Added bunch of javadocs and restricted some visibility.

No functional changes

src/main/java/org/scribe/utils/MapUtils.java

@@ -2,9 +2,19 @@ package org.scribe.utils;
 
 import java.util.*;
 
+/**
+ * Utils for {@link Map} manipulation
+ * 
+ * @author Pablo Fernandez
+ */
 public class MapUtils
 {
-
+  /**
+   * Sorts a Map
+   * 
+   * @param map unsorted map
+   * @return sorted map
+   */
   public static final Map<String, String> sort(Map<String, String> map)
   {
     Preconditions.checkNotNull(map, "Cannot sort a null object.");

src/main/java/org/scribe/utils/Preconditions.java

@@ -4,27 +4,60 @@ import java.util.regex.Pattern;
 
 import org.scribe.model.OAuthConstants;
 
+/**
+ * Utils for checking preconditions and invariants
+ * 
+ * @author Pablo Fernandez
+ */
 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+");
 
+  /**
+   * Checks that an object is not null.
+   * 
+   * @param object any object
+   * @param errorMsg error message
+   * 
+   * @throws IllegalArgumentException if the object is null
+   */
   public static void checkNotNull(Object object, String errorMsg)
   {
     check(object != null, errorMsg);
   }
 
+  /**
+   * Checks that a string is not null or empty
+   * 
+   * @param string any string
+   * @param errorMsg error message
+   * 
+   * @throws IllegalArgumentException if the string is null or empty
+   */
   public static void checkEmptyString(String string, String errorMsg)
   {
     check(string != null && !string.trim().equals(""), errorMsg);
   }
 
+  /**
+   * Checks that a URL is valid
+   * 
+   * @param url any string
+   * @param errorMsg error message
+   */
   public static void checkValidUrl(String url, String errorMsg)
   {
     checkEmptyString(url, errorMsg);
     check(isUrl(url), errorMsg);
   }
   
+  /**
+   * Checks that a URL is a valid OAuth callback
+   *  
+   * @param url any string
+   * @param errorMsg error message
+   */
   public static void checkValidOAuthCallback(String url, String errorMsg)
   {
     checkEmptyString(url, errorMsg);
@@ -34,7 +67,7 @@ public class Preconditions
     }
   }
   
-  static boolean isUrl(String url)
+  private static boolean isUrl(String url)
   {
     return URL_PATTERN.matcher(url).matches();
   }

src/main/java/org/scribe/utils/StreamUtils.java

@@ -2,9 +2,19 @@ package org.scribe.utils;
 
 import java.io.*;
 
+/**
+ * Utils to deal with Streams.
+ *  
+ * @author Pablo Fernandez
+ */
 public class StreamUtils
 {
-
+  /**
+   * Returns the stream contents as an UTF-8 encoded string
+   * 
+   * @param is input stream
+   * @return string contents
+   */
   public static String getStreamContents(InputStream is)
   {
     Preconditions.checkNotNull(is, "Cannot get String from a null object");

src/main/java/org/scribe/utils/URLUtils.java

@@ -6,9 +6,13 @@ import java.util.*;
 
 import org.scribe.exceptions.*;
 
+/**
+ * Utils to deal with URL and url-encodings 
+ * 
+ * @author Pablo Fernandez
+ */
 public class URLUtils
 {
-
   private static final String EMPTY_STRING = "";
   private static final String UTF_8 = "UTF-8";
   private static final char PAIR_SEPARATOR = '=';
@@ -16,6 +20,12 @@ public class URLUtils
 
   private static final String ERROR_MSG = String.format("Cannot find specified encoding: %s", UTF_8);
 
+  /**
+   * Turns a map into a form-url-encoded string (key=value&key2=value2)
+   * 
+   * @param map any map
+   * @return form-url-encoded string
+   */
   public static String formURLEncodeMap(Map<String, String> map)
   {
     Preconditions.checkNotNull(map, "Cannot url-encode a null object");
@@ -36,6 +46,12 @@ public class URLUtils
     return encodedString.toString();
   }
 
+  /**
+   * Percent encodes a string
+   * 
+   * @param plain
+   * @return percent encoded string
+   */
   public static String percentEncode(String string)
   {
     Preconditions.checkNotNull(string, "Cannot encode null string");
@@ -49,6 +65,12 @@ public class URLUtils
     }
   }
 
+  /**
+   * Percent decodes a string
+   * 
+   * @param string percent encoded string
+   * @return plain string
+   */
   public static String percentDecode(String string)
   {
     Preconditions.checkNotNull(string, "Cannot decode null string");