Add LoggerPreprocessor to inject Logger instances

This PreprocessorPlugin affects modules with a single Parameter
of type Logger. It will get a logger from LogService, named
like the module's class, and assign it to the Parameter.

Author: maarzt

src/main/java/org/scijava/module/process/LoggerPreprocessor.java

@@ -0,0 +1,74 @@
+/*
+ * #%L
+ * SciJava Common shared library for SciJava software.
+ * %%
+ * Copyright (C) 2009 - 2017 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.module.process;
+
+import org.scijava.log.LogService;
+import org.scijava.log.Logger;
+import org.scijava.module.Module;
+import org.scijava.module.ModuleItem;
+import org.scijava.module.ModuleService;
+import org.scijava.plugin.Parameter;
+import org.scijava.plugin.Plugin;
+
+/**
+ * This {@link PreprocessorPlugin} affects {@link Module}s with a single
+ * {@link Parameter} of type {@link Logger}. It will assign a Logger to that
+ * Parameter, that is named like the modules class.
+ *
+ * @author Matthias Arzt
+ */
+@Plugin(type = PreprocessorPlugin.class)
+public class LoggerPreprocessor extends AbstractPreprocessorPlugin {
+
+	@Parameter(required = false)
+	private LogService logService;
+
+	@Parameter(required = false)
+	private ModuleService moduleService;
+
+	// -- ModuleProcessor methods --
+
+	@Override
+	public void process(final Module module) {
+		if (logService == null || moduleService == null) return;
+
+		final ModuleItem<?> loggerInput = moduleService.getSingleInput(module,
+			Logger.class);
+		if (loggerInput == null || !loggerInput.isAutoFill()) return;
+
+		final String name = loggerInput.getName();
+		module.setInput(name, logService.subLogger(module.getDelegateObject()
+			.getClass().getSimpleName()));
+		module.resolveInput(name);
+	}
+
+}

src/test/java/org/scijava/module/process/LoggerPreprocessorTest.java

@@ -0,0 +1,81 @@
+/*
+ * #%L
+ * SciJava Common shared library for SciJava software.
+ * %%
+ * Copyright (C) 2009 - 2017 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.module.process;
+
+import static org.junit.Assert.assertTrue;
+
+import java.util.concurrent.ExecutionException;
+
+import org.junit.Test;
+import org.scijava.Context;
+import org.scijava.command.Command;
+import org.scijava.command.CommandModule;
+import org.scijava.command.CommandService;
+import org.scijava.log.LogService;
+import org.scijava.log.Logger;
+import org.scijava.log.TestLogListener;
+import org.scijava.plugin.Parameter;
+import org.scijava.plugin.Plugin;
+
+/**
+ * Tests {@link LoggerPreprocessor}.
+ *
+ * @author Matthias Arzt
+ */
+public class LoggerPreprocessorTest {
+
+	@Test
+	public void testInjection() throws InterruptedException, ExecutionException {
+		final Context context = new Context(CommandService.class);
+		final CommandService commandService = context.service(CommandService.class);
+		final LogService logService = context.service(LogService.class);
+		final TestLogListener listener = new TestLogListener();
+		logService.addListener(listener);
+
+		final CommandModule module = //
+				commandService.run(CommandWithLogger.class, true).get();
+		assertTrue(listener.hasLogged(m -> m.source().path().contains(CommandWithLogger.class.getSimpleName())));
+	}
+
+	@Plugin(type = Command.class)
+	public static class CommandWithLogger implements Command {
+
+		@Parameter
+		public Logger log;
+
+		@Override
+		public void run() {
+			log.info("log from the command.");
+		}
+	}
+
+}