com.crawljax.web.fs.PluginManager Maven / Gradle / Ivy

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package com.crawljax.web.fs;

import com.crawljax.core.plugin.descriptor.PluginDescriptor;
import com.crawljax.web.di.CrawljaxWebModule;
import com.crawljax.web.exception.CrawljaxWebException;
import com.crawljax.web.model.Plugin;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.inject.Inject;
import javax.inject.Singleton;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FilenameFilter;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

@Singleton
public class PluginManager {

	private static final Logger LOG = LoggerFactory.getLogger(PluginManager.class);

	private final File pluginsFolder;
	
	@Inject
	public PluginManager(@CrawljaxWebModule.PluginsFolder File pluginsFolder) {
		this.pluginsFolder = pluginsFolder;
		if (!this.pluginsFolder.exists())
			this.pluginsFolder.mkdirs();
	}

	public ConcurrentHashMap loadAll() {
		ConcurrentHashMap plugins = new ConcurrentHashMap<>();
		List pluginIds = new ArrayList<>();

		File[] locators = pluginsFolder.listFiles(new FilenameFilter() {
			public boolean accept(File dir, String name) {
				return name.endsWith(".locator");
			}
		});
		for(File locator : locators) {
			pluginIds.add(locator.getName().substring(0, locator.getName().indexOf(".locator")));
		}

		File[] jars = pluginsFolder.listFiles(new FilenameFilter() {
			public boolean accept(File dir, String name) {
				return name.endsWith(".jar");
			}
		});
		for(File jar : jars) {
			String id = jar.getName().substring(0, jar.getName().indexOf(".jar"));
			if(!pluginIds.contains(id)) {
				pluginIds.add(id);
			}
		}

		for (String id : pluginIds) {
			Plugin p = load(id);
			if(p != null) {
				plugins.put(p.getId(), p);
			}
		}

		return plugins;
	}

	private String readTextFile(File file) {
		String result = null;
		try(FileReader reader = new FileReader(file)) {
			try(BufferedReader br = new BufferedReader(reader)) {
				StringBuilder sb = new StringBuilder();
				String line = br.readLine();

				while (line != null) {
					sb.append(line);
					sb.append('\n');
					line = br.readLine();
				}
				result = sb.toString();
			} catch (IOException e) {
				LOG.error(e.toString());
				LOG.debug(e.toString());
			}
		} catch (IOException e) {
			LOG.error(e.toString());
			LOG.debug(e.toString());
		}
		return result;
	}

	private File download(URL source, File destination) {
		if(destination.exists()) {
			destination.delete();
		}
		try {
			destination.createNewFile();
			try(ReadableByteChannel rbc = Channels.newChannel(source.openStream())) {
				try(FileOutputStream fos = new FileOutputStream(destination)) {
					fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
					fos.flush();
				}
			}
		} catch (Exception e) {
			LOG.error(e.toString());
			LOG.debug(e.toString());
		}
		return destination;
	}

	public Plugin load(String pluginId) {
		File jar = loadPluginJar(pluginId);
		Plugin plugin = null;
		try {
			PluginDescriptor descriptor = loadPluginDescriptorFromJar(jar);
			if(descriptor == null) {
				throw new Exception("Failed to load plugin descriptor");
			}
			plugin = new Plugin();
			plugin.setId(pluginId);
			plugin.setJarFile(jar);
			plugin.setName(descriptor.getName());
			plugin.setDescription(descriptor.getDescription());
			plugin.setParameters(descriptor.getParameters());
			plugin.setCrawljaxVersions(descriptor.getCrawljaxVersions());
		} catch (Exception e) {
			LOG.error("Could not load plugin {}", jar.getName());
			LOG.debug("Could not load plugin {}. \n{}", jar.getName(), e.getStackTrace());
		}
		return plugin;
	}

	private File loadPluginJar(String pluginId) {
		File locator = new File(pluginsFolder, pluginId + ".locator");
		File jar = new File(pluginsFolder, pluginId + ".jar");
		if(locator.exists()) {
			try {
				URL url = new URL(readTextFile(locator).trim());
				jar = download(url, jar);
			} catch (MalformedURLException e) {
				LOG.error(e.toString());
				LOG.debug(e.toString());
			}
		}
		return jar;
	}

	private PluginDescriptor loadPluginDescriptorFromJar(File jarFile) {
		PluginDescriptor pluginDescriptor = null;
		try {
			try(ZipFile zipFile = new ZipFile(jarFile)) {
				ZipEntry descriptorEntry = zipFile.getEntry("plugin-descriptor.xml");
				if(descriptorEntry == null) {
					throw new Exception("Could not find plugin-descriptor.xml in root of " + jarFile.getName());
				}
				try(InputStream is = zipFile.getInputStream(zipFile.getEntry("plugin-descriptor.xml"))) {
					pluginDescriptor = PluginDescriptor.fromXMLStream(is);
				}
			}
		}  catch (Exception e) {
			LOG.error("Could not load plugin descriptor in {}. ", jarFile.getName());
			LOG.debug("Could not load plugin descriptor in {}. \n{}", jarFile.getName(), e.getStackTrace());
		}
		return pluginDescriptor;
	}

	public Plugin save(String id, byte[] data) throws CrawljaxWebException {
		File pluginJar = new File(pluginsFolder, id + ".jar");
		try {
			if (pluginJar.exists()) {
				pluginJar.delete();
			}
			pluginJar.createNewFile();
			try(FileOutputStream fos = new FileOutputStream(pluginJar)) {
				fos.write(data);
				fos.flush();
			}
		} catch (IOException e) {
			LOG.error("Could not save plugin file {}.", pluginJar.getName());
			LOG.debug("Could not save plugin file {}.\n{}", pluginJar.getName(), e.getStackTrace());
			throw new CrawljaxWebException("Could not save plugin file");
		}

		Plugin plugin = load(id);
		if(plugin == null) {
			delete(id);
			throw new CrawljaxWebException("Could not read plugin descriptor");
		}

		return plugin;
	}

	public Plugin save(String id, URL url) throws CrawljaxWebException {
		File urlFile = new File(pluginsFolder, id + ".locator");
		try {
			if (urlFile.exists()) {
				urlFile.delete();
			}
			urlFile.createNewFile();
			try(FileOutputStream fos = new FileOutputStream(urlFile)) {
				fos.write(url.toExternalForm().getBytes());
				fos.flush();
			}
		} catch (IOException e) {
			urlFile.delete();
			LOG.error(e.toString());
			LOG.debug(e.toString());
			throw new CrawljaxWebException("Could not save plugin file");
		}
		Plugin plugin = load(id);
		if(plugin == null) {
			delete(id);
			throw new CrawljaxWebException("Could not read plugin descriptor");
		}
		return plugin;
	}

	public boolean delete(String id) {
		File pluginLocator = new File(pluginsFolder, id + ".locator");
		boolean removedPL = true;
		if(pluginLocator.exists()) {
			removedPL = pluginLocator.delete();
			if(!removedPL) {
				LOG.error("Failed to delete plugin file: " + pluginLocator);
				LOG.debug("Failed to delete plugin file: " + pluginLocator);
			}
		}
		File pluginJar = new File(pluginsFolder, id + ".jar");
		boolean removedJar = pluginJar.delete();
		if(!removedJar) {
			LOG.error("Failed to delete plugin file: " + pluginJar);
			LOG.debug("Failed to delete plugin file: " + pluginJar);
		}
		return removedPL && removedJar;
	}
}