org.openide.loaders.DataLoader Maven / Gradle / Ivy
/*
* 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 1997-2000 Sun
* Microsystems, Inc. All Rights Reserved.
*/
package org.openide.loaders;
import java.beans.*;
import java.io.*;
import java.util.*;
import org.openide.ErrorManager;
import org.openide.filesystems.*;
import org.openide.nodes.NodeOp;
import org.openide.util.Lookup;
import org.openide.util.NbBundle;
import org.openide.util.SharedClassObject;
import org.openide.util.Utilities;
import org.openide.util.actions.SystemAction;
import org.openide.util.io.SafeException;
/** A data loader recognizes {@link FileObject}s and creates appropriate
* {@link DataObject}s to represent them.
* The created data object must be a subclass
* of the representation class provided in the constructor.
*
* Subclasses of DataLoader should be made JavaBeans with
* additional parameters, so a user may configure the loaders in the loader pool.
*
* @author Jaroslav Tulach
*/
public abstract class DataLoader extends SharedClassObject {
// XXX why is this necessary? otherwise reading loader pool now throws heavy
// InvalidClassException's reading (abstract!) DataLoader...? --jglick
private static final long serialVersionUID = 1986614061378346169L;
/** property name of display name */
public static final String PROP_DISPLAY_NAME = "displayName"; // NOI18N
/** property name of list of actions */
public static final String PROP_ACTIONS = "actions"; // NOI18N
/** property name of list of default actions */
private static final String PROP_DEF_ACTIONS = "defaultActions"; // NOI18N
/** representation class, not public property */
private static final Object PROP_REPRESENTATION_CLASS = new Object ();
/** representation class name, not public property */
private static final Object PROP_REPRESENTATION_CLASS_NAME = new Object ();
private static final int LOADER_VERSION = 1;
/** Create a new data loader.
* Pass its representation class as a parameter to the constructor.
* It is recommended that representation class is superclass of all
* DataObjects produced by the loaded, but it is not required any more.
*
* @param representationClass the superclass (not necessarily) of all objects
* returned from {@link #findDataObject}. The class may be anything but
* should be chosen to be as close as possible to the actual class of objects returned from the loader,
* to best identify the loader's data objects to listeners.
* @deprecated Use {@link #DataLoader(String)} instead.
*/
protected DataLoader (Class representationClass) {
putProperty (PROP_REPRESENTATION_CLASS, representationClass);
putProperty (PROP_REPRESENTATION_CLASS_NAME, representationClass.getName());
if (representationClass.getClassLoader() == getClass().getClassLoader()) {
ErrorManager.getDefault().log(ErrorManager.WARNING, "Use of super(" + representationClass.getName() + ".class) in " + getClass().getName() + "() should be replaced with super(\"" + representationClass.getName() + "\") to reduce unnecessary class loading");
}
}
/** Create a new data loader.
* Pass its representation class name
* as a parameter to the constructor. The constructor is then allowed
* to return only subclasses of the representation class as the result of
* {@link #findDataObject}.
*
* @param representationClassName the name of the superclass for all objects
* returned from
* {@link #findDataObject}. The class may be anything but
* should be chosen to be as close as possible to the actual class of objects returned from the loader,
* to best identify the loader's data objects to listeners.
*
* @since 1.10
*/
protected DataLoader( String representationClassName ) {
putProperty (PROP_REPRESENTATION_CLASS_NAME, representationClassName);
}
/**
* Get the representation class for this data loader, as passed to the constructor.
* @return the representation class
*/
public final Class getRepresentationClass() {
Class cls = (Class)getProperty (PROP_REPRESENTATION_CLASS);
if (cls != null) return cls;
String clsName = (String)getProperty (PROP_REPRESENTATION_CLASS_NAME);
try {
cls = Class.forName (clsName, false, getClass().getClassLoader ());
} catch (ClassNotFoundException cnfe) {
throw new IllegalStateException (cnfe.toString ());
}
putProperty (PROP_REPRESENTATION_CLASS, cls);
return cls;
}
/**
* Get the name of the representation class for this data loader.
* Might avoid actually loading the class.
* @return the class name
* @see #getRepresentationClass
* @since 3.25
*/
public final String getRepresentationClassName() {
return (String)getProperty (PROP_REPRESENTATION_CLASS_NAME);
}
/** Get actions.
