Added utility methods for converting string to UTF-8 and vice versa.

briar-core/src/org/briarproject/util/StringUtils.java

 package org.briarproject.util;
 
+import java.nio.charset.Charset;
+
 public class StringUtils {
 
 	private static final char[] HEX = new char[] {
@@ -11,6 +13,14 @@ public class StringUtils {
 		return s == null || s.length() == 0;
 	}
 
+	public static byte[] toUtf8(String s) {
+		return s.getBytes(Charset.forName("UTF-8"));
+	}
+
+	public static String fromUtf8(byte[] bytes) {
+		return new String(bytes, Charset.forName("UTF-8"));
+	}
+
 	/** Converts the given byte array to a hex character array. */
 	public static char[] toHexChars(byte[] bytes) {
 		char[] hex = new char[bytes.length * 2];

briar-tests/src/org/briarproject/util/StringUtilsTest.java

@@ -7,18 +7,6 @@ import org.junit.Test;
 
 public class StringUtilsTest extends BriarTestCase {
 
-	@Test
-	public void testHead() {
-		String head = StringUtils.head("123456789", 5);
-		assertEquals("12345...", head);
-	}
-
-	@Test
-	public void testTail() {
-		String tail = StringUtils.tail("987654321", 5);
-		assertEquals("...54321", tail);
-	}
-
 	@Test
 	public void testToHexString() {
 		byte[] b = new byte[] {1, 2, 3, 127, -128};