Java tutorial
/* * Copyright 2003-2010 Tufts University Licensed under the * Educational Community License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. You may * obtain a copy of the License at * * http://www.osedu.org/licenses/ECL-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an "AS IS" * BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express * or implied. See the License for the specific language governing * permissions and limitations under the License. */ /* * C abinet.java * * Created on September 17, 2003, 10:04 AM */ package tufts.oki.remoteFiling; import tufts.oki.shared.*; import org.apache.commons.net.ftp.*; import java.io.*; import java.util.*; import osid.OsidException; /** * RemoteCabinet is a implementation of osid.filing.Cabinet which models a remote * directory accessed via FTP. In order to save internal memory space, a cabinet * is not initialized to the entries in it until entries() is called. The add() * method is provided to allow new entries in this directory to be included in its * list of entries. The createCabinet() and createByteStore() methods are used to * create a new directory or new file, respectively. * * @author Mark Norton - OKI compatibility. * @author Salem Berhanu - much of the FTP transactions. * */ public class RemoteCabinet extends RemoteCabinetEntry implements osid.filing.Cabinet { /* parent is inherited from Cabinet Entry. */ Vector children = null; tufts.oki.shared.Properties properties = null; private boolean initialized = false; //private boolean open = false; //private File dir = null; // The remote directory being modeled. /** * Initializes the feilds interited from CabinetEntry and adds a vector of children. * Creates a Properties object to hold properties associated with this cabinet. * * @author Mark Norton * */ public RemoteCabinet(String displayName, osid.shared.Agent agentOwner, osid.filing.Cabinet parent, RemoteClient rc) { super(displayName, agentOwner, parent, rc); children = new Vector(100); //FilingCabinetType type = new FilingCabinetType(); //properties = new osid_mjn.shared.Properties(type); if (parent == null) updateDisplayName(""); else updateDisplayName(displayName); } /** * Add the entry to the list of children. * * @author Mark Norton */ public void add(osid.filing.CabinetEntry entry, java.lang.String name) throws osid.filing.FilingException { /* Update the display name in entry with name. Does this make sense? */ entry.updateDisplayName(name); /* Add the element to the Vector array. */ children.addElement(entry); } /** * Add the entry to the list of children. * * @author Mark Norton */ public void add(osid.filing.CabinetEntry entry) throws osid.filing.FilingException { /* Add the element to the Vector array. */ children.addElement(entry); } /* * The oldByteStore is copied into the new ByteStore. * * @author Mark Norton * * @return A new ByteStore with the name provided and this cabinet as parent. */ public osid.filing.ByteStore copyByteStore(String name, osid.filing.ByteStore oldByteStore) throws osid.filing.FilingException { throw new osid.filing.FilingException(osid.filing.FilingException.UNIMPLEMENTED); } /** * Currently unimplemented. A lot depends on the eventual use of the filing * system implemented by these classes. Not all systems will have a restriction * on available and used byes. * * @author Mark Norton * * @return The number of bytes available in this cabinet. */ public long getAvailableBytes() throws osid.filing.FilingException { throw new osid.filing.FilingException(osid.filing.FilingException.UNIMPLEMENTED); } /** * Currently unimplemented. A lot depends on the eventual use of the filing * system implemented by these classes. Not all systems will have a restriction * on available and used byes. * <p> * This could be implemented as the sum of of the sizes of the ByteStores in this * directory, but its not clear what use that would be. * * @author Mark Norton * * @return The number of bytes used in this cabinet. */ public long getUsedBytes() throws osid.filing.FilingException { throw new osid.filing.FilingException(osid.filing.FilingException.UNIMPLEMENTED); } /** * Create a new ByteStore, add it to this Cabinet. * * @author Mark Norton * * @return A new ByteStore with the name provided and this cabinet as parent. */ public osid.filing.ByteStore createByteStore(String name) { osid.filing.ByteStore bs = null; try { bs = new RemoteByteStore(name, this, rc); this.add(bs); } catch (osid.OsidException ex) { } return bs; } /** * Create a new cabinet entry with * the agentOwner