host.anzo.commons.versioning.Locator Maven / Gradle / Ivy
package host.anzo.commons.versioning;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.text.CharacterIterator;
import java.text.StringCharacterIterator;
import java.util.Locale;
/**
* The Locator is a utility class which is used to find certain items in the
* environment.
*
* @since Ant 1.6
*/
public final class Locator {
/**
* Not instantiable
*/
private Locator() {
}
/**
* Find the directory or jar file the class has been loaded from.
*
* @param c the class whose location is required.
* @return the file or jar with the class or null if we cannot determine the
* location.
* @since Ant 1.6
*/
public static File getClassSource(@NotNull Class c) {
String classResource = c.getName().replace('.', '/') + ".class";
return getResourceSource(c.getClassLoader(), classResource);
}
/**
* Find the directory or jar a given resource has been loaded from.
*
* @param c the classloader to be consulted for the source.
* @param resource the resource whose location is required.
* @return the file with the resource source or null if we cannot determine
* the location.
* @since Ant 1.6
*/
public static @Nullable File getResourceSource(ClassLoader c, String resource) {
if (c == null)
c = Locator.class.getClassLoader();
URL url;
if (c == null)
url = ClassLoader.getSystemResource(resource);
else
url = c.getResource(resource);
if (url != null) {
String u = url.toString();
if (u.startsWith("jar:file:")) {
int pling = u.indexOf("!");
String jarName = u.substring(4, pling);
return new File(fromURI(jarName));
} else if (u.startsWith("file:")) {
int tail = u.indexOf(resource);
String dirName = u.substring(0, tail);
return new File(fromURI(dirName));
}
}
return null;
}
/**
* Constructs a file path from a file: URI.
*
*
* Will be an absolute path if the given URI is absolute.
*
*
*
* Swallows '%' that are not followed by two characters, doesn't deal with
* non-ASCII characters.
*
*
* @param uri the URI designating a file in the local filesystem.
* @return the local file system path for the file.
* @since Ant 1.6
*/
public static @NotNull String fromURI(String uri) {
URL url = null;
try {
url = new URL(uri);
} catch (MalformedURLException emYouEarlEx) {
// Ignore malformed exception
}
if (url == null || !"file".equals(url.getProtocol())) {
throw new IllegalArgumentException("Can only handle valid file: URIs");
}
StringBuilder buf = new StringBuilder(url.getHost());
if (!buf.isEmpty()) {
buf.insert(0, File.separatorChar).insert(0, File.separatorChar);
}
String file = url.getFile();
int queryPos = file.indexOf('?');
buf.append(queryPos < 0 ? file : file.substring(0, queryPos));
uri = buf.toString().replace('/', File.separatorChar);
if (File.pathSeparatorChar == ';' && uri.startsWith("\\") && uri.length() > 2 && Character.isLetter(uri.charAt(1)) && uri.lastIndexOf(':') > -1)
uri = uri.substring(1);
return decodeUri(uri);
}
/**
* Decodes an Uri with % characters.
*
* @param uri String with the uri possibly containing % characters.
* @return The decoded Uri
*/
private static @NotNull String decodeUri(@NotNull String uri) {
if (uri.indexOf('%') == -1)
return uri;
StringBuilder sb = new StringBuilder();
CharacterIterator iter = new StringCharacterIterator(uri);
for (char c = iter.first(); c != CharacterIterator.DONE; c = iter.next())
if (c == '%') {
char c1 = iter.next();
if (c1 != CharacterIterator.DONE) {
int i1 = Character.digit(c1, 16);
char c2 = iter.next();
if (c2 != CharacterIterator.DONE) {
int i2 = Character.digit(c2, 16);
sb.append((char) ((i1 << 4) + i2));
}
}
} else
sb.append(c);
return sb.toString();
}
/**
* Get the File necessary to load the Sun compiler tools. If the classes are
* available to this class, then no additional URL is required and null is
* returned. This may be because the classes are explicitly in the class
* path or provided by the JVM directly.
*
* @return the tools jar as a File if required, null otherwise.
*/
public static @Nullable File getToolsJar() {
// firstly check if the tools jar is already in the classpath
boolean toolsJarAvailable = false;
try {
// just check whether this throws an exception
Class.forName("com.sun.tools.javac.Main");
toolsJarAvailable = true;
} catch (Exception e) {
try {
Class.forName("sun.tools.javac.Main");
toolsJarAvailable = true;
} catch (Exception e2) {
// ignore
}
}
if (toolsJarAvailable)
return null;
// couldn't find compiler - try to find tools.jar
// based on java.home setting
String javaHome = System.getProperty("java.home");
if (javaHome.toLowerCase(Locale.US).endsWith("jre"))
javaHome = javaHome.substring(0, javaHome.length() - 4);
File toolsJar = new File(javaHome + "/lib/tools.jar");
if (!toolsJar.exists()) {
System.out.println("Unable to locate tools.jar. " + "Expected to find it in " + toolsJar.getPath());
return null;
}
return toolsJar;
}
/**
* Get an array of URLs representing all of the jar files in the given
* location. If the location is a file, it is returned as the only element
* of the array. If the location is a directory, it is scanned for jar
* files.
*
* @param location the location to scan for Jars.
* @return an array of URLs for all jars in the given location.
* @throws MalformedURLException if the URLs for the jars cannot be formed.
*/
public static URL @NotNull [] getLocationURLs(File location) throws MalformedURLException {
return getLocationURLs(location, new String[]{".jar"});
}
/**
* Get an array of URLs representing all of the files of a given set of
* extensions in the given location. If the location is a file, it is
* returned as the only element of the array. If the location is a
* directory, it is scanned for matching files.
*
* @param location the location to scan for files.
* @param extensions an array of extension that are to match in the directory
* search.
* @return an array of URLs of matching files.
* @throws MalformedURLException if the URLs for the files cannot be formed.
*/
public static URL @NotNull [] getLocationURLs(@NotNull File location, final String[] extensions) throws MalformedURLException {
URL[] urls = new URL[0];
if (!location.exists())
return urls;
if (!location.isDirectory()) {
urls = new URL[1];
String path = location.getPath();
for (String extension : extensions)
if (path.toLowerCase().endsWith(extension)) {
urls[0] = location.toURI().toURL();
break;
}
return urls;
}
File[] matches = location.listFiles((dir, name) -> {
for (String extension : extensions)
if (name.toLowerCase().endsWith(extension))
return true;
return false;
});
urls = new URL[matches.length];
for (int i = 0; i < matches.length; ++i)
urls[i] = matches[i].toURI().toURL();
return urls;
}
}