Revert the "Remove Java Plugin Framework" commits in 0.49.0, to allow external plugins to be loaded in the usual manner

gradle.properties

@@ -14,6 +14,7 @@ dependencyVersionCommonsIo=2.15.0
 # Should we be using Dbcp2?
 dependencyVersionCommonsDbcp=1.4
 dependencyVersionGuava=32.1.3-jre
+dependencyVersionJpf=1.5
 # JUnit 5 is available, some re-write required
 dependencyVersionJunit=4.13.2
 dependencyVersionMySql=8.0.33

osmosis-core/build.gradle

@@ -1,3 +1,7 @@
+dependencies {
+    implementation group: 'net.sf.jpf', name: 'jpf', version: dependencyVersionJpf
+}
+
 /*
  * Define a custom task to automatically generate the OsmosisConstants file
  * and update the java compilation task to depend on it.
@@ -28,3 +32,34 @@ task generateJavaSources {
 // Define task dependency to ensure constants file is always up to date.
 compileJava.dependsOn generateJavaSources
 sourcesJar.dependsOn generateJavaSources
+
+
+/*
+ * Define a custom task to automatically generate the plugin.xml file
+ * and update the copy resources task to depend on it.
+ */
+task generateResources {
+	description = 'Generates the plugin.xml file with the current version number.'
+
+	// Build file objects for our template file, and output java file.
+    def commonPathPrefix = "$projectDir/src/main/resources/org/openstreetmap/osmosis/core/plugin/plugin.xml"
+    def outputFile = new File(commonPathPrefix)
+    def inputFile = new File(commonPathPrefix + ".template")
+
+    /* 
+     * Declare inputs and outputs of the task to allow gradle to determine if
+     * it is up to date.
+     */
+    inputs.file inputFile
+    outputs.file outputFile
+
+    doLast {
+        // Insert the version string into the constants file.
+        def fileContent = inputFile.getText()
+        fileContent = fileContent.replace("no-version-specified", version)
+        outputFile.write(fileContent)
+    }
+}
+// Define task dependency to ensure constants file is always up to date.
+processResources.dependsOn generateResources
+sourcesJar.dependsOn generateResources

osmosis-core/src/main/java/org/openstreetmap/osmosis/core/TaskRegistrar.java

@@ -2,17 +2,31 @@
 package org.openstreetmap.osmosis.core;
 
 import java.io.BufferedReader;
+import java.io.File;
+import java.io.FilenameFilter;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
-import java.lang.reflect.InvocationTargetException;
+import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.Collections;
+import java.util.Iterator;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.logging.Logger;
 
+import org.java.plugin.JpfException;
+import org.java.plugin.ObjectFactory;
+import org.java.plugin.PluginLifecycleException;
+import org.java.plugin.PluginManager;
+import org.java.plugin.PluginManager.PluginLocation;
+import org.java.plugin.registry.Extension;
+import org.java.plugin.registry.ExtensionPoint;
+import org.java.plugin.registry.ManifestProcessingException;
+import org.java.plugin.registry.PluginDescriptor;
+import org.java.plugin.standard.StandardPluginLocation;
 import org.openstreetmap.osmosis.core.pipeline.common.TaskManagerFactory;
 import org.openstreetmap.osmosis.core.pipeline.common.TaskManagerFactoryRegister;
 import org.openstreetmap.osmosis.core.plugin.PluginLoader;
@@ -46,7 +60,7 @@ public TaskRegistrar() {
 
 	/**
 	 * Returns the configured task manager factory register configured.
-	 * 
+	 *
 	 * @return The task manager factory register.
 	 */
 	public TaskManagerFactoryRegister getFactoryRegister() {
@@ -57,7 +71,7 @@ public TaskManagerFactoryRegister getFactoryRegister() {
 	/**
 	 * Initialises factories for all tasks. Loads additionally specified plugins
 	 * as well as default tasks.
-	 * 
+	 *
 	 * @param plugins
 	 *            The class names of all plugins to be loaded.
 	 */
@@ -69,11 +83,14 @@ public void initialize(List<String> plugins) {
 		for (String plugin : plugins) {
 			loadPlugin(plugin);
 		}
+
+		// Register the plugins loaded via JPF.
+		loadJPFPlugins();
 	}
 