of this new cabinet as this owner of this Cabinet. * * @author Mark Norton * * @return A new cabinet with the given displayName. */ public osid.filing.Cabinet createCabinet(String displayName) throws osid.filing.FilingException { // Create the new cabinet entry. osid.shared.Agent agentOwner = super.getCabinetEntryAgent(); RemoteCabinet entry = new RemoteCabinet(displayName, agentOwner, this, rc); // Make a directory on the remote file system. try { FTPClient client = rc.getClient(); if (!client.makeDirectory(entry.getFullName())) throw new osid.filing.FilingException(osid.filing.FilingException.ITEM_ALREADY_EXISTS); } catch (java.io.IOException ex) { throw new osid.filing.FilingException(osid.filing.FilingException.IO_ERROR); } /* Add the element to the Vector array. */ children.addElement(entry); return entry; } /** * Creates an iterator which lists the entries in this cabinet. A check is made to * see if this cabinet was previously opened. If not, it is opened and initialized * with the entries contained in it. * * @author Mark Norton * * @return Return an iterator for the entries in this cabinet. */ public osid.filing.CabinetEntryIterator entries() throws osid.filing.FilingException { // Check to see if this cabinet is unopened. If not, intialize it. if (!initialized) { // Initialize the directory by getting all entries contained in it. FTPFile[] files = null; try { String rootBase = rc.getRootBase(); RemotePath path = new RemotePath(rootBase, this); String pathname = path.getPathString(); //System.out.println("PATHNAME:"+pathname); FTPClient client = rc.getClient(); files = client.listFiles(pathname); // Executes an FTP LIST command. osid.shared.Agent agentOwner = super.getCabinetEntryAgent(); // Iterate over the files returned and create CabinetEntries for them. // Note that there is a lot of other information in the FTPFile objects which // could be added to the entries being created here. In particular, creation // date. for (int i = 0; files != null && i < files.length; i++) { if (files[i].isDirectory()) { //System.out.println ("\tDir " + i + ": " + files[i].getName()); //RemoteCabinet cab = (RemoteCabinet) this.createCabinet (files[i].getName()); add(new RemoteCabinet(files[i].getName(), agentOwner, this, rc)); } else if (files[i].isFile()) { //System.out.println ("\tFile " + i + ": " + files[i].getName()); //RemoteByteStore store = (RemoteByteStore) this.createByteStore (files[i].getName()); add(new RemoteByteStore(files[i].getName(), this, rc)); } // Unknown cases are ignored. } } catch (java.io.IOException ex1) { throw new osid.filing.FilingException(osid.filing.FilingException.IO_ERROR); } // The current working directory is now intialized. initialized = true; } return (osid.filing.CabinetEntryIterator) new RemoteCabinetEntryIterator(children); } /** * Get a cabinet entry given its name. * * @author Mark Norton * * @return The cabinet entry with the desired display name. Throws ITEM_DOES_NOT_EXIST if name is unknown. */ public osid.filing.CabinetEntry getCabinetEntryByName(String name) throws osid.filing.FilingException { for (int i = 0; i < children.size(); i++) { RemoteCabinetEntry entry = (RemoteCabinetEntry) children.elementAt(i); if (name.compareTo(entry.getDisplayName()) == 0) { return (osid.filing.CabinetEntry) entry; } } /* ITEM_DOES_NOT_EXIST is not exactly the right sentiment for not finding the entry. */ throw new osid.filing.FilingException(osid.filing.FilingException.ITEM_DOES_NOT_EXIST); } /** * Get a cabinet entry given its identifier. Throws ITEM_DOES_NOT_EXIST if Id is unknown. * * @author Mark Norton * * @return The cabinet entry corresponding to the identifier passed. */ public osid.filing.CabinetEntry getCabinetEntryById(osid.shared.Id id) throws osid.filing.FilingException { for (int i = 0; i < children.size(); i++) { RemoteCabinetEntry entry = (RemoteCabinetEntry) children.elementAt(i); try { if (id.isEqual(entry.getId())) { return (osid.filing.CabinetEntry) entry; } } catch (osid.shared.SharedException ex) { /* Not exactly sure what could go wrong with an Id comparison, * but the compiler insists on catching this exception. * This will fall through to ITEM_DOES_NOT_EXIST exception throw. */ } } /* ITEM_DOES_NOT_EXIST is not exactly the right sentiment for not finding the entry. */ throw new osid.filing.FilingException(osid.filing.FilingException.ITEM_DOES_NOT_EXIST); } /** * Return the properties associated with this cabinet as a HashMap. This is better * implmented using the expanded Properties objects defined elsewhere. * * @author