Merge branch 'plugin-blacklist'

This adds support for blacklisting plugins from the plugin index,
even when they are present on the classpath. Initial support is via the
scijava.plugin.blacklist system property. If it proves to work well, we
can expand the public API to control the blacklist per context.

Author: ctrueden

src/main/java/org/scijava/plugin/DefaultPluginFinder.java

@@ -31,8 +31,11 @@
 
 package org.scijava.plugin;
 
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
+import java.util.regex.Pattern;
+import java.util.regex.PatternSyntaxException;
 
 import org.scijava.annotations.Index;
 import org.scijava.annotations.IndexItem;
@@ -51,6 +54,8 @@ public class DefaultPluginFinder implements PluginFinder {
 	/** Class loader to use when querying the annotation indexes. */
 	private final ClassLoader customClassLoader;
 
+	private final PluginBlacklist blacklist;
+
 	// -- Constructors --
 
 	public DefaultPluginFinder() {
@@ -59,6 +64,7 @@ public DefaultPluginFinder() {
 
 	public DefaultPluginFinder(final ClassLoader classLoader) {
 		customClassLoader = classLoader;
+		blacklist = new SysPropBlacklist();
 	}
 
 	// -- PluginFinder methods --
@@ -77,6 +83,7 @@ public HashMap<String, Throwable> findPlugins(
 
 		// create a PluginInfo object for each item in the index
 		for (final IndexItem<Plugin> item : annotationIndex) {
+			if (blacklist.contains(item.className())) continue;
 			try {
 				final PluginInfo<?> info = createInfo(item, classLoader);
 				plugins.add(info);
@@ -109,4 +116,47 @@ private ClassLoader getClassLoader() {
 		return Thread.currentThread().getContextClassLoader();
 	}
 
+	// -- Helper classes --
+
+	private interface PluginBlacklist {
+		boolean contains(String className);
+	}
+
+	/**
+	 * A blacklist defined by the {@code scijava.plugin.blacklist} system
+	 * property, formatted as a colon-separated list of regexes.
+	 * <p>
+	 * If a plugin class matches any of the regexes, it is excluded from the
+	 * plugin index.
+	 * </p>
+	 */
+	private class SysPropBlacklist implements PluginBlacklist {
+		private final List<Pattern> patterns;
+
+		public SysPropBlacklist() {
+			final String sysProp = System.getProperty("scijava.plugin.blacklist");
+			final String[] regexes = //
+				sysProp == null ? new String[0] : sysProp.split(":");
+			patterns = new ArrayList<Pattern>(regexes.length);
+			for (final String regex : regexes) {
+				try {
+					patterns.add(Pattern.compile(regex));
+				}
+				catch (final PatternSyntaxException exc) {
+					// NB: Ignore this malformed pattern.
+				}
+			}
+		}
+
+		// -- PluginBlacklist methods --
+
+		@Override
+		public boolean contains(final String className) {
+			for (final Pattern pattern : patterns) {
+				if (pattern.matcher(className).matches()) return true;
+			}
+			return false;
+		}
+	}
+
 }

src/test/java/org/scijava/plugin/PluginFinderTest.java

@@ -0,0 +1,78 @@
+/*
+ * #%L
+ * SciJava Common shared library for SciJava software.
+ * %%
+ * Copyright (C) 2009 - 2016 Board of Regents of the University of
+ * Wisconsin-Madison, Broad Institute of MIT and Harvard, and Max Planck
+ * Institute of Molecular Cell Biology and Genetics.
+ * %%
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ * #L%
+ */
+
+package org.scijava.plugin;
+
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
+
+import org.junit.Test;
+import org.scijava.Context;
+
+/**
+ * Tests {@link PluginFinder}.
+ * 
+ * @author Curtis Rueden
+ */
+public class PluginFinderTest {
+
+	/**
+	 * Tests that the {@code scijava.plugin.blacklist} system property works to
+	 * exclude plugins from the index, even when they are on the classpath.
+	 */
+	@Test
+	public void testPluginBlacklistSystemProperty() {
+		// check that the plugin is there, normally
+		Context context = new Context(PluginService.class);
+		PluginService pluginService = context.service(PluginService.class);
+		PluginInfo<SciJavaPlugin> plugin = //
+			pluginService.getPlugin(BlacklistedPlugin.class);
+		assertSame(BlacklistedPlugin.class.getName(), plugin.getClassName());
+		context.dispose();
+
+		// blacklist the plugin, then check that it is absent
+		System.setProperty("scijava.plugin.blacklist", ".*BlacklistedPlugin");
+		context = new Context(PluginService.class);
+		pluginService = context.service(PluginService.class);
+		plugin = pluginService.getPlugin(BlacklistedPlugin.class);
+		assertNull(plugin);
+		context.dispose();
+
+		// reset the system
+		System.getProperties().remove("scijava.plugin.blacklist");
+	}
+
+	@Plugin(type = SciJavaPlugin.class)
+	public static class BlacklistedPlugin implements SciJavaPlugin {
+		// NB: No implementation needed.
+	}
+
+}

src/test/java/org/scijava/plugin/PluginIndexTest.java

@@ -73,6 +73,8 @@ public void testGetPluginsOfClass() {
 		final PluginInfo<SciJavaPlugin> plugin =
 			pluginService.getPlugin(FooBar.class);
 		assertSame(testPlugin, plugin);
+
+		context.dispose();
 	}
 
 	/**
@@ -102,6 +104,8 @@ public void testGetPluginsOfClassString() {
 
 		final PluginInfo<SciJavaPlugin> plugin = pluginService.getPlugin(fakeClass);
 		assertSame(testPlugin, plugin);
+
+		context.dispose();
 	}
 
 	/** A dummy plugin for testing the plugin service. */