org.jacpfx.rcp.util.ClassFinder Maven / Gradle / Ivy
package org.jacpfx.rcp.util;
import java.io.File;
import java.io.IOException;
import java.nio.file.*;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.jar.JarEntry;
import java.util.jar.JarInputStream;
import java.util.stream.Collectors;
import java.util.stream.Stream;
/**
* Created with IntelliJ IDEA.
* User: Andy Moncsek
* Date: 19.07.13
* Time: 10:43
* Find classes for defined packages.
*/
public class ClassFinder {
/**
* Defined classpath
*/
private static final String CLASSPATH = System.getProperty("java.class.path");
private static final String OS = System.getProperty("os.name").toLowerCase();
private static final String CLASS_DOT = ".";
private static final String CLASS_BACKSLASH_DOT = "\\.";
private static final String CLASS_SLASH = "/";
private static final String CLASS_DOLLAR = "$";
private static final String CLASS_FILE = ".class";
private static final String CLASS_PROJECT_SEPERATOR = "classes";
private static final int CLASS_PROJECT_SEPERATOR_LENGTH = 8;
/**
* List with the directories on the classpath (containing .class files)
*/
private final List binDirs;
private final List jarsFiles;
private final PathMatcher matcher =
FileSystems.getDefault().getPathMatcher("glob:*.class");
private static final String FILE_SEPERATOR;
static {
FILE_SEPERATOR = isWindows() ? File.separator + File.separator : File.separator;
}
private static boolean isWindows() {
return (OS.contains("win"));
}
/**
* Default constructur initializes the directories indicated by the
* CLASSPATH, if they are not yet initialized.
*/
public ClassFinder() {
binDirs = initClassPathDir();
jarsFiles = initClassPathJars();
}
/**
* Initialize the directories based on the classpath
*/
private List initClassPathDir() {
final String[] cs = CLASSPATH.split(File.pathSeparator);
final Stream entries = Stream.of(cs);
return entries
.map(s -> FileSystems.getDefault().getPath(s))
.filter(s -> Files.isDirectory(s, LinkOption.NOFOLLOW_LINKS)).collect(Collectors.toList());
}
private List initClassPathJars() {
final String[] cs = CLASSPATH.split(File.pathSeparator);
final Stream entries = Stream.of(cs);
return entries
.map(s -> FileSystems.getDefault().getPath(s))
.filter(s -> Files.isRegularFile(s, LinkOption.NOFOLLOW_LINKS)).collect(Collectors.toList());
}
public List getClasseNamesInPackage
(Path jar, String packageName) {
final List classes = new ArrayList();
packageName = packageName.replaceAll(CLASS_BACKSLASH_DOT, CLASS_SLASH);
try {
final JarInputStream jarFile = new JarInputStream
(Files.newInputStream(jar));
while (true) {
JarEntry jarEntry = jarFile.getNextJarEntry();
if (jarEntry == null) {
break;
}
if ((jarEntry.getName().startsWith(packageName)) &&
(jarEntry.getName().endsWith(CLASS_FILE))) {
classes.add(jarEntry.getName().replaceAll(CLASS_SLASH, CLASS_BACKSLASH_DOT).replace(CLASS_FILE,""));
}
}
} catch (Exception e) {
e.printStackTrace();
}
return classes;
}
/**
* Retrive all classes of the indicated package. The package is searched in
* all classpath directories that are directories
*
* @param packageName name of the package as 'ch.sahits.civ'
* @return Array of found classes
* @throws ClassNotFoundException no class was found in classpath
*/
public Class[] getAll(final String packageName) throws ClassNotFoundException {
final String packageDir = convertPackege(packageName);
final List files = new CopyOnWriteArrayList<>();
final PathMatcher folderMatcher =
FileSystems.getDefault().getPathMatcher("glob:**" + convertPackageToRegex(packageName) + "**");
final SimpleFileVisitor visitor = new CollectingFileVisitor(files, folderMatcher);
binDirs.parallelStream().forEach(dir -> {
try {
Files.walkFileTree(dir, visitor);
} catch (IOException e) {
e.printStackTrace();
}
});
final List result = exctractClasses(packageDir, files);
if(!result.isEmpty())return result.toArray(new Class[result.size()]);
return findClassesInJar(packageName);
}
private Class[] findClassesInJar(final String packageName) {
// scan jar files
final List> res = jarsFiles.
stream().
map(path -> getClasseNamesInPackage(path, packageName)).
collect(Collectors.toList());
final Optional> classes = res.
stream().
reduce((a, b) -> {
a.addAll(b);
return a;
}).
map(this::loadClasses);
if(!classes.isPresent()) return null;
final List resultTmp = classes.get();
return resultTmp.toArray(new Class[resultTmp.size()]);
}
private List loadClasses(List files) {
return files
.stream()
.map(this::loadClass)
.filter(clazz -> clazz != null)
.collect(Collectors.toList());
}
private List exctractClasses(final String packageDir, List files) {
final String seperator = CLASS_PROJECT_SEPERATOR.concat(FILE_SEPERATOR);
return files.parallelStream()
.map(dir -> dir.substring((dir.lastIndexOf(seperator) + CLASS_PROJECT_SEPERATOR_LENGTH), dir.length()))
.filter(classDir -> classDir.contains(packageDir))
.map(subDir -> subDir.replace(File.separator, CLASS_DOT))
.map(className -> className.substring(0, className
.lastIndexOf(CLASS_FILE)))
.filter(classFile -> !classFile.contains(CLASS_DOLLAR))
.map(this::loadClass)
.filter(clazz -> clazz != null)
.collect(Collectors.toList());
}
private Class loadClass(String file) {
try {
return ClassLoader.getSystemClassLoader().loadClass(file);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* Convert the package name into a relative directory path
*
* @param packageName name of the package as 'ch.sahits.civ'
* @return relativ directory to the package
*/
private String convertPackege(String packageName) {
return packageName.replace(CLASS_DOT, File.separator);
}
private String convertPackageToRegex(String packageName) {
return packageName.replace(CLASS_DOT, FILE_SEPERATOR);
}
private class CollectingFileVisitor extends SimpleFileVisitor {
private final List files;
private final PathMatcher folderMatcher;
public CollectingFileVisitor(final List files, final PathMatcher folderMatcher) {
this.files = files;
this.folderMatcher = folderMatcher;
}
@Override
public FileVisitResult preVisitDirectory(Path dir,
BasicFileAttributes attrs) {
return FileVisitResult.CONTINUE;
}
@Override
public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
final boolean matchesFolder = folderMatcher.matches(file);
if (matchesFolder && matcher.matches(file.getFileName())) {
files.add(file.toString());
}
return matchesFolder ? FileVisitResult.CONTINUE : FileVisitResult.SKIP_SUBTREE;
}
@Override
public FileVisitResult visitFileFailed(Path file, IOException e) {
return FileVisitResult.CONTINUE;
}
}
}