Mark Norton * * @return The property set of the Properties object associated with this cabinet as a Map. */ public java.util.Map getProperties() throws osid.filing.FilingException { HashMap map = properties.getPropertySet(); return (Map) map; } /** * Get the root cabinet of this cabinet. * * @author Mark Norton * * @return The root cabinet of this cabinet by searching up the parent links. */ public osid.filing.Cabinet getRootCabinet() throws osid.filing.FilingException { osid.filing.Cabinet cab = this; while (cab.getParent() != null) cab = cab.getParent(); return cab; } /** * Currently, this always returns true, since cabinets are always defined to be * listable. This could be made a property instead. * * @author Mark Norton * * @return True if this cabinet is listable. */ public boolean isListable() throws osid.filing.FilingException { return true; } /** * Currently, this always returns true, since cabinets are defined to be managable * in this implementation. It could be made a property instead. * * @author Mark Norton * * @return True if this cabinet is managable. */ public boolean isManageable() throws osid.filing.FilingException { return true; } /** * Return true if this is a root cabinet, ie., its parent is null. * * @author Mark Norton * * @return True if this is a root cabinet (parent == null). */ public boolean isRootCabinet() throws osid.filing.FilingException { return (this.getParent() == null); } /** * Remove the entry indicated from the children of this cabinet. The entry is * identified by comparing the Ids of the entry passed to the Id of the children * present. This assumes that such Ids are globally unique. * <p> * No error is thrown if entry is not present. * <p> * Note: remove doesn't remove the entry on the remote file system at this time. * * @author Mark Norton */ public void remove(osid.filing.CabinetEntry entry) throws osid.filing.FilingException { osid.shared.Id entry_id = entry.getId(); for (int i = 0; i < children.size(); i++) { RemoteCabinetEntry ent = (RemoteCabinetEntry) children.elementAt(i); try { if (entry_id.isEqual(ent.getId())) { children.remove(entry); } } catch (osid.shared.SharedException ex) { /* Unlikely that isEqual() will throw a SharedException. */ } } } /** * Return the number of children this cabinent has. * <p> * This is an extension to osid.filing.Cabinet to support classes which imlement * javax.swing.tree.TreeModel. * * @author Mark Norton * * @return the number of children in this cabinet. */ public int getChildCount() { return children.size(); } /** * Check to see if this cabinet is initialized. * * @author Mark Norton * * @return true if the cabinet is initialized. */ public boolean isInitialized() { return this.initialized; } /** * Set the initialized flag to the value given. * * @author Mark Norton */ public void setInitialized(boolean flag) { this.initialized = flag; } /** * Get the full file name for this entry, including path to local root. * <p> * Warning! This name cannot be used to open local files, since it does * not include rootBase. The absolute name can be created by concatenating * rootBase and getFullName(). * * @author Mark Norton */ public String getFullName() { StringBuffer fn = new StringBuffer(rc.getRootBase()); fn = new StringBuffer(); ArrayList parts = new ArrayList(100); // Walk path to root. RemoteCabinet ptr = this; while (ptr.getParent() != null) { parts.add(0, ptr.getDisplayName()); ptr = (RemoteCabinet) ptr.getParent(); } // Add intermediate path to file name. for (int i = 0; i < parts.size(); i++) { fn.append("/" + parts.get(i)); } // Add the final file name. // fn.append("/" + getDisplayName()); //:REMOVED not needed return fn.toString(); } /** * Rename the file corresponding to this cabinet and update it's display * name to the new name. * * @author Mark Norton */ public void rename(String newName) throws osid.filing.FilingException { // Check the name of the directory on the remote file system. try { FTPClient client = rc.getClient(); if (getParent() == null) client.rename(getFullName(), rc.getRootBase() + "/" + newName); else client.rename(getFullName(), ((RemoteCabinet) getParent()).getFullName() + "/" + newName); } catch (java.io.IOException ex) { throw new osid.filing.FilingException(osid.filing.FilingException.IO_ERROR); } // Change the name of the Cabinet. updateDisplayName(newName); } public String getUrl() { String url = "ftp://" + rc.getUserName() + ":" + rc.getPassword() + "@" + rc.getServerName() + this.getFullName(); //System.out.println("CABINET URL:"+ url); return url; } }