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Units of tool for class and class loading. Also with some tool type.
The newest version!
/*
* Source of units
* Copyright (C) 2023. Zen.Liu
*
* SPDX-License-Identifier: GPL-2.0-only WITH Classpath-exception-2.0"
*
* 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; version 2.
* 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, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Class Path Exception
* Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination.
* As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.
*/
package cn.zenliu.classes;
import lombok.SneakyThrows;
import org.jetbrains.annotations.ApiStatus;
import org.jetbrains.annotations.Nullable;
import java.io.IOException;
import java.nio.file.FileVisitOption;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.*;
import java.util.function.Function;
import java.util.jar.JarFile;
/**
* @author Zen.Liu
* @since 2023-05-07
*/
@SuppressWarnings("unused")
public interface Classes {
@SuppressWarnings("unchecked")
@SneakyThrows
@ApiStatus.AvailableSince("0.1.5")
static Class forName(String name, ClassLoader cl) {
return (Class) (cl == null ? Thread.currentThread().getContextClassLoader() : cl).loadClass(name);
}
@SuppressWarnings("unchecked")
@SneakyThrows
static T load(Class type, String suffix, ClassLoader cl) {
return (T) (cl == null ? type.getClassLoader() : cl).loadClass(type.getName() + suffix).getConstructor().newInstance();
}
/**
* this method just do an unchecked directly cast.
*
* @param src source list
* @param parent type
* @param current type
* @return unsafe casted list
*/
@SuppressWarnings("unchecked")
static List upcast(List src) {
return ((List) src);
}
/**
* @see #upcast(List)
*/
@SuppressWarnings("unchecked")
static Set upcast(Set src) {
return ((Set) src);
}
/**
* @see #upcast(List)
*/
@SuppressWarnings("unchecked")
static Collection upcast(Collection src) {
return ((Collection) src);
}
/**
* Create set form a Collection use {@link DelegateSet}
*
* @param src source collection
* @param element type
*/
static Set set(Collection src) {
return src == null ? null : DelegateSet.of(src, false);
}
/**
* Create set from a Collection use {@link DelegateTransformerSet}
*
* @param src source collection
* @param element type
* @param source element type
* @param convTo convert from source type to element type
* @param convFrom convert from element type to source type
*/
static Set set(Collection src, Function convTo, Function convFrom) {
return src == null ? null :DelegateTransformerSet.of(src, convFrom, convTo, false);
}
/**
* checked cast.
*
* @param type type to cast to
* @param i instance
* @return empty if it can't cast to T
*/
@SuppressWarnings("unchecked")
static Optional cast(Class type, Object i) {
if (type.isInstance(i)) return Optional.of((T) i);
return Optional.empty();
}
static boolean classExists(String name, @Nullable ClassLoader loader) {
loader = loader == null ? Thread.currentThread().getContextClassLoader() : loader;
try {
loader.loadClass(name);
return true;
} catch (ClassNotFoundException e) {
return false;
}
}
/**
* load a MapStruct mapper.
*/
static T mapper(Class cls) {
return load(cls, "Impl");
}
/**
* load a implement of cls with suffix.
*/
@SuppressWarnings("unchecked")
@SneakyThrows
static T load(Class cls, String suffix) {
return (T) cls.getClassLoader().loadClass(cls.getName() + suffix).getConstructor().newInstance();
}
@SuppressWarnings("unchecked")
@SneakyThrows
static T loadClass(Class cls, String clsName) {
return (T) cls.getClassLoader().loadClass(clsName).getConstructor().newInstance();
}
@SneakyThrows
static Class forName(String clsName) {
return Classes.class.getClassLoader().loadClass(clsName);
}
String POM_VERSION_UNKNOWN = "unknown";
/**
* fetch jar version from pom.properties, only effect with Maven compact jar.
* @param type type class in a Jar
* @return POM_VERSION_UNKNOWN if failed
*/
@SuppressWarnings("resource")
@SneakyThrows
static String pomVersion(Class type) {
try {
var file = type.getProtectionDomain().getCodeSource().getLocation().getFile();
if (file.endsWith("jar")) {
try (var jar = new JarFile(file)) {
var it = jar.entries();
while (it.hasMoreElements()) {
var e = it.nextElement();
if (e.getName().endsWith("pom.properties")) {
var prop = new Properties();
prop.load(type.getClassLoader().getResourceAsStream(e.getName()));
return prop.getProperty("version");
}
}
}
} else { //from path
var prop = Files.find(Paths.get(file.indexOf('/') == 0 && file.indexOf(':') > 0 ? file.substring(1) : file),
20,
(p, a) -> a.isRegularFile() && p.endsWith("pom.properties"), FileVisitOption.FOLLOW_LINKS)
.findFirst();
if (prop.isPresent()) {
var p = new Properties();
p.load(prop.get().toUri().toURL().openStream());
return p.getProperty("version");
}
}
return POM_VERSION_UNKNOWN;
} catch (IOException e) {
return POM_VERSION_UNKNOWN;
}
}
}