* These actions are used to compose
* a popup menu for the data object. Also these actions should
* be customizable by the user, so he can modify the popup menu on a
* data object.
*
* @return array of system actions or null if this loader does not have any
* actions
*/
public final SystemAction[] getActions () {
SystemAction[] actions = (SystemAction[])getProperty (PROP_ACTIONS);
if ( actions == null ) {
actions = (SystemAction[])getProperty (PROP_DEF_ACTIONS);
if ( actions == null ) {
actions = defaultActions();
putProperty (PROP_DEF_ACTIONS, actions, false);
}
}
return actions;
}
/** Get default actions.
* @return array of default system actions or null if this loader
* does not have any actions.
* Typical example of usage:
*
* return new SystemAction[] {
* SystemAction.get (OpenAction.class), ...
* SystemAction.get (PropertiesAction.class)
* };
*
*/
protected SystemAction[] defaultActions () {
SystemAction[] actions = NodeOp.getDefaultActions();
return actions;
}
/** Set actions.
* Note that this method is public, not protected, so it is possible for anyone
* to modify the loader's popup actions externally (after finding the loader
* using {@link DataLoaderPool#firstProducerOf}).
* While this is possible, anyone doing so must take care to place new actions
* into sensible positions, including consideration of separators.
* This may also adversely affect the intended feel of the data objects.
* A preferable solution is generally to use {@link org.openide.actions.ToolsAction service actions}.
* @param actions actions for this loader or null if it should not have any
* @see #getActions
*/
public final void setActions (SystemAction[] actions) {
putProperty (PROP_ACTIONS, actions, true);
}
/** Get the current display name of this loader.
* @return display name
*/
public final String getDisplayName () {
String dn = (String) getProperty (PROP_DISPLAY_NAME);
if (dn != null) {
return dn;
} else {
dn = defaultDisplayName();
if (dn != null) {
return dn;
} else {
return getRepresentationClassName();
}
}
}
/** Set the display name for this loader. Only subclasses should set the name.
* @param displayName new name
*/
protected final void setDisplayName (final String displayName) {
putProperty (PROP_DISPLAY_NAME, displayName, true);
}
/** Get the default display name of this loader.
* @return default display name
*/
protected String defaultDisplayName () {
return NbBundle.getBundle(DataLoader.class).getString ("LBL_loader_display_name");
}
/** Find a data object appropriate to the given file object--the meat of this class.
*
* For example: for files with the same basename but extensions .java and .class, the handler
* should return the same DataObject.
*
* The loader can add all files it has recognized into the recognized
* buffer. Then all these files will be excluded from further processing.
*
* @param fo file object to recognize
* @param recognized recognized file buffer
* @exception DataObjectExistsException if the data object for the
* primary file already exists
* @exception IOException if the object is recognized but cannot be created
* @exception InvalidClassException if the class is not instance of
* {@link #getRepresentationClass}
*
* @return suitable data object or null if the handler cannot
* recognize this object (or its group)
* @see #handleFindDataObject
*/
public final DataObject findDataObject (
FileObject fo, RecognizedFiles recognized
) throws IOException {
try {
return DataObjectPool.handleFindDataObject( this, fo, recognized );
} catch (IOException ioe) {
throw ioe;
} catch (ThreadDeath td) {
throw td;
} catch (RuntimeException e) {
// Some strange error, perhaps an unexpected exception in
// MultiFileLoader.findPrimaryFile. Such an error ought
// not cause whole folder recognizer to die! Assume that
// file/loader is kaput and continue.
IOException ioe = new IOException (e.toString());
ErrorManager.getDefault ().annotate (ioe, e);
throw ioe;
}
/*
if (obj != null && !getRepresentationClass ().isInstance (obj)) {
// does not fullfil representation class
throw new java.io.InvalidClassException (obj.getClass ().toString ());
}
return obj;
*/
}
/** Find a data object appropriate to the given file object (as implemented in subclasses).
* @see #findDataObject
* @param fo file object to recognize
* @param recognized recognized file buffer
* @exception DataObjectExistsException as in #findDataObject
* @exception IOException as in #findDataObject
*
* @return the data object or null
*/
protected abstract DataObject handleFindDataObject (
FileObject fo, RecognizedFiles recognized
) throws IOException;
/** Utility method to mark a file as belonging to this loader.
