nz.ac.waikato.cms.locator.ClassCache Maven / Gradle / Ivy
/*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see
* Use "nz.ac.waikato.cms.locator.ClassCache.LOGLEVEL" with a value of
* "{OFF|SEVERE|WARNING|INFO|CONFIG|FINE|FINER|FINEST}" to set custom
* logging level.
*
* @author fracpete (fracpete at waikato dot ac dot nz)
*/
public class ClassCache
implements Serializable {
/** for serialization. */
private static final long serialVersionUID = -2973185784363491578L;
/**
* For listening to the class traversal and populating the caches.
*
* @author fracpete (fracpete at waikato dot ac dot nz)
*/
public static class Listener
implements TraversalListener {
/** for caching all classes on the class path (package-name <-> Set with classnames). */
protected Map> m_NameCache;
/** caches the classnames per classpath part (path <-> Set with classnames). */
protected Map> m_ClasspathPartCache;
/** the logger in use. */
protected transient Logger m_Logger;
/**
* Initializes the listener.
*/
public Listener() {
m_NameCache = new HashMap<>();
m_ClasspathPartCache = new HashMap<>();
}
/**
* Returns the logger in use.
*
* @return the logger
*/
public synchronized Logger getLogger() {
if (m_Logger == null) {
m_Logger = Logger.getLogger(getClass().getName());
m_Logger.setLevel(LoggingHelper.getLevel(getClass()));
}
return m_Logger;
}
/**
* Gets called when a class is being traversed.
*
* @param classname the current classname
* @param classPathPart the current classpath part this classname is
* located in
*/
@Override
public void traversing(String classname, URL classPathPart) {
String pkgname;
// classname and package
pkgname = ClassPathTraversal.extractPackage(classname);
// add to package cache
if (!m_NameCache.containsKey(pkgname))
m_NameCache.put(pkgname, new HashSet<>());
m_NameCache.get(pkgname).add(classname);
// add to classpath part cache
if (!m_ClasspathPartCache.containsKey(classPathPart))
m_ClasspathPartCache.put(classPathPart, new HashSet<>());
m_ClasspathPartCache.get(classPathPart).add(classname);
}
/**
* Returns the name cache.
*
* @return the cache
*/
public Map> getNameCache() {
return m_NameCache;
}
/**
* Returns the classpath path cache.
*
* @return the cache
*/
public Map> getClasspathPartCache() {
return m_ClasspathPartCache;
}
}
/** the logger in use. */
protected transient Logger m_Logger;
/** for caching all classes on the class path (package-name <-> Set with classnames). */
protected Map> m_NameCache;
/** the classpath path part cache (classpath part <-> set with classnames). */
protected Map> m_ClasspathPartCache;
/**
* Initializes the cache.
* Uses the {@link ClassPathTraversal} class.
*/
public ClassCache() {
super();
initialize(new ClassPathTraversal());
}
/**
* Initializes the cache.
*
* @param traversal the traversal instance to use, can be null
*/
public ClassCache(ClassTraversal traversal) {
super();
initialize((traversal == null) ? new ClassPathTraversal() : traversal);
}
/**
* Returns whether logging is enabled.
*
* @return true if enabled
*/
public boolean isLoggingEnabled() {
return true;
}
/**
* Returns the logger in use.
*
* @return the logger
*/
public synchronized Logger getLogger() {
if (m_Logger == null) {
m_Logger = Logger.getLogger(getClass().getName());
m_Logger.setLevel(LoggingHelper.getLevel(getClass()));
}
return m_Logger;
}
/**
* Removes the classname from the cache.
*
* @param classname the classname to remove
* @return true if the removal changed the cache
*/
public boolean remove(String classname) {
String pkgname;
Set names;
for (URL part: m_ClasspathPartCache.keySet())
m_ClasspathPartCache.get(part).remove(classname);
classname = ClassPathTraversal.cleanUp(classname);
pkgname = ClassPathTraversal.extractPackage(classname);
names = m_NameCache.get(pkgname);
if (names != null)
return names.remove(classname);
else
return false;
}
/**
* Returns all the stored packages.
