Java tutorial
/* * This file is part of SpongeClean, licensed under the MIT License (MIT). * * Copyright (c) The VoxelBox <http://thevoxelbox.com> * Copyright (c) contributors * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package org.spongepowered.clean.plugin; import static org.spongepowered.api.plugin.Plugin.ID_PATTERN; import org.apache.logging.log4j.Logger; import org.objectweb.asm.ClassReader; import org.objectweb.asm.tree.AnnotationNode; import org.objectweb.asm.tree.ClassNode; import org.objectweb.asm.tree.TypeAnnotationNode; import org.spongepowered.clean.SGame; import org.spongepowered.plugin.meta.McModInfo; import org.spongepowered.plugin.meta.PluginMetadata; import java.io.BufferedInputStream; import java.io.IOException; import java.io.InputStream; import java.net.URI; import java.net.URISyntaxException; import java.net.URL; import java.net.URLClassLoader; import java.nio.file.DirectoryStream; import java.nio.file.FileVisitOption; import java.nio.file.FileVisitResult; import java.nio.file.FileVisitor; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.PathMatcher; import java.nio.file.Paths; import java.nio.file.SimpleFileVisitor; import java.nio.file.attribute.BasicFileAttributes; import java.util.ArrayList; import java.util.Collections; import java.util.HashMap; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Set; import java.util.jar.JarFile; import java.util.jar.JarInputStream; import java.util.jar.Manifest; import java.util.zip.ZipEntry; import javax.annotation.Nullable; public class PluginScanner { private static final String ID_WARNING = "Plugin IDs should be lowercase, and only contain characters from " + "a-z, dashes or underscores, start with a lowercase letter, and not exceed 64 characters."; private static final String CLASS_EXTENSION = ".class"; private static final String JAR_EXTENSION = ".jar"; private static final PathMatcher CLASS_FILE = path -> path.toString().endsWith(CLASS_EXTENSION); private static final PathMatcher JAR_FILE = path -> path.toString().endsWith(JAR_EXTENSION); private static final DirectoryStream.Filter<Path> JAR_FILTER = path -> path.toString().endsWith(JAR_EXTENSION); private static final String METADATA_FILE = McModInfo.STANDARD_FILENAME; private static final String JAVA_HOME = System.getProperty("java.home"); private static final Logger logger = SGame.getLogger(); @Nullable private FileVisitor<Path> classFileVisitor; public void scanClassPath(URLClassLoader loader, boolean scanJars) { Set<URI> sources = new HashSet<>(); for (URL url : loader.getURLs()) { if (!url.getProtocol().equals("file")) { logger.warn("Skipping unsupported classpath source: {}", url); continue; } if (url.getPath().startsWith(JAVA_HOME)) { logger.trace("Skipping JRE classpath entry: {}", url); continue; } if (!scanJars && url.getFile().endsWith(JAR_EXTENSION)) { logger.trace("Skipping classpath JAR file: {}", url); continue; } URI source; try { source = url.toURI(); } catch (URISyntaxException e) { logger.error("Failed to search for classpath plugins in {}", url); continue; } if (sources.add(source)) { Path path = Paths.get(source); if (Files.isDirectory(path)) { scanClasspathDirectory(path); } else if (scanJars && JAR_FILE.matches(path) && Files.exists(path)) { scanJar(path, true); } } } } private void scanClasspathDirectory(Path dir) { logger.trace("Scanning {} for plugins", dir); if (this.classFileVisitor == null) { this.classFileVisitor = new ClassFileVisitor(); } try { Files.walkFileTree(dir, Collections.singleton(FileVisitOption.FOLLOW_LINKS), Integer.MAX_VALUE, this.classFileVisitor); } catch (IOException e) { logger.error("Failed to search for plugins in {}", dir, e); } } void visitClasspathFile(Path path) { if (CLASS_FILE.matches(path)) { try (InputStream in = Files.newInputStream(path)) { PluginCandidate candidate = scanClassFile(in); if (candidate != null) { SGame.game.pluginManager.addCandidate(candidate); } } catch (IOException e) { logger.error("Failed to search for plugins in {}", path, e); } } } private final class ClassFileVisitor extends SimpleFileVisitor<Path> { @Override public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) { visitClasspathFile(file); return