From 776e4e2390bffacec0e20236bfa986f866a14424 Mon Sep 17 00:00:00 2001
From: Anton Keks <anton@codeborne.com>
Date: Thu, 31 Jan 2013 22:37:12 +0200
Subject: [PATCH] more sophisticated plugin loader

---
 TODO                                          |  1 -
 .../ipscan/core/plugins/PluginLoader.java     | 87 ++++++++++++++++---
 2 files changed, 74 insertions(+), 14 deletions(-)

diff --git a/TODO b/TODO
index b7ea415c..396ff9d4 100644
--- a/TODO
+++ b/TODO
@@ -11,7 +11,6 @@ Before 3.0:
 * add new fetchers by configuration of PortTextFetcher
 * startup as root option
 * compile librocksaw for mac and linux64
-* plugin loader
 * public XSL for XMLExporter
 * Easier adding/removing of columns to the result table (without resetting the results)
 
diff --git a/src/net/azib/ipscan/core/plugins/PluginLoader.java b/src/net/azib/ipscan/core/plugins/PluginLoader.java
index cf5cb126..b2a2c6cd 100644
--- a/src/net/azib/ipscan/core/plugins/PluginLoader.java
+++ b/src/net/azib/ipscan/core/plugins/PluginLoader.java
@@ -3,24 +3,85 @@ package net.azib.ipscan.core.plugins;
 import net.azib.ipscan.config.LoggerFactory;
 import org.picocontainer.MutablePicoContainer;
 
+import java.io.File;
+import java.io.FilenameFilter;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.jar.Manifest;
 import java.util.logging.Logger;
 
+/**
+ * Loads plugins using two ways:
+ * <ul>
+ * <li>
+ *     Classes listed in <code>ipscan.plugins</code> system property.
+ * 	   The classes themselves must reside on the application's classpath - useful for development.
+ * </li>
+ * <li>
+ *     Jar files residing in the same directory as ipscan's binary file (jar or exe).
+ *     These jar files must have their classes listed in <code>META-INF/MANIFEST.MF</code> as <code>IPScan-Plugins</code>.
+ * </li>
+ * </ul>
+ * In either way, all plugins must implement {@link Pluggable} and one or more of the concrete interfaces.
+ */
 public class PluginLoader {
     static final Logger LOG = LoggerFactory.getLogger();
 
     public void addTo(MutablePicoContainer container) {
-        String plugins = System.getProperty("ipscan.plugins");
-        if (plugins != null) {
-            String[] classes = plugins.split("\\s*,\\s*");
-            for (String className : classes) {
-                try {
-                    Class clazz = Class.forName(className);
-                    container.registerComponentImplementation(clazz);
-                }
-                catch (ClassNotFoundException e) {
-                    LOG.warning("Unable to load plugin: " + className);
-                }
-            }
-        }
+		loadPluginsSpecifiedInSystemProperties(container);
+		loadPluginJars(container);
     }
+
+	private void loadPluginsSpecifiedInSystemProperties(MutablePicoContainer container) {
+		String plugins = System.getProperty("ipscan.plugins");
+		if (plugins != null) {
+			loadPluginClasses(container, getClass().getClassLoader(), plugins);
+		}
+	}
+
+	private void loadPluginClasses(MutablePicoContainer container, ClassLoader classLoader, String csvNames) {
+		String[] classes = csvNames.split("\\s*,\\s*");
+		for (String className : classes) {
+			try {
+				Class clazz = Class.forName(className, true, classLoader);
+				if (Pluggable.class.isAssignableFrom(clazz))
+					container.registerComponentImplementation(clazz);
+				else
+					LOG.warning("Plugin class " + clazz.getName() + " is not assignable to " + Pluggable.class.getName());
+			}
+			catch (ClassNotFoundException e) {
+				LOG.warning("Unable to load plugin: " + className);
+			}
+		}
+	}
+
+	private void loadPluginJars(MutablePicoContainer container) {
+		String ownPath = PluginLoader.class.getResource("PluginLoader.class").getFile();
+		if (ownPath.startsWith("file:")) ownPath = ownPath.substring("file:".length());
+		if (ownPath.indexOf('!') >= 0) ownPath = ownPath.substring(0, ownPath.indexOf('!'));
+		final File ownFile = new File(ownPath);
+
+		File[] jars = ownFile.getParentFile().listFiles(new FilenameFilter() {
+			@Override
+			public boolean accept(File dir, String name) {
+				return name.endsWith(".jar") && !name.equals(ownFile.getName());
+			}
+		});
+
+		for (File jar : jars) {
+			try {
+				URLClassLoader loader = new URLClassLoader(new URL[] {jar.toURI().toURL()}, PluginLoader.class.getClassLoader());
+				Manifest manifest = new Manifest(loader.getResourceAsStream("META-INF/MANIFEST.MF"));
+
+				String className = manifest.getMainAttributes().getValue("IPScan-Plugin");
+				if (className != null) loadPluginClasses(container, loader, className);
+
+				String classNames = manifest.getMainAttributes().getValue("IPScan-Plugins");
+				if (classNames != null) loadPluginClasses(container, loader, classNames);
+			}
+			catch (Exception e) {
+				LOG.warning("Failed to load plugin jar " + jar + ": " + e);
+			}
+		}
+	}
 }