* When the file is to be recognized this loader will be used first.
*
* This method is used by {@link DataObject#markFiles}.
*
* @param fo file to mark
* @exception IOException if setting the file's attribute failed
*/
public final void markFile (FileObject fo) throws IOException {
DataLoaderPool.setPreferredLoader(fo, this);
}
/** Writes nothing to the stream.
* @param oo ignored
*/
public void writeExternal (ObjectOutput oo) throws IOException {
oo.writeObject( new Integer(LOADER_VERSION) );
SystemAction[] arr = (SystemAction[])getProperty (PROP_ACTIONS);
if (arr == null) {
oo.writeObject (null);
} else {
// convert actions to class names
LinkedList names = new LinkedList ();
for (int i = 0; i < arr.length; i++) {
if (arr[i] == null) {
names.add (null);
} else {
names.add (arr[i].getClass ().getName ());
}
}
oo.writeObject (names.toArray ());
}
String dn = (String) getProperty (PROP_DISPLAY_NAME);
if ( dn == null )
dn = ""; // NOI18N
oo.writeUTF ( dn );
}
/** Reads actions and display name from the stream.
* @param oi input source to read from
* @exception SafeException if some of the actions is not found in the
* stream, but all the content has been read ok. Subclasses can
* catch this exception and continue reading from the stream
*/
public void readExternal (ObjectInput oi)
throws IOException, ClassNotFoundException {
Exception main = null;
int version = 0;
Object first = oi.readObject ();
if ( first instanceof Integer ) {
version = ((Integer)first).intValue();
first = oi.readObject ();
}
// new version that reads the names of the actions - NB3.1
Object[] arr = (Object[])first;
boolean isdefault = true;
SystemAction[] defactions = getActions ();
if ( version > 0 || ( version == 0 && arr.length != defactions.length ))
isdefault = false;
if (arr != null) {
List ll = new ArrayList (arr.length);
for (int i = 0; i < arr.length; i++) {
if (arr[i] == null) {
ll.add (null);
if ( version == 0 && isdefault && defactions[i] != null)
isdefault = false;
continue;
}
try {
Class c = Class.forName (
Utilities.translate((String)arr[i]),
false, // why resolve?? --jglick
(ClassLoader)Lookup.getDefault().lookup(ClassLoader.class)
);
SystemAction ac = SystemAction.get (c);
ll.add (ac);
if ( version == 0 && isdefault && !defactions[i].equals(ac))
isdefault = false;
} catch (ClassNotFoundException ex) {
ErrorManager.getDefault ().annotate (
ex, org.openide.ErrorManager.INFORMATIONAL,
null, null, null, null
);
if (main == null) {
main = ex;
} else {
ErrorManager.getDefault ().annotate (main, ex);
}
}
}
if (main == null && !isdefault) {
// Whole action list was successfully read.
setActions ((SystemAction[])ll.toArray(new SystemAction[ll.size()]));
} // Else do not try to override the default action list if it is incomplete anyway.
}
String displayName = oi.readUTF ();
if ( displayName.equals("") || ( version == 0 && displayName.equals(defaultDisplayName()))) // NOI18N
displayName = null;
setDisplayName( displayName );
if (main != null) {
// exception occured during reading
SafeException se = new SafeException (main);
// Provide a localized message explaining that there is no big problem.
String message = NbBundle.getMessage (DataLoader.class, "EXC_missing_actions_in_loader", getDisplayName ());
ErrorManager.getDefault ().annotate (se, message);
throw se;
}
}
protected boolean clearSharedData () {
return false;
}
/** Get a registered loader from the pool.
* @param loaderClass exact class of the loader (not its data object representation class)
* @return the loader instance, or null if there is no such loader registered
* @see DataLoaderPool#allLoaders
*/
public static DataLoader getLoader (Class loaderClass) {
return (DataLoader)findObject (loaderClass, true);
}
// XXX huh? --jglick
// The parameter can be null to
// simplify testing whether the file object fo is valid or not
/** Buffer holding a list of primary and secondary files marked as already recognized, to prevent further scanning.
*/
public interface RecognizedFiles {
/** Mark this file as being recognized. It will be excluded
* from further processing.
*
* @param fo file object to exclude
*/
public void markRecognized (FileObject fo);
}
}