FileVisitResult.CONTINUE; } } void scanDirectory(Path path) { try (DirectoryStream<Path> dir = Files.newDirectoryStream(path, JAR_FILTER)) { for (Path jar : dir) { scanJar(jar, false); } } catch (IOException e) { logger.error("Failed to search for plugins in {}", path, e); } } void scanJar(Path path, boolean classpath) { logger.trace("Scanning {} for plugins", path); List<PluginCandidate> candidates = new ArrayList<>(); List<PluginMetadata> metadata = null; // Open the zip file so we can scan it for plugins try (JarInputStream jar = new JarInputStream(new BufferedInputStream(Files.newInputStream(path)))) { ZipEntry entry = jar.getNextEntry(); if (entry == null) { return; } Manifest manifest = jar.getManifest(); if (manifest == null) { // JarInputStream seems to be only able to find the manifest if // it's one of the first entries... // Try harder to find it anyway - Wtf Java? try (JarFile jarFile = new JarFile(path.toFile())) { manifest = jarFile.getManifest(); } } do { if (entry.isDirectory()) { continue; } final String name = entry.getName(); if (!name.endsWith(CLASS_EXTENSION)) { if (name.equals(METADATA_FILE)) { try { metadata = McModInfo.DEFAULT.read(jar); } catch (IOException e) { logger.error("Failed to read plugin metadata from " + METADATA_FILE + " in {}", path, e); return; } } continue; } PluginCandidate candidate = scanClassFile(jar); if (candidate != null) { candidates.add(candidate); } } while ((entry = jar.getNextEntry()) != null); } catch (IOException e) { logger.error("Failed to scan plugin JAR: {}", path, e); return; } if (!candidates.isEmpty()) { boolean success = false; for (PluginCandidate candidate : candidates) { SGame.game.pluginManager.addCandidate(candidate); // Find matching plugin metadata if (metadata != null) { boolean found = false; for (PluginMetadata meta : metadata) { if (candidate.getId().equals(meta.getId())) { found = true; candidate.setMetadata(meta); break; } } if (!found) { logger.warn("No matching metadata found for plugin '{}' in " + METADATA_FILE + " from {}", candidate.getId(), path); } } } if (success) { if (metadata == null) { logger.warn("{} is missing a valid " + METADATA_FILE + " file." + "This is not a problem when testing plugins, however it is recommended to include one in public plugins.\n" + "Please see https://docs.spongepowered.org/master/en/plugin/plugin-meta.html for details.", path); } } } else if (!classpath) { logger.error( "No valid plugins found in {}. Is the file actually a plugin JAR? Please keep in mind Forge mods can be only loaded on " + "SpongeForge servers, SpongeVanilla supports only Sponge plugins.", path); } } @SuppressWarnings("unchecked") private PluginCandidate scanClassFile(InputStream in) throws IOException { ClassReader reader = new ClassReader(in); ClassNode cn = new ClassNode(); reader.accept(cn, ClassReader.SKIP_CODE | ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES); AnnotationNode plugin = null; boolean isAsync = false; if (cn.visibleTypeAnnotations != null) { for (TypeAnnotationNode an : (List<TypeAnnotationNode>) cn.visibleTypeAnnotations) { if ("Lorg/spongepowered/api/plugin/Plugin;".equals(an.desc)) { plugin = an; } else if ("Lorg/spongepowered/api/plugin/AsyncPlugin;".equals(an.desc)) { isAsync = true; } } } if (cn.visibleAnnotations != null) { for (AnnotationNode an : (List<AnnotationNode>) cn.visibleAnnotations) { if ("Lorg/spongepowered/api/plugin/Plugin;".equals(an.desc)) { plugin = an; } else if ("Lorg/spongepowered/api/plugin/AsyncPlugin;".equals(an.desc)) { isAsync = true; } } } if (plugin == null) { return null; } Map<String, Object> values = new HashMap<>(); for (int i = 0; i < plugin.values.size(); i += 2) { String key = (String) plugin.values.get(i); values.put(key, plugin.values.get(i + 1)); } String id = (String) values.get("id"); if (!ID_PATTERN.matcher(id).matches()) { logger.error("Skipping plugin with invalid plugin ID '{}' from {}. " + ID_WARNING, id); return null; } if (!isAsync) { logger.warn( "Plugin {} does not support CleanSponge's async capabilities. Missing @AsyncPlugin annotation on main plugin class.", id); return null; } return new PluginCandidate(cn.name.replace('/', '.'), values); } }