gistfile1.diff

diff --git a/src/main/java/org/scribe/utils/Preconditions.java b/src/main/java/org/scribe/utils/Preconditions.java
index de22b4e..06bd151 100644
--- a/src/main/java/org/scribe/utils/Preconditions.java
+++ b/src/main/java/org/scribe/utils/Preconditions.java
@@ -1,10 +1,13 @@
 package org.scribe.utils;
 
+import java.util.regex.Pattern;
+
 import org.scribe.model.OAuthConstants;
 
 public class Preconditions
 {
   private static final String DEFAULT_MESSAGE = "Received an invalid parameter";
+  private static final Pattern URL_PATTERN = Pattern.compile("[a-zA-Z]+://\\S+");
 
   public static void checkNotNull(Object object, String errorMsg)
   {
@@ -33,7 +36,7 @@ public class Preconditions
   
   static boolean isUrl(String url)
   {
-    return url.startsWith("http://") || url.startsWith("https://");
+    return URL_PATTERN.matcher(url).matches();
   }
   
   private static void check(boolean requirements, String error)
diff --git a/src/test/java/org/scribe/utils/PreconditionsTest.java b/src/test/java/org/scribe/utils/PreconditionsTest.java
index f2290a3..0add2f6 100644
--- a/src/test/java/org/scribe/utils/PreconditionsTest.java
+++ b/src/test/java/org/scribe/utils/PreconditionsTest.java
@@ -53,6 +53,17 @@ public class PreconditionsTest
     Preconditions.checkValidUrl("https://www.example.com", ERROR_MSG);
   }
   
+  public void shouldAllowNonStandarProtocolsForAndroid()
+  {
+    Preconditions.checkValidUrl("myUrl://www.example.com", ERROR_MSG);
+  }
+  
+  @Test(expected = IllegalArgumentException.class)
+  public void shouldNotAllowStrangeProtocolNames()
+  {
+    Preconditions.checkValidUrl("_weird*://www.example.com", ERROR_MSG);
+  }
+  
   public void shouldAllowOutOfBandAsValidCallbackValue()
   {
     Preconditions.checkValidOAuthCallback("oob", ERROR_MSG);