 	/**
 	 * Loads a plugin manually.
-	 * 
+	 *
 	 * @param pluginLoader The pluginLoader that you wish to load.
 	 */
 	public void loadPlugin(final PluginLoader pluginLoader) {
@@ -88,39 +105,38 @@ public void loadPlugin(final PluginLoader pluginLoader) {
 
 	private void loadBuiltInPlugins() {
 		final String pluginResourceName = "osmosis-plugins.conf";
-		
+
 		try {
 			for (URL pluginConfigurationUrl : Collections.list(Thread.currentThread()
 					.getContextClassLoader().getResources(pluginResourceName))) {
 				BufferedReader pluginReader;
-				
+
 				LOG.finer("Loading plugin configuration file from url " + pluginConfigurationUrl + ".");
-				
+
 				try (InputStream pluginInputStream = pluginConfigurationUrl.openStream()) {
 					if (pluginInputStream == null) {
 						throw new OsmosisRuntimeException("Cannot open URL " + pluginConfigurationUrl + ".");
 					}
-					
+
 					pluginReader = new BufferedReader(new InputStreamReader(pluginInputStream));
-					
+
 					for (;;) {
 						String plugin;
-						
+
 						plugin = pluginReader.readLine();
 						if (plugin == null) {
 							break;
 						}
-						
+
 						plugin = plugin.trim();
 						if (!plugin.isEmpty()) {
 							LOG.finer("Loading plugin via loader " + plugin + ".");
-							
+
 							loadPlugin(plugin);
 						}
 					}
 				}
 			}
-
 		} catch (IOException e) {
 			throw new OsmosisRuntimeException(
 					"Unable to load the plugins based on " + pluginResourceName
@@ -129,9 +145,165 @@ private void loadBuiltInPlugins() {
 	}
 
 
+	/**
+	 * Loads the tasks implemented as plugins.
+	 *
+	 */
+	private void loadJPFPlugins() {
+		PluginManager pluginManager;
+
+		// Create a new JPF plugin manager.
+		pluginManager = ObjectFactory.newInstance().createManager();
+
+		// Search known locations for plugin files.
+		LOG.fine("Searching for JPF plugins.");
+		List<PluginLocation> locations = gatherJpfPlugins();
+
+		// Register the core plugin.
+		LOG.fine("Registering the core plugin.");
+		registerCorePlugin(pluginManager);
+
+		// Register all located plugins.
+		LOG.fine("Registering the extension plugins.");
+		if (locations.size() == 0) {
+			// There are no plugins available so stop processing here.
+		   return;
+		}
+		registerJpfPlugins(pluginManager, locations);
+
+		// Initialise all of the plugins that have been registered.
+		LOG.fine("Activating the plugins.");
+		// load plugins for the task-extension-point
+		PluginDescriptor core = pluginManager.getRegistry()
+				.getPluginDescriptor("org.openstreetmap.osmosis.core.plugin.Core");
+
+		ExtensionPoint point = pluginManager.getRegistry().getExtensionPoint(core.getId(), "Task");
+		for (Iterator<Extension> it = point.getConnectedExtensions().iterator(); it.hasNext();) {
+
+			Extension ext = it.next();
+			PluginDescriptor descr = ext.getDeclaringPluginDescriptor();
+			try {
+				pluginManager.enablePlugin(descr, true);
+				pluginManager.activatePlugin(descr.getId());
+				ClassLoader classLoader = pluginManager.getPluginClassLoader(descr);
+				loadPluginClass(ext.getParameter("class").valueAsString(), classLoader);
+			} catch (PluginLifecycleException e) {
+				throw new OsmosisRuntimeException("Cannot load JPF-plugin '" + ext.getId()
+						+ "' for extensionpoint '" + ext.getExtendedPointId() + "'", e);
+			}
+		}
+	}
+
+
+	/**
+	 * Register the core plugin from which other plugins will extend.
+	 *
+	 * @param pluginManager
+	 *            The plugin manager to register the plugin with.
+	 */
+	private void registerCorePlugin(PluginManager pluginManager) {
+		try {
+			URL core;
+			PluginDescriptor coreDescriptor;
+
+			// Get the plugin configuration file.
+			core = getClass().getResource("/org/openstreetmap/osmosis/core/plugin/plugin.xml");
+			LOG.finest("Plugin URL: " + core);
+
+			// Register the core plugin in the plugin registry.
+			pluginManager.getRegistry().register(new URL[] {core});
+
+			// Get the plugin descriptor from the registry.
+			coreDescriptor = pluginManager.getRegistry().getPluginDescriptor(
+					"org.openstreetmap.osmosis.core.plugin.Core");
+
+			// Enable the plugin.
+			pluginManager.enablePlugin(coreDescriptor, true);
+			pluginManager.activatePlugin("org.openstreetmap.osmosis.core.plugin.Core");
+
+		} catch (ManifestProcessingException e) {
+			throw new OsmosisRuntimeException("Unable to register core plugin.", e);
+		} catch (PluginLifecycleException e) {
+			throw new OsmosisRuntimeException("Unable to enable core plugin.", e);
+		}
+	}
+
+
+	/**
+	 * Register the given JPF-plugins with the {@link PluginManager}.
+	 *
+	 * @param locations
+	 *            the plugins found
+	 */
+	private void registerJpfPlugins(PluginManager pluginManager, List<PluginLocation> locations) {
+		if (locations == null) {
+			throw new IllegalArgumentException("null plugin-list given");
+		}
+
+		try {
+			pluginManager.publishPlugins(locations.toArray(new PluginLocation[locations.size()]));
+		} catch (JpfException e) {
+			throw new OsmosisRuntimeException("Unable to publish plugins.", e);
+		}
+	}
+
+
+	/**
+	 * @return a list of all JPF-plugins found.
+	 */
+	private List<PluginLocation> gatherJpfPlugins() {
+		File[] pluginsDirs = new File[] {
+				new File("plugins"),
+				new File(System.getProperty("user.home") + "/.openstreetmap" + File.separator + "osmosis"
+						+ File.separator + "plugins"),
+				new File(System.getenv("APPDATA") + File.separator + "openstreetmap" + File.separator + "osmosis"
+						+ File.separator + "plugins")
+
+		};
+
+		FilenameFilter pluginFileNameFilter = new FilenameFilter() {
+
+			/**
+			 * @param dir
+			 *            the directory of the file
+			 * @param name
+			 *            the unqualified name of the file
+			 * @return true if this may be a plugin-file
+			 */
+			public boolean accept(final File dir, final String name) {
+				return name.toLowerCase().endsWith(".zip") || name.toLowerCase().endsWith(".jar");
+			}
+		};
+		List<PluginLocation> locations = new LinkedList<PluginLocation>();
+		for (File pluginDir : pluginsDirs) {
+			LOG.finer("Loading plugins in " + pluginDir.getAbsolutePath());
+			if (!pluginDir.exists()) {
+				continue;
+			}
+			File[] plugins = pluginDir.listFiles(pluginFileNameFilter);
+			try {
+				for (int i = 0; i < plugins.length; i++) {
+					LOG.finest("Found plugin " + plugins[i].getAbsolutePath());
+					PluginLocation location = StandardPluginLocation.create(plugins[i]);
+
+					if (location != null) {
+						locations.add(location);
+					} else {
+						LOG.warning("JPF Plugin " + plugins[i].getAbsolutePath()
+								+ " is malformed and cannot be loaded.");
+					}
+				}
+			} catch (MalformedURLException e) {
+				throw new OsmosisRuntimeException("Cannot create plugin location " + pluginDir.getAbsolutePath(), e);
+			}
+		}
+		return locations;
+	}
+
+
 	/**
 	 * Loads the tasks associated with a plugin (old plugin-api).
-	 * 
+	 *
 	 * @param plugin
 	 *            The plugin loader class name.
 	 */
@@ -149,7 +321,7 @@ private void loadPlugin(final String plugin) {
 
