bundles/org.eclipse.jst.jsp.core/src/org/eclipse/jst/jsp/core/internal/java/JSPTranslatorPersister.java - sourceediting/webtools.sourceediting - Git at Google

 /*******************************************************************************
  * Copyright (c) 2010 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.jst.jsp.core.internal.java;

 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InvalidClassException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.io.UnsupportedEncodingException;
 import java.util.zip.CRC32;

 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.jst.jsp.core.internal.JSPCorePlugin;
 import org.eclipse.jst.jsp.core.internal.Logger;
 import org.eclipse.jst.jsp.core.internal.java.search.JSPIndexManager;
 import org.eclipse.jst.jsp.core.internal.modelhandler.ModelHandlerForJSP;
 import org.eclipse.wst.sse.core.StructuredModelManager;
 import org.eclipse.wst.sse.core.internal.FileBufferModelManager;
 import org.eclipse.wst.sse.core.internal.provisional.IStructuredModel;
 import org.eclipse.wst.xml.core.internal.provisional.document.IDOMDocument;
 import org.eclipse.wst.xml.core.internal.provisional.document.IDOMModel;

 /**
  * <p>This is a static class used to persist JSP translations and retrieve the persisted
  * translations.</p>
  *
  * <p>It is not actually in charge of finding files to persist, rather it provides API
  * for some other mechanism that tracks JSP files to call into to persist the translations.</p>
  *
  * <p>This class can be deactivated through the <code>persistJSPTranslations</code> system property,
  * a value of <code>true</code> means the persister is activated (which is the default), value of
  * <code>false</code> means the persister is not activated.</p>
  *
  * @see JSPIndexManager
  */
 public class JSPTranslatorPersister{
 	/**
 	 * <code>true</code> if the persister is activated, <code>false</code>
 	 * otherwise.  This is determined by checking the system property
 	 * <code>persistJSPTranslations</code>, if no value supplied then
 	 * default is <code>true</code>
 	 */
 	public static final boolean ACTIVATED =
 		Boolean.valueOf(System.getProperty("persistJSPTranslations", "true")).booleanValue(); //$NON-NLS-1$ //$NON-NLS-2$

 	/** the location where {@link JSPTranslator}s are externalized too for persistence purposes */
 	private static final IPath PERSIST_LOCATION = JSPCorePlugin.getDefault().getStateLocation().append("translators"); //$NON-NLS-1$

 	/** used to calculate persisted translator file names */
 	private static final CRC32 CHECKSUM_CALC = new CRC32();

 	/** lock to use while using the checksum */
 	private static final Object CHECKSUM_CALC_LOCK = new Object();

 	/**
 	 * <p>Private constructor to prevent creating an instance of this class</p>
 	 */
 	private JSPTranslatorPersister() {
 	}

 	/**
 	 * <p>Given the {@link IStructuredModel} of a JSP file attempts to retrieve the persisted
 	 * {@link JSPTranslator} for that model.</p>
 	 * <p><b>NOTE: </b><i>It is possible for there not to be a persisted translator</i></p>
 	 *
 	 * @param model {@link IStructuredModel} to get the persisted {@link JSPTranslator} for
 	 * @return the persisted {@link JSPTranslator} for the given <code>model</code>, or
 	 * <code>null</code> if none could be found or an existing one could not be read
 	 */
 	public static JSPTranslator getPersistedTranslator(IStructuredModel model) {
 		String persistedTranslatorFilePath = getPersistedTranslatorFilePath(model.getBaseLocation());
 		File persistedTranslatorFile = new File(persistedTranslatorFilePath);

 		//attempt to read in the externalized translator
 		JSPTranslator translator = null;
 		ObjectInputStream in = null;
 		try {
 			//get the persisted translator file if one exists
 			if(persistedTranslatorFile.exists()) {
 				long persistedTranslatorFileTimestamp = persistedTranslatorFile.lastModified();
 				long jspFileTimestamp = FileBufferModelManager.getInstance().getBuffer(
 						model.getStructuredDocument()).getModificationStamp();

 				/* if the persisted translator timestamp is newer then the jsp file timestamp
 				 * then the translation has not become stale, otherwise it has so delete
 				 * it and don't use it */
 				if(persistedTranslatorFileTimestamp > jspFileTimestamp) {
 					FileInputStream fis = new FileInputStream(persistedTranslatorFile);
 					in = new ObjectInputStream(fis);
 					translator = (JSPTranslator)in.readObject();

