrorHandler(handler);
                reader.setEntityResolver(EntityCatalog.getDefault());

                reader.parse(is);
            } catch (SAXException ex) {
                Exception x = ex.getException();
                ex.printStackTrace();
                if (x instanceof java.io.IOException)
                    throw (IOException)x;
                else
                    throw new java.io.IOException(ex.getMessage());
            }

            JDBCDriver inst = createDriver(handler);
            refDriver = new WeakReference(inst);
            return inst;
        }
    }
    
    JDBCDriver createDriver(H handler) {
        URL[] urls;
        LinkedList urlList = new LinkedList();
        for (int i = 0; i < handler.urls.size(); i++)
            try {
                urlList.add(new URL((String) handler.urls.get(i)));
            } catch (MalformedURLException exc) {
                //PENDING
            }
        urls = (URL[]) urlList.toArray(new URL[urlList.size()]);
        JDBCDriver d = new JDBCDriver(handler.name, handler.clazz, urls);

        d.addPropertyChangeListener(this);
        return d;
    }
    
    public String instanceName() {
        return holder.getName();
    }
    
    public boolean instanceOf(Class type) {
        return (type.isAssignableFrom(JDBCDriver.class));
    }
    
    public FileObject instanceOrigin() {
        return holder.getPrimaryFile();
    }
    
    static int DELAY = 2000;
    
    public void propertyChange(PropertyChangeEvent evt) {
        synchronized (this) {
            if (saveTask == null)
                saveTask = RequestProcessor.getDefault().create(this);
        }
        synchronized (this) {
            keepAlive.add(evt);
        }
        saveTask.schedule(DELAY);
    }
    
    public void run() {
        PropertyChangeEvent e;
        
        synchronized (this) {
            e = (PropertyChangeEvent)keepAlive.removeFirst();
        }
        JDBCDriver drv = (JDBCDriver) e.getSource();
        try {
            holder.getPrimaryFile().getFileSystem().runAtomicAction(new W(drv, holder));
        } catch (IOException ex) {
            ErrorManager.getDefault().notify(ErrorManager.INFORMATIONAL, ex);
        }
    }
    
    public Object convert(Object obj) {
        if (obj == Node.class) {
            Object drv;
            
            try {
                drv = instanceCreate();
            } catch (IOException ex) {
                ex.printStackTrace();
                return null;
            } catch (ClassNotFoundException ex) {
                return null;
            } catch (Exception ex) {
                ex.printStackTrace();
                return null;
            }
//            return new LookNode(drv, null, Looks.defaultSelector());
            return null;
        } else
            return null;
    }
    
    public String displayName(Object obj) {
        return ((Class)obj).getName();
    }
    
    public String id(Object obj) {
        return obj.toString();
    }
    
    public Class type(Object obj) {
        return (Class)obj;
    }
    
//    public static DataObject create(JDBCDriver drv, DataFolder f, String idName) throws IOException {
    public static DataObject create(JDBCDriver drv) throws IOException {
        FileObject fo = Repository.getDefault().getDefaultFileSystem().findResource("Services/JDBCDrivers");
        DataFolder df = DataFolder.findFolder(fo);
        
//        W w = new W(drv, df, drv.getName());
        String fileName = drv.getClassName().replace('.', '_'); //NOI18N
        W w = new W(drv, df, fileName);
        df.getPrimaryFile().getFileSystem().runAtomicAction(w);
        return w.holder;
    }
    
    static class W implements FileSystem.AtomicAction {
        JDBCDriver instance;
        MultiDataObject holder;
        String name;
        DataFolder f;
        
        W(JDBCDriver instance, MultiDataObject holder) {
            this.instance = instance;
            this.holder = holder;
        }
        
        W(JDBCDriver instance, DataFolder f, String n) {
            this.instance = instance;
            this.name = n;
            this.f = f;
        }
        
        public void run() throws java.io.IOException {
            FileLock lck;
            FileObject data;
            
            if (holder != null) {
                data = holder.getPrimaryEntry().getFile();
                lck = holder.getPrimaryEntry().takeLock();
            } else {
                FileObject folder = f.getPrimaryFile();
                String fn = FileUtil.findFreeFileName(folder, name, "xml"); //NOI18N
                data = folder.createData(fn, "xml"); //NOI18N
                lck = data.lock();
            }
            
            try {
                OutputStream ostm = data.getOutputStream(lck);
                PrintWriter writer = new PrintWriter(new OutputStreamWriter(ostm, "UTF8")); //NOI18N
                write(writer);
                writer.flush();
                writer.close();
                ostm.close();
            } finally {
                lck.releaseLock();
            }
            
            if (holder == null)
                holder = (MultiDataObject)DataObject.find(data);
        }
        
        void write(PrintWriter pw) throws IOException {
            pw.println(""); //NOI18N
            pw.println(""); //NOI18N
            pw.println(""); //NOI18N
            pw.println("  "); //NOI18N
            pw.println("  "); //NOI18N
            pw.println("  "); //NOI18N
            URL[] urls = instance.getURLs();
            for (int i = 0; i < urls.length; i++)
                pw.println("    "); //NOI18N
            pw.println("  "); //NOI18N
            pw.println(""); //NOI18N
        }
    }
    
    static final String ELEMENT_NAME = "name"; // NOI18N
    static final String ELEMENT_CLASS = "class"; // NOI18N
    static final String ELEMENT_URL = "url"; // NOI18N
    static final String ATTR_PROPERTY_VALUE = "value"; // NOI18N
    
    static class H extends org.xml.sax.helpers.DefaultHandler {
        String name;
        String clazz;
        LinkedList urls = new LinkedList();
        
        public void startDocument () throws org.xml.sax.SAXException {
        }
        
        public void endDocument () throws org.xml.sax.SAXException {
        }
        
        public void startElement (String uri, String localName, String qName, org.xml.sax.Attributes attrs) throws org.xml.sax.SAXException {
            if (ELEMENT_NAME.equals(qName))
                name = attrs.getValue(ATTR_PROPERTY_VALUE);
            else if (ELEMENT_CLASS.equals(qName))
                clazz = attrs.getValue(ATTR_PROPERTY_VALUE);
            else if (ELEMENT_URL.equals(qName))
                urls.add(attrs.getValue(ATTR_PROPERTY_VALUE));
        }
    }
}
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