*
* @return the package names
*/
public Iterator packages() {
return m_NameCache.keySet().iterator();
}
/**
* Returns all the stored packages that match the provided regular expression.
*
* @param regexp the regular expression that the package names must match
* @return the package names
*/
public Iterator packages(String regexp) {
List result;
Pattern pattern;
result = new ArrayList<>();
pattern = Pattern.compile(regexp);
for (String pkg: m_NameCache.keySet()) {
if (pattern.matcher(pkg).matches())
result.add(pkg);
}
return result.iterator();
}
/**
* Returns all the classes for the given package.
*
* @param pkgname the package to get the classes for
* @return the classes
*/
public Set getClassnames(String pkgname) {
if (m_NameCache.containsKey(pkgname))
return m_NameCache.get(pkgname);
else
return new HashSet<>();
}
/**
* Returns all the stored classpath parts.
*
* @return the classpath parts
*/
public Iterator classpathParts() {
return m_ClasspathPartCache.keySet().iterator();
}
/**
* Returns all the stored classpath parts that match the provided regular expression.
*
* @param regexp the regular expression that the URLs must match
* @return the classpath parts
*/
public Iterator classpathParts(String regexp) {
List result;
Pattern pattern;
result = new ArrayList<>();
pattern = Pattern.compile(regexp);
for (URL part : m_ClasspathPartCache.keySet()) {
if (pattern.matcher(part.toExternalForm()).matches())
result.add(part);
}
return result.iterator();
}
/**
* Returns all the classes for the given classpath part.
*
* @param part the classpath part to get the classes for
* @return the classes
*/
public Set getClassnames(URL part) {
if (m_ClasspathPartCache.containsKey(part))
return m_ClasspathPartCache.get(part);
else
return new HashSet<>();
}
/**
* Initializes the cache.
*/
protected void initialize(ClassTraversal traversal) {
Listener listener;
listener = new Listener();
traversal.traverse(listener);
m_NameCache = listener.getNameCache();
m_ClasspathPartCache = listener.getClasspathPartCache();
}
/**
* Returns whether the cache is empty.
*
* @return true if empty
*/
public boolean isEmpty() {
return (m_NameCache == null) || m_NameCache.isEmpty();
}
/**
* For testing only.
*
* @param args ignored
*/
public static void main(String[] args) {
ClassCache cache = new ClassCache();
// packages
System.out.println("--> Packages");
Iterator pkgs = cache.packages();
List pkgsSorted = new ArrayList<>();
while (pkgs.hasNext())
pkgsSorted.add(pkgs.next());
Collections.sort(pkgsSorted);
for (String pkg : pkgsSorted)
System.out.println(pkg + ": " + cache.getClassnames(pkg).size());
// packages (nz.*)
System.out.println("--> Packages (nz.*)");
pkgs = cache.packages("nz.*");
pkgsSorted = new ArrayList<>();
while (pkgs.hasNext())
pkgsSorted.add(pkgs.next());
Collections.sort(pkgsSorted);
for (String pkg : pkgsSorted)
System.out.println(pkg + ": " + cache.getClassnames(pkg).size());
// packages
System.out.println("--> Classpath parts");
Iterator parts = cache.classpathParts();
List partsSorted = new ArrayList<>();
while (parts.hasNext())
partsSorted.add(parts.next());
Collections.sort(partsSorted, new Comparator() {
@Override
public int compare(URL o1, URL o2) {
return o1.toExternalForm().compareTo(o2.toExternalForm());
}
});
for (URL part : partsSorted)
System.out.println(part + ": " + cache.getClassnames(part).size());
// packages (.*classes.*)
System.out.println("--> Classpath parts (.*classes.*)");
parts = cache.classpathParts(".*classes.*");
partsSorted = new ArrayList<>();
while (parts.hasNext())
partsSorted.add(parts.next());
Collections.sort(partsSorted, new Comparator() {
@Override
public int compare(URL o1, URL o2) {
return o1.toExternalForm().compareTo(o2.toExternalForm());
}
});
for (URL part : partsSorted)
System.out.println(part + ": " + cache.getClassnames(part).size());
}
}