 					//do post read external setup
 					if(translator != null) {
 						translator.postReadExternalSetup(model);
 					}
 				} else {
 					persistedTranslatorFile.delete();
 				}
 			}
 		} catch(InvalidClassException e) {
 			/* this means that the externalized translator is for an older version
 			 * of the JSPTranslator, so delete it */
 			persistedTranslatorFile.delete();
 		}catch (IOException e) {
 			Logger.logException("Could not read externalized JSPTranslator at " + persistedTranslatorFilePath, e); //$NON-NLS-1$
 		} catch (ClassNotFoundException e) {
 			Logger.logException("Class of a serialized JSPTranslator cannot be found", e); //$NON-NLS-1$
 		} finally {
 			if(in != null) {
 				try {
 					in.close();
 				} catch (IOException e) {
 					Logger.logException("Could not close externalized JSPTranslator that was just read", e); //$NON-NLS-1$
 				}
 			}
 		}

 		return translator;
 	}

 	/**
 	 * @param resource JSP resource who's translation should be persisted
 	 */
 	public static void persistTranslation(IResource resource) {
 		if(ACTIVATED) {
 			IPath path = resource.getFullPath();
 			String filePath = getPersistedTranslatorFilePath(path.toString());
 			IFile file = ResourcesPlugin.getWorkspace().getRoot().getFile(path);

 			JSPTranslator translator = getJSPTranslator(file);
 			if(translator != null) {
 				persistTranslator(translator, filePath);
 			}
 		}
 	}

 	/**
 	 * @param resource JSP resource who's translation should no longer be persisted
 	 */
 	public static void removePersistedTranslation(IResource resource) {
 		if(ACTIVATED) {
 			File file = getPersistedFile(resource.getFullPath());
 			file.delete();
 		}
 	}

 	/**
 	 * @param resource JSP resource that has moved and thus its persisted translation should be updated
 	 * @param fromPath Path the JSP resource moved from
 	 */
 	public static void movePersistedTranslation(IResource resource, IPath fromPath) {
 		if(ACTIVATED) {
 			File from = getPersistedFile(fromPath);
 			File to = getPersistedFile(resource.getFullPath());

 			from.renameTo(to);
 		}
 	}

 	/**
 	 * <p>Given the path to a JSP file determines the path to its persisted {@link JSPTranslator}</p>
 	 *
 	 * @param jspFilePath {@link IPath} to JSP file for which the path to its persisted {@link JSPTranslator}
 	 * should be determined
 	 *
 	 * @return OS file path to the persisted {@link JSPTranslator} associated with the JSP file at
 	 * <code>jspFilePath</code>
 	 */
 	private static String getPersistedTranslatorFilePath(String jspFilePath) {
 		String persistedTranslatorFileName = "error.translator"; //$NON-NLS-1$
 		synchronized(CHECKSUM_CALC_LOCK){
 			try {
 				CHECKSUM_CALC.reset();
 				CHECKSUM_CALC.update(jspFilePath.getBytes("utf16")); //$NON-NLS-1$
 				persistedTranslatorFileName = Long.toString(CHECKSUM_CALC.getValue()) + ".translator"; //$NON-NLS-1$
 			} catch (UnsupportedEncodingException e) {
 				Logger.logException("Could not get utf16 encoded bytes to create checksum to store persisted file.", e); //$NON-NLS-1$
 			}
 		}

 		IPath location = PERSIST_LOCATION;

 		// ensure the folder exists on disk
         File folder = new File(location.toOSString());
 		if (!folder.isDirectory()) {
 			try {
 				folder.mkdir();
 			}
 			catch (SecurityException e) {
 			}
 		}

 		location = location.addTrailingSeparator();
 		location = location.append(persistedTranslatorFileName);
 		return location.toOSString();
 	}

