MiaoNashorn/src/main/java/pw/yumc/MiaoNashorn/MiaoNashorn.java

104 lines
4.0 KiB
Java

package pw.yumc.MiaoNashorn;
import sun.misc.Unsafe;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import java.io.File;
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.StandardCopyOption;
/**
* 喵式脚本
*
* @author 喵♂呜
* @since 2016年8月29日 上午7:50:39
*/
public class MiaoNashorn {
private static String MavenRepo = "https://maven.aliyun.com/repository/public";
private static final Object ucp;
private static final MethodHandle addURLMethodHandle;
static {
try {
ClassLoader loader = Thread.currentThread().getContextClassLoader();
Field theUnsafe = sun.misc.Unsafe.class.getDeclaredField("theUnsafe");
theUnsafe.setAccessible(true);
Unsafe unsafe = (Unsafe) theUnsafe.get(null);
Field field = MethodHandles.Lookup.class.getDeclaredField("IMPL_LOOKUP");
MethodHandles.Lookup lookup = (MethodHandles.Lookup) unsafe.getObject(unsafe.staticFieldBase(field), unsafe.staticFieldOffset(field));
Field ucpField;
try {
ucpField = loader.getClass().getDeclaredField("ucp");
} catch (NoSuchFieldException e) {
ucpField = loader.getClass().getSuperclass().getDeclaredField("ucp");
}
long offset = unsafe.objectFieldOffset(ucpField);
ucp = unsafe.getObject(loader, offset);
Method method = ucp.getClass().getDeclaredMethod("addURL", URL.class);
addURLMethodHandle = lookup.unreflect(method);
createEngine();
} catch (Throwable e) {
throw new RuntimeException(e);
}
}
public static void log(String format, Object... args) {
System.out.println("[MiaoNashorn] " + String.format(format, args));
}
private static void createEngine() throws Throwable {
String extDirs = System.getProperty("java.ext.dirs");
if (extDirs != null) {
String[] dirs = extDirs.split(File.pathSeparator);
for (String dir : dirs) {
File nashorn = new File(dir, "nashorn.jar");
if (nashorn.exists()) {
loadJar(nashorn);
System.out.println("扩展目录发现 Nashorn 已加载完成!");
}
}
} else {
loadLocalNashorn();
}
}
private static void loadLocalNashorn() throws Throwable {
File libRootFile = new File("plugins/MiaoNashorn", "libs");
libRootFile.mkdirs();
log("从云端加载 Nashorn 请稍候...");
String libRoot = libRootFile.getCanonicalPath();
downloadJar(libRoot, "org.openjdk.nashorn", "nashorn-core", "15.2");
downloadJar(libRoot, "org.ow2.asm", "asm", "9.1");
downloadJar(libRoot, "org.ow2.asm", "asm-commons", "9.1");
downloadJar(libRoot, "org.ow2.asm", "asm-tree", "9.1");
downloadJar(libRoot, "org.ow2.asm", "asm-util", "9.1");
log("云端 Nashorn 已加载完成!");
}
private static void loadJar(File file) throws Throwable {
addURLMethodHandle.invoke(ucp, file.toURI().toURL());
}
private static void downloadJar(String engineRoot, String groupId, String artifactId, String version) throws Throwable {
File lib = new File(engineRoot, artifactId + ".jar");
if (!lib.exists()) {
log("正在下载类库 %s 版本 %s 请稍候...", artifactId, version);
Files.copy(new URL(MavenRepo +
String.format("/%1$s/%2$s/%3$s/%2$s-%3$s.jar",
groupId.replace(".", "/"),
artifactId,
version)
).openStream(),
lib.toPath(),
StandardCopyOption.REPLACE_EXISTING);
}
loadJar(lib);
}
}