Added bunch of javadocs and restricted some visibility.

No functional changes

src/main/java/org/scribe/extractors/AccessTokenExtractor.java

@@ -2,7 +2,18 @@ package org.scribe.extractors;
 
 import org.scribe.model.*;
 
+/**
+ * Simple command object that extracts a {@link Token} from a String
+ * 
+ * @author Pablo Fernandez
+ */
 public interface AccessTokenExtractor
 {
+  /**
+   * Extracts the access token from the contents of an Http Response
+   *  
+   * @param response the contents of the response
+   * @return OAuth access token
+   */
   public Token extract(String response);
 }

src/main/java/org/scribe/extractors/BaseStringExtractor.java

@@ -2,7 +2,20 @@ package org.scribe.extractors;
 
 import org.scribe.model.*;
 
+/**
+ * Simple command object that extracts a base string from a {@link OAuthRequest}
+ * 
+ * @author Pablo Fernandez
+ */
 public interface BaseStringExtractor
 {
+  /**
+   * Extracts an url-encoded base string from the {@link OAuthRequest}.
+   * 
+   * See <a href="http://oauth.net/core/1.0/#anchor14">the oauth spec</a> for more info on this.
+   * 
+   * @param request the OAuthRequest
+   * @return the url-encoded base string
+   */
   String extract(OAuthRequest request);
 }

src/main/java/org/scribe/extractors/BaseStringExtractorImpl.java

@@ -6,11 +6,20 @@ import org.scribe.exceptions.*;
 import org.scribe.model.*;
 import org.scribe.utils.*;
 
+/**
+ * Default implementation of {@link BaseStringExtractor}. Conforms to OAuth 1.0a
+ * 
+ * @author Pablo Fernandez
+ *
+ */
 public class BaseStringExtractorImpl implements BaseStringExtractor
 {
 
   private static final String AMPERSAND_SEPARATED_STRING = "%s&%s&%s";
 
+  /**
+   * {@inheritDoc}
+   */
   public String extract(OAuthRequest request)
   {
     checkPreconditions(request);

src/main/java/org/scribe/extractors/HeaderExtractor.java

@@ -2,7 +2,18 @@ package org.scribe.extractors;
 
 import org.scribe.model.*;
 
+/**
+ * Simple command object that generates an OAuth Authorization header to include in the request.
+ * 
+ * @author Pablo Fernandez
+ */
 public interface HeaderExtractor
 {
+  /**
+   * Generates an OAuth 'Authorization' Http header to include in requests as the signature.
+   * 
+   * @param request the OAuthRequest to inspect and generate the header
+   * @return the Http header value
+   */
   String extract(OAuthRequest request);
 }

src/main/java/org/scribe/extractors/HeaderExtractorImpl.java

@@ -6,11 +6,20 @@ import org.scribe.exceptions.*;
 import org.scribe.model.*;
 import org.scribe.utils.*;
 
+/**
+ * Default implementation of {@link HeaderExtractor}. Conforms to OAuth 1.0a
+ * 
+ * @author Pablo Fernandez
+ *
+ */
 public class HeaderExtractorImpl implements HeaderExtractor
 {
   private static final String PARAM_SEPARATOR = ", ";
   private static final String PREAMBLE = "OAuth ";
 
+  /**
+   * {@inheritDoc}
+   */
   public String extract(OAuthRequest request)
   {
     checkPreconditions(request);

src/main/java/org/scribe/extractors/RequestTokenExtractor.java

@@ -2,8 +2,18 @@ package org.scribe.extractors;
 
 import org.scribe.model.*;
 
+/**
+ * Simple command object that extracts a {@link Token} from a String
+ * 
+ * @author Pablo Fernandez
+ */
 public interface RequestTokenExtractor
 {
-
+  /**
+   * Extracts the request token from the contents of an Http Response
+   *  
+   * @param response the contents of the response
+   * @return OAuth access token
+   */
   public Token extract(String response);
 }

src/main/java/org/scribe/extractors/TokenExtractorImpl.java

@@ -6,11 +6,20 @@ import org.scribe.exceptions.*;
 import org.scribe.model.*;
 import org.scribe.utils.*;
 
+/**
+ * Default implementation of {@RequestTokenExtractor} and {@AccessTokenExtractor}. Conforms to OAuth 1.0a
+ *
+ * The process for extracting access and request tokens is similar so this class can do both things.
+ * 
+ * @author Pablo Fernandez
+ */
 public class TokenExtractorImpl implements RequestTokenExtractor, AccessTokenExtractor
 {
-
   private static final String TOKEN_REGEX = "oauth_token=(\\S*)&oauth_token_secret=(\\S*?)(&(.*))?";
 
+  /**
+   * {@inheritDoc} 
+   */
   public Token extract(String response)
   {
     Preconditions.checkEmptyString(response, "Cant extract a token from null object or an empty string.");