String caches its hash code, so prefer HashMap to TreeMap.

components/net/sf/briar/i18n/FontManagerImpl.java

@@ -11,7 +11,6 @@ import java.util.Enumeration;
 import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
-import java.util.TreeMap;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -40,7 +39,7 @@ public class FontManagerImpl implements FontManager {
 	};
 
 	// Map from languages to fonts
-	private final Map<String, Font> fonts = new TreeMap<String, Font>();
+	private final Map<String, Font> fonts = new HashMap<String, Font>();
 
 	private volatile Font defaultFont = null, uiFont = null;
 

components/net/sf/briar/lifecycle/WindowsShutdownManagerImpl.java

 package net.sf.briar.lifecycle;
 
+import java.util.HashMap;
 import java.util.Map;
-import java.util.TreeMap;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -38,7 +38,7 @@ class WindowsShutdownManagerImpl extends ShutdownManagerImpl {
 
 	WindowsShutdownManagerImpl() {
 		// Use the Unicode versions of Win32 API calls
-		options = new TreeMap<String, Object>();
+		options = new HashMap<String, Object>();
 		options.put(Library.OPTION_TYPE_MAPPER, W32APITypeMapper.UNICODE);
 		options.put(Library.OPTION_FUNCTION_MAPPER,
 				W32APIFunctionMapper.UNICODE);

test/net/sf/briar/util/ZipUtilsTest.java

@@ -5,9 +5,10 @@ import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.Collections;
+import java.util.HashMap;
 import java.util.Map;
 import java.util.Scanner;
-import java.util.TreeMap;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipInputStream;
 import java.util.zip.ZipOutputStream;
@@ -46,14 +47,14 @@ public class ZipUtilsTest extends TestCase {
 		zip.flush();
 		zip.close();
 
-		Map<String, String> expected = new TreeMap<String, String>();
-		expected.put("abc/def", "foo bar baz");
+		Map<String, String> expected = Collections.singletonMap("abc/def",
+				"foo bar baz");
 		checkZipEntries(dest, expected);
 	}
 
 	private void checkZipEntries(File f, Map<String, String> expected)
 	throws IOException {
-		Map<String, String> found = new TreeMap<String, String>();
+		Map<String, String> found = new HashMap<String, String>();
 		assertTrue(f.exists());
 		assertTrue(f.isFile());
 		ZipInputStream unzip = new ZipInputStream(new FileInputStream(f));
@@ -108,7 +109,7 @@ public class ZipUtilsTest extends TestCase {
 		zip.flush();
 		zip.close();
 
-		Map<String, String> expected = new TreeMap<String, String>();
+		Map<String, String> expected = new HashMap<String, String>();
 		expected.put("ghi/def/1", "one one one");
 		expected.put("ghi/def/2", "two two two");
 		expected.put("ghi/3", "three three three");