 	/**
 	 * Load the given plugin, old API or new JPF.
-	 * 
+	 *
 	 * @param pluginClassName
 	 *            the name of the class to instantiate
 	 * @param classLoader
@@ -175,13 +347,7 @@ private void loadPluginClass(final String pluginClassName, final ClassLoader cla
 
 		// Instantiate the plugin loader.
 		try {
-			pluginLoader = pluginClass.getDeclaredConstructor().newInstance();
-		} catch (InvocationTargetException e) {
-			throw new IllegalArgumentException("Unable to instantiate plugin class (" + pluginClassName + ").", e);
-		} catch (SecurityException e) {
-			throw new IllegalArgumentException("Unable to instantiate plugin class (" + pluginClassName + ").", e);
-		} catch (NoSuchMethodException e) {
-			throw new IllegalArgumentException("Unable to instantiate plugin class (" + pluginClassName + ").", e);
+			pluginLoader = pluginClass.newInstance();
 		} catch (InstantiationException e) {
 			throw new IllegalArgumentException("Unable to instantiate plugin class (" + pluginClassName + ").", e);
 		} catch (IllegalAccessException e) {

osmosis-core/src/main/java/org/openstreetmap/osmosis/core/plugin/CorePlugin.java

@@ -0,0 +1,30 @@
+// This software is released into the Public Domain.  See copying.txt for details.
+package org.openstreetmap.osmosis.core.plugin;
+
+import org.java.plugin.Plugin;
+
+
+/**
+ * The core plugin entry point.
+ *
+ * @author Marcus Wolschon
+ */
+public class CorePlugin extends Plugin {
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	protected void doStart() throws Exception {
+		// ignored
+	}
+
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	protected void doStop() throws Exception {
+		// ignored
+	}
+}

osmosis-core/src/main/resources/org/openstreetmap/osmosis/core/plugin/plugin.xml.template

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!DOCTYPE plugin PUBLIC "-//JPF//Java Plug-in Manifest 1.0" "http://jpf.sourceforge.net/plugin_1_0.dtd">
+<plugin id="org.openstreetmap.osmosis.core.plugin.Core" version="no-version-specified"
+	class="org.openstreetmap.osmosis.core.plugin.CorePlugin">
+	<extension-point id="Task">
+		<parameter-def id="class" />
+		<parameter-def id="name" />
+	</extension-point>
+</plugin>