 	/**
 	 * <p>Gets the associated {@link JSPTranslator} for a specific JSP file.</p>
 	 * <p><b>NOTE: </b><i>This does not get the persisted translator but rather the
 	 * associated translator in memory</i></p>
 	 *
 	 * @param jspFile {@link IFile} to the JSP file that the associated {@link JSPTranslator}
 	 * is needed for
 	 * @return {@link JSPTranslator} associated with the given <code>jspFilePath</code>, or
 	 * <code>null</code> if none can be found.
 	 */
 	private static JSPTranslator getJSPTranslator(IFile jspFile) {
 		IStructuredModel model = null;
 		JSPTranslator translator = null;
 		try {
 			model = StructuredModelManager.getModelManager().getModelForRead(jspFile);
 			if(model instanceof IDOMModel) {
 				IDOMDocument doc = ((IDOMModel)model).getDocument();
 				ModelHandlerForJSP.ensureTranslationAdapterFactory(model);
 				JSPTranslationAdapter adapter = (JSPTranslationAdapter)doc.getAdapterFor(IJSPTranslation.class);

 				//don't want to persist a translator that has not already been requested
 				if(adapter != null && adapter.hasTranslation()) {
 					translator = adapter.getJSPTranslation().getTranslator();
 				}
 			}
 		} catch (IOException e) {
 			Logger.logException("Could not get translator for " + jspFile.getName() + //$NON-NLS-1$
 					" because could not read model for same.", e); //$NON-NLS-1$
 		} catch (CoreException e) {
 			Logger.logException("Could not get translator for " + jspFile.getName() + //$NON-NLS-1$
 					" because could not read model for same.", e); //$NON-NLS-1$
 		} finally {
 			if(model != null) {
 				model.releaseFromRead();
 			}
 		}

 		return translator;
 	}

 	/**
 	 * <p>Persists a {@link JSPTranslator} to disk for a specific JSP file</p>
 	 *
 	 * @param translator {@link JSPTranslator} to persist to disk
 	 * @param jspFilePath {@link IPath} to the JSP file the given <code>translator</code> is for
 	 */
 	private static void persistTranslator(JSPTranslator translator, String filePath) {
 		try {
 			FileOutputStream fos = new FileOutputStream(filePath);
 			ObjectOutputStream out = new ObjectOutputStream(fos);
 			out.writeObject(translator);
 			out.close();
 		} catch (IOException e) {
 			Logger.logException("Was unable to externalize JSPTranslator " + translator + //$NON-NLS-1$
 					" to " + filePath, e); //$NON-NLS-1$
 		}
 	}

 	/**
 	 * @param path {@link IPath} to the JSP file that the persisted translator is needed for
 	 * @return The persisted translator {@link File} for the JSP file at the given path
 	 * or <code>null</code> if no persisted translator exists for the JSP file at the given path
 	 */
 	private static File getPersistedFile(IPath path) {
 		return new File(getPersistedTranslatorFilePath(path.toString()));
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2010 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.jst.jsp.core.internal.java;

	import java.io.File;
	import java.io.FileInputStream;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.io.InvalidClassException;
	import java.io.ObjectInputStream;
	import java.io.ObjectOutputStream;
	import java.io.UnsupportedEncodingException;
	import java.util.zip.CRC32;

	import org.eclipse.core.resources.IFile;
	import org.eclipse.core.resources.IResource;
	import org.eclipse.core.resources.ResourcesPlugin;
	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IPath;
	import org.eclipse.jst.jsp.core.internal.JSPCorePlugin;
	import org.eclipse.jst.jsp.core.internal.Logger;
	import org.eclipse.jst.jsp.core.internal.java.search.JSPIndexManager;
	import org.eclipse.jst.jsp.core.internal.modelhandler.ModelHandlerForJSP;
	import org.eclipse.wst.sse.core.StructuredModelManager;
	import org.eclipse.wst.sse.core.internal.FileBufferModelManager;
	import org.eclipse.wst.sse.core.internal.provisional.IStructuredModel;
	import org.eclipse.wst.xml.core.internal.provisional.document.IDOMDocument;
	import org.eclipse.wst.xml.core.internal.provisional.document.IDOMModel;

	/**
	* <p>This is a static class used to persist JSP translations and retrieve the persisted
	* translations.</p>
	*
	* <p>It is not actually in charge of finding files to persist, rather it provides API
	* for some other mechanism that tracks JSP files to call into to persist the translations.</p>
	*
	* <p>This class can be deactivated through the <code>persistJSPTranslations</code> system property,
	* a value of <code>true</code> means the persister is activated (which is the default), value of
	* <code>false</code> means the persister is not activated.</p>
	*
	* @see JSPIndexManager
	*/
	public class JSPTranslatorPersister{
	/**
	* <code>true</code> if the persister is activated, <code>false</code>
	* otherwise. This is determined by checking the system property
	* <code>persistJSPTranslations</code>, if no value supplied then
	* default is <code>true</code>
	*/
	public static final boolean ACTIVATED =
	Boolean.valueOf(System.getProperty("persistJSPTranslations", "true")).booleanValue(); //$NON-NLS-1$ //$NON-NLS-2$

