Java tutorial
/******************************************************************************* * Copyright (c) 2009 Red Hat, Inc. * Distributed under license by Red Hat, Inc. All rights reserved. * This program is 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: * Red Hat, Inc. - initial API and implementation ******************************************************************************/ package org.jboss.tools.common.model.filesystems.impl; import java.io.File; import java.io.IOException; import java.util.ArrayList; import java.util.HashMap; import java.util.HashSet; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Set; import org.eclipse.core.resources.IProject; import org.eclipse.core.resources.ResourcesPlugin; import org.eclipse.core.runtime.CoreException; import org.eclipse.core.runtime.IPath; import org.eclipse.core.runtime.Path; import org.eclipse.jdt.core.ElementChangedEvent; import org.eclipse.jdt.core.IClasspathEntry; import org.eclipse.jdt.core.IElementChangedListener; import org.eclipse.jdt.core.IJavaElementDelta; import org.eclipse.jdt.core.IJavaProject; import org.eclipse.jdt.core.JavaCore; import org.eclipse.jdt.core.JavaModelException; import org.jboss.tools.common.model.XModelObject; import org.jboss.tools.common.model.XModelObjectConstants; import org.jboss.tools.common.model.plugin.ModelPlugin; import org.jboss.tools.common.model.util.EclipseResourceUtil; import org.jboss.tools.common.model.util.XModelObjectUtil; import org.jboss.tools.common.util.UniquePaths; /** * * @author Viacheslav Kabanovich * */ public class Libs implements IElementChangedListener { protected FileSystemsImpl object; protected List<String> paths = null; Map<IPath, String> paths2 = new HashMap<IPath, String>(); Set<String> projects = new HashSet<String>(); LibraryNames libraryNames = new LibraryNames(); int excudedState = 0; List<LibsListener> listeners = new ArrayList<LibsListener>(); public Libs(FileSystemsImpl object) { this.object = object; } public void init() { JavaCore.addElementChangedListener(this); } public void destroy() { JavaCore.removeElementChangedListener(this); } private IProject getProjectResource() { return EclipseResourceUtil.getProject(object); } /** * Path should use the separator provided by the current OS. * For example IPath.toOSString() or java.io.File.getCanonicalPath(). * * @param path * @return */ public XModelObject getLibrary(String path) { String libName = libraryNames.getName(path); if (libName == null) { //compatibility to old code. libName = LIB_PREFIX + new File(path).getName(); } return object.getChildByPath(libName); } public XModelObject getLibrary(File f) { XModelObject result = null; if (f.exists()) { String path = ""; try { path = f.getCanonicalPath(); } catch (IOException e) { path = f.getAbsolutePath().replace('\\', '/'); } result = getLibrary(path); } return result; } public boolean update() { boolean result = false; int cpv = classpathVersion; if (hasToUpdatePaths()) { result = updatePaths(getNewPaths(), cpv); if (isExcludedStateChanged()) { result = true; } if (paths == null && result) { fire(); return true; } } if (paths != null && fsVersion < pathsVersion) { updateFileSystems(paths, 0); } fsVersion = pathsVersion; if (result) { fire(); } return result; } public void requestForUpdate() { classpathVersion++; } synchronized boolean hasToUpdatePaths() { return (classpathVersion > pathsVersion); } private List<String> getNewPaths() { List<String> result = null; try { result = EclipseResourceUtil.getAllVisibleLibraries(getProjectResource()); List<String> jre = EclipseResourceUtil.getJREClassPath(getProjectResource()); if (jre != null) result.removeAll(jre); if (result != null) { Iterator<String> it = result.iterator(); while (it.hasNext()) { String path = it.next(); String fileName = new File(path).getName(); if (EclipseResourceUtil.isJar(path) && EclipseResourceUtil.SYSTEM_JAR_SET.contains(fileName)) { it.remove(); } } } updateProjects(); } catch (CoreException e) { ModelPlugin.getDefault().logError(e); } return result; } private void updateProjects() throws JavaModelException { Set<String> result = new HashSet<String>(); IJavaProject javaProject = EclipseResourceUtil.getJavaProject(getProjectResource()); if (javaProject != null) { result.add(getProjectResource().getName()); IClasspathEntry[] es = javaProject.getResolvedClasspath(true); for (int i = 0; i < es.length; i++) { if (es[i].getEntryKind() == IClasspathEntry.CPE_PROJECT) { IProject p = ResourcesPlugin.getWorkspace().getRoot().getProject(es[i].getPath().lastSegment()); if (p == null || !p.isAccessible()) continue; result.add(p.getName()); } } } projects = result; } private boolean isExcludedStateChanged() { try { int es = computeExcludedState(); if (es != excudedState) { excudedState = es; return true; } } catch (JavaModelException e) { ModelPlugin.getDefault().logError(e); } return false; } private int computeExcludedState() throws JavaModelException { int result = 0; IJavaProject javaProject = EclipseResourceUtil.getJavaProject(getProjectResource()); if (javaProject != null) { IClasspathEntry[] es = javaProject.getResolvedClasspath(true); for (int i = 0; i < es.length; i++) { IPath p = es[i].getPath(); IPath[] ps = es[i].getExclusionPatterns(); if (ps != null && ps.length > 0) { for (int j = 0; j < ps.length; j++) { String key = p.toString() + "/" + ps[j].toString(); //$NON-NLS-1$ result += key.hashCode(); } } } } return result; } private synchronized boolean updatePaths(List<String> newPaths, int cpv) { if (cpv <= pathsVersion) { return false; } pathsVersion = cpv; if (paths == null && newPaths == null) return false; if ((newPaths != null && paths != null) && (paths.size() == newPaths.size())) { boolean b = false; for (int i = 0; i < paths.size() && !b; i++) { if (!paths.get(i).equals(newPaths.get(i))) b = true; } if (!b) return false; } paths = newPaths; createMap(); return true; } public static String LIB_PREFIX = "lib-"; //$NON-NLS-1$ /** * This method is designed to run safe when invoked by several concurrent threads. * Each thread requesting file systems needs them up-to-date when this method returns. * If thread 1 is already running update, and thread 2 is going to request file systems, * it has to start this method independently, because it cannot rely on the other thread * completing before the file systems are obtained. * Synchronizing this method would involve high risk of a deadlock, * concurrent modification is a better solution if implemented safely. * * @param paths * @param iteration */ private void updateFileSystems(List<String> paths, int iteration) { Set<String> oldPaths = libraryNames.getPaths(); for (String p : oldPaths) { if (!paths.contains(p)) { String n = libraryNames.getName(p); if (n != null) { XModelObject o = object.getChildByPath(n); if (o != null) { o.removeFromParent(); } } libraryNames.removePath(p); } } XModelObject[] fs = object.getChildren(); Set<XModelObject> fss = new HashSet<XModelObject>(); for (int i = 0; i < fs.length; i++) { if (fs[i].getAttributeValue(XModelObjectConstants.ATTR_NAME).startsWith(LIB_PREFIX)) { fss.add(fs[i]); } } if (paths != null) for (int i = 0; i < paths.size(); i++) { String path = paths.get(i); boolean isJar = EclipseResourceUtil.isJar(path); String libEntity = isJar ? "FileSystemJar" : "FileSystemFolder"; //$NON-NLS-1$ //$NON-NLS-2$ String fileName = new File(path).getName(); String jsname = libraryNames.getExistingOrNewName(path, fileName); XModelObject o = object.getChildByPath(jsname); if (o != null) { fss.remove(o); if (o instanceof JarSystemImpl) { ((JarSystemImpl) o).update(); } } else { o = object.getModel().createModelObject(libEntity, null); o.setAttributeValue(XModelObjectConstants.ATTR_NAME, jsname); o.setAttributeValue(XModelObjectConstants.ATTR_NAME_LOCATION, path); o.set(FileSystemsLoader.IS_ADDED_TO_CLASSPATH, XModelObjectConstants.TRUE); object.addChild(o); // object.setModified(true); } libraryNames.put(path, jsname); } for (XModelObject o : fss) { String path = XModelObjectUtil.expand(o.getAttributeValue(XModelObjectConstants.ATTR_NAME_LOCATION), o.getModel(), null); if (XModelObjectConstants.TRUE.equals(o.get(FileSystemsLoader.IS_ADDED_TO_CLASSPATH))) { o.removeFromParent(); } else if (!new File(path).exists()) { o.removeFromParent(); } } List<String> newPaths = this.paths; if (newPaths != null && (paths != newPaths || !libraryNames.isValidList(newPaths))) { if (iteration == 5) { ModelPlugin.getDefault().logWarning("Iterative update of file systems for project " //$NON-NLS-1$ + EclipseResourceUtil.getProject(object) + " is interrupted to prevent deadlock."); //$NON-NLS-1$ } else { updateFileSystems(newPaths, iteration + 1); } } } public List<String> getPaths() { return paths; } public Map<IPath, String> getPathsAsMap() { return paths2; } private void createMap() { paths2.clear(); if (paths != null) { for (String p : paths) { paths2.put(UniquePaths.getInstance().intern(new Path(p)), p); } } } public synchronized void addListener(LibsListener listener) { listeners.add(listener); } public synchronized void removeListener(LibsListener listener) { listeners.remove(listener); } void fire() { for (LibsListener listener : getListeners()) { listener.pathsChanged(paths); } } private synchronized LibsListener[] getListeners() { return listeners.toArray(new LibsListener[0]); } int classpathVersion = 0; int pathsVersion = -1; int fsVersion = -1; public void elementChanged(ElementChangedEvent event) { IProject project = getProjectResource(); if (project == null || !project.exists()) { JavaCore.removeElementChangedListener(this); return; } for (IJavaElementDelta dc : event.getDelta().getAffectedChildren()) { if (dc.getElement() instanceof IJavaProject && (isReleventProject(((IJavaProject) dc.getElement()).getProject()))) { int f = dc.getFlags(); if ((f & (IJavaElementDelta.F_CLASSPATH_CHANGED | IJavaElementDelta.F_RESOLVED_CLASSPATH_CHANGED)) != 0) { requestForUpdate(); return; } else { for (IJavaElementDelta d1 : dc.getAffectedChildren()) { // IJavaElement e = d1.getElement(); if (d1.getKind() == IJavaElementDelta.ADDED || d1.getKind() == IJavaElementDelta.REMOVED) { requestForUpdate(); return; } } } } } } private boolean isReleventProject(IProject p) { return projects.contains(p.getName()); } public void libraryChanged(JarSystemImpl jar) { for (LibsListener listener : getListeners()) { listener.libraryChanged(jar.getLocation()); } } } class LibraryNames { private Map<String, String> pathToName = new HashMap<String, String>(); private Map<String, String> nameToPath = new HashMap<String, String>(); public synchronized void put(String path, String name) { pathToName.put(path, name); nameToPath.put(name, path); } public synchronized void removePath(String path) { String name = pathToName.remove(path); if (name != null) { nameToPath.remove(name); } } public String getName(String path) { return pathToName.get(path); } public synchronized String getExistingOrNewName(String path, String fileName) { String jsname = getName(path); if (jsname == null) { jsname = Libs.LIB_PREFIX + fileName; int q = 0; while (hasName(jsname)) { jsname = Libs.LIB_PREFIX + fileName + "-" + (++q); //$NON-NLS-1$ } } return jsname; } public String getPath(String name) { return nameToPath.get(name); } public boolean hasName(String name) { return nameToPath.containsKey(name); } public synchronized Set<String> getPaths() { return new HashSet<String>(pathToName.keySet()); } public synchronized boolean isValidList(List<String> paths) { if (pathToName.size() != paths.size()) { return false; } for (String p : paths) { if (!pathToName.containsKey(p)) { return false; } } return true; } }