Add a location type backed by a URI

Author: ctrueden

src/main/java/org/scijava/io/URILocation.java

@@ -0,0 +1,126 @@
+/*
+ * #%L
+ * SciJava Common shared library for SciJava software.
+ * %%
+ * Copyright (C) 2009 - 2015 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.io;
+
+import java.io.UnsupportedEncodingException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.URLDecoder;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import org.scijava.log.LogService;
+import org.scijava.plugin.Parameter;
+
+/**
+ * {@link Location} backed by a {@link URI} string.
+ * 
+ * @author Curtis Rueden
+ */
+public class URILocation extends AbstractLocation {
+
+	@Parameter
+	private LogService log;
+
+	private final URI uri;
+
+	public URILocation(final URI uri) {
+		this.uri = uri;
+	}
+
+	public URILocation(final String uriPath) throws URISyntaxException {
+		this(new URI(uriPath));
+	}
+
+	// -- URILocation methods --
+
+	public Map<String, String> getQueryMap() {
+		return decodeQuery(getURI().getRawQuery());
+	}
+
+	public String getQueryValue(final String key) {
+		return getQueryMap().get(key);
+	}
+
+	// FIXME: look up whether anyone has created a mutatable URI class,
+	// with individual setters for the various parts. Otherwise, we'll
+	// have to handle it here!
+
+	// -- Location methods --
+
+	@Override
+	public URI getURI() {
+		return uri;
+	}
+
+	// -- Helper methods --
+
+	/**
+	 * Decodes a query string of ampersand-separated key/value pairs. E.g.:
+	 * {@code apples=yummy&bananas=delicious&grapefruits=scrumptious}.
+	 * 
+	 * @param query The query string to decode.
+	 * @return A map of the decoded key/value pairs.
+	 */
+	private Map<String, String> decodeQuery(final String query) {
+		final Map<String, String> map = new LinkedHashMap<String, String>();
+		if (query == null) return map;
+		for (final String param : query.split("&")) {
+			final int equals = param.indexOf("=");
+			if (equals < 0) {
+				map.put(decode(param), "true");
+			}
+			else {
+				final String key = decode(param.substring(0, equals));
+				final String value = decode(param.substring(equals + 1));
+				map.put(key, value);
+			}
+		}
+		return map;
+	}
+
+	/**
+	 * Decodes a single uuencoded string.
+	 * 
+	 * @see URLDecoder
+	 */
+	private String decode(final String s) {
+		// http://stackoverflow.com/a/6926987
+		try {
+			return URLDecoder.decode(s.replace("+", "%2B"), "UTF-8");
+		}
+		catch (UnsupportedEncodingException exc) {
+			return null;
+		}
+	}
+
+}