	/** the location where {@link JSPTranslator}s are externalized too for persistence purposes */
	private static final IPath PERSIST_LOCATION = JSPCorePlugin.getDefault().getStateLocation().append("translators"); //$NON-NLS-1$

	/** used to calculate persisted translator file names */
	private static final CRC32 CHECKSUM_CALC = new CRC32();

	/** lock to use while using the checksum */
	private static final Object CHECKSUM_CALC_LOCK = new Object();

	/**
	* <p>Private constructor to prevent creating an instance of this class</p>
	*/
	private JSPTranslatorPersister() {
	}

	/**
	* <p>Given the {@link IStructuredModel} of a JSP file attempts to retrieve the persisted
	* {@link JSPTranslator} for that model.</p>
	* <p><b>NOTE: </b><i>It is possible for there not to be a persisted translator</i></p>
	*
	* @param model {@link IStructuredModel} to get the persisted {@link JSPTranslator} for
	* @return the persisted {@link JSPTranslator} for the given <code>model</code>, or
	* <code>null</code> if none could be found or an existing one could not be read
	*/
	public static JSPTranslator getPersistedTranslator(IStructuredModel model) {
	String persistedTranslatorFilePath = getPersistedTranslatorFilePath(model.getBaseLocation());
	File persistedTranslatorFile = new File(persistedTranslatorFilePath);

	//attempt to read in the externalized translator
	JSPTranslator translator = null;
	ObjectInputStream in = null;
	try {
	//get the persisted translator file if one exists
	if(persistedTranslatorFile.exists()) {
	long persistedTranslatorFileTimestamp = persistedTranslatorFile.lastModified();
	long jspFileTimestamp = FileBufferModelManager.getInstance().getBuffer(
	model.getStructuredDocument()).getModificationStamp();

	/* if the persisted translator timestamp is newer then the jsp file timestamp
	* then the translation has not become stale, otherwise it has so delete
	* it and don't use it */
	if(persistedTranslatorFileTimestamp > jspFileTimestamp) {
	FileInputStream fis = new FileInputStream(persistedTranslatorFile);
	in = new ObjectInputStream(fis);
	translator = (JSPTranslator)in.readObject();

	//do post read external setup
	if(translator != null) {
	translator.postReadExternalSetup(model);
	}
	} else {
	persistedTranslatorFile.delete();
	}
	}
	} catch(InvalidClassException e) {
	/* this means that the externalized translator is for an older version
	* of the JSPTranslator, so delete it */
	persistedTranslatorFile.delete();
	}catch (IOException e) {
	Logger.logException("Could not read externalized JSPTranslator at " + persistedTranslatorFilePath, e); //$NON-NLS-1$
	} catch (ClassNotFoundException e) {
	Logger.logException("Class of a serialized JSPTranslator cannot be found", e); //$NON-NLS-1$
	} finally {
	if(in != null) {
	try {
	in.close();
	} catch (IOException e) {
	Logger.logException("Could not close externalized JSPTranslator that was just read", e); //$NON-NLS-1$
	}
	}
	}

	return translator;
	}

	/**
	* @param resource JSP resource who's translation should be persisted
	*/
	public static void persistTranslation(IResource resource) {
	if(ACTIVATED) {
	IPath path = resource.getFullPath();
	String filePath = getPersistedTranslatorFilePath(path.toString());
	IFile file = ResourcesPlugin.getWorkspace().getRoot().getFile(path);

	JSPTranslator translator = getJSPTranslator(file);
	if(translator != null) {
	persistTranslator(translator, filePath);
	}
	}
	}

	/**
	* @param resource JSP resource who's translation should no longer be persisted
	*/
	public static void removePersistedTranslation(IResource resource) {
	if(ACTIVATED) {
	File file = getPersistedFile(resource.getFullPath());
	file.delete();
	}
	}

