Encapsulate log message info in LogMessage class

Author: maarzt

src/main/java/org/scijava/log/LogMessage.java

@@ -0,0 +1,115 @@
+/*
+ * #%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.log;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Date;
+import java.util.LinkedList;
+
+/**
+ * LogMessage represents a log message.
+ *
+ * @author Matthias Arzt
+ */
+public class LogMessage {
+
+	private final int level;
+	private final String message;
+	private final Throwable throwable;
+	private final Date time;
+
+	private Collection<Object> attachments;
+
+	public LogMessage(int level, Object message,
+		Throwable throwable)
+	{
+		this.attachments = null;
+		this.level = level;
+		this.message = message == null ? null : message.toString();
+		this.throwable = throwable;
+		this.time = new Date();
+	}
+
+	public LogMessage(int level, Object msg) {
+		this(level, msg, null);
+	}
+
+	/**
+	 * Log level of the message.
+	 * 
+	 * @see LogLevel
+	 */
+	public int level() {
+		return level;
+	}
+
+	/** The content of this log message. */
+	public String text() {
+		return message;
+	}
+
+	/** Exception associated with the log message. */
+	public Throwable throwable() {
+		return throwable;
+	}
+
+	/** Time of the creation of the log message. */
+	public Date time() {
+		return time;
+	}
+
+	/**
+	 * Collection of objects that have been attached to this message with
+	 * {@link #attach(Object)}.
+	 */
+	public Collection<Object> attachments() {
+		return Collections.unmodifiableCollection(attachments);
+	}
+
+	/**
+	 * Attach object to this log message. This can be used to attach additional
+	 * information to the log message.
+	 */
+	public void attach(Object value) {
+		if (attachments == null) attachments = new LinkedList<>();
+		attachments.add(value);
+	}
+
+	// -- Object methods --
+
+	@Override
+	public String toString() {
+		return "LogMessage {" + level + ", " + message + ", " + throwable + "}";
+	}
+
+}