	/**
	* @param resource JSP resource that has moved and thus its persisted translation should be updated
	* @param fromPath Path the JSP resource moved from
	*/
	public static void movePersistedTranslation(IResource resource, IPath fromPath) {
	if(ACTIVATED) {
	File from = getPersistedFile(fromPath);
	File to = getPersistedFile(resource.getFullPath());

	from.renameTo(to);
	}
	}

	/**
	* <p>Given the path to a JSP file determines the path to its persisted {@link JSPTranslator}</p>
	*
	* @param jspFilePath {@link IPath} to JSP file for which the path to its persisted {@link JSPTranslator}
	* should be determined
	*
	* @return OS file path to the persisted {@link JSPTranslator} associated with the JSP file at
	* <code>jspFilePath</code>
	*/
	private static String getPersistedTranslatorFilePath(String jspFilePath) {
	String persistedTranslatorFileName = "error.translator"; //$NON-NLS-1$
	synchronized(CHECKSUM_CALC_LOCK){
	try {
	CHECKSUM_CALC.reset();
	CHECKSUM_CALC.update(jspFilePath.getBytes("utf16")); //$NON-NLS-1$
	persistedTranslatorFileName = Long.toString(CHECKSUM_CALC.getValue()) + ".translator"; //$NON-NLS-1$
	} catch (UnsupportedEncodingException e) {
	Logger.logException("Could not get utf16 encoded bytes to create checksum to store persisted file.", e); //$NON-NLS-1$
	}
	}

	IPath location = PERSIST_LOCATION;

	// ensure the folder exists on disk
	File folder = new File(location.toOSString());
	if (!folder.isDirectory()) {
	try {
	folder.mkdir();
	}
	catch (SecurityException e) {
	}
	}

	location = location.addTrailingSeparator();
	location = location.append(persistedTranslatorFileName);
	return location.toOSString();
	}

	/**
	* <p>Gets the associated {@link JSPTranslator} for a specific JSP file.</p>
	* <p><b>NOTE: </b><i>This does not get the persisted translator but rather the
	* associated translator in memory</i></p>
	*
	* @param jspFile {@link IFile} to the JSP file that the associated {@link JSPTranslator}
	* is needed for
	* @return {@link JSPTranslator} associated with the given <code>jspFilePath</code>, or
	* <code>null</code> if none can be found.
	*/
	private static JSPTranslator getJSPTranslator(IFile jspFile) {
	IStructuredModel model = null;
	JSPTranslator translator = null;
	try {
	model = StructuredModelManager.getModelManager().getModelForRead(jspFile);
	if(model instanceof IDOMModel) {
	IDOMDocument doc = ((IDOMModel)model).getDocument();
	ModelHandlerForJSP.ensureTranslationAdapterFactory(model);
	JSPTranslationAdapter adapter = (JSPTranslationAdapter)doc.getAdapterFor(IJSPTranslation.class);

	//don't want to persist a translator that has not already been requested
	if(adapter != null && adapter.hasTranslation()) {
	translator = adapter.getJSPTranslation().getTranslator();
	}
	}
	} catch (IOException e) {
	Logger.logException("Could not get translator for " + jspFile.getName() + //$NON-NLS-1$
	" because could not read model for same.", e); //$NON-NLS-1$
	} catch (CoreException e) {
	Logger.logException("Could not get translator for " + jspFile.getName() + //$NON-NLS-1$
	" because could not read model for same.", e); //$NON-NLS-1$
	} finally {
	if(model != null) {
	model.releaseFromRead();
	}
	}

	return translator;
	}

	/**
	* <p>Persists a {@link JSPTranslator} to disk for a specific JSP file</p>
	*
	* @param translator {@link JSPTranslator} to persist to disk
	* @param jspFilePath {@link IPath} to the JSP file the given <code>translator</code> is for
	*/
	private static void persistTranslator(JSPTranslator translator, String filePath) {
	try {
	FileOutputStream fos = new FileOutputStream(filePath);
	ObjectOutputStream out = new ObjectOutputStream(fos);
	out.writeObject(translator);
	out.close();
	} catch (IOException e) {
	Logger.logException("Was unable to externalize JSPTranslator " + translator + //$NON-NLS-1$
	" to " + filePath, e); //$NON-NLS-1$
	}
	}

	/**
	* @param path {@link IPath} to the JSP file that the persisted translator is needed for
	* @return The persisted translator {@link File} for the JSP file at the given path
	* or <code>null</code> if no persisted translator exists for the JSP file at the given path
	*/
	private static File getPersistedFile(IPath path) {
	return new File(getPersistedTranslatorFilePath(path.toString()));
	}
	}