Clean up parser. Add sanity checks against XML. Add documentation.

extensions/guacamole-auth-noauth/src/main/java/net/sourceforge/guacamole/net/auth/noauth/NoAuthConfigContentHandler.java

@@ -46,39 +46,96 @@ import org.xml.sax.SAXException;
 import org.xml.sax.helpers.DefaultHandler;
 
 /**
+ * XML parser for the configuration file used by the NoAuth auth provider.
  * 
  * @author Laurent Meunier
  */
 public class NoAuthConfigContentHandler extends DefaultHandler {
 
+    /**
+     * Map of all configurations, indexed by name.
+     */
     private Map<String, GuacamoleConfiguration> configs = new HashMap<String, GuacamoleConfiguration>();
+
+    /**
+     * The name of the current configuration, if any.
+     */
     private String current = null;
+
+    /**
+     * The current configuration being parsed, if any.
+     */
     private GuacamoleConfiguration currentConfig = null;
 
+    /**
+     * Returns the a map of all available configurations as parsed from the
+     * XML file. This map is unmodifiable.
+     * 
+     * @return A map of all available configurations.
+     */
     public Map<String, GuacamoleConfiguration> getConfigs() {
         return Collections.unmodifiableMap(configs);
     }
 
     @Override
     public void endElement(String uri, String localName, String qName) throws SAXException {
+
+        // If end of config element, add to map
         if (localName.equals("config")) {
+
+            // Add to map
             configs.put(current, currentConfig);
+            
+            // Reset state for next configuration
+            currentConfig = null;
+            current = null;
+            
         }
+        
     }
 
     @Override
     public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
 
+        // Begin configuration parsing if config element
         if (localName.equals("config")) {
-            current = attributes.getValue("name");
+
+            // Ensure this config is on the top level
+            if (current != null)
+                throw new SAXException("Configurations cannot be nested.");
+
+            // Read name
+            String name = attributes.getValue("name");
+            if (name == null)
+                throw new SAXException("Each configuration must have a name.");
+
+            // Read protocol
+            String protocol = attributes.getValue("protocol");
+            if (protocol == null)
+                throw new SAXException("Each configuration must have a protocol.");
+
+            // Create config stub
+            current = name;
             currentConfig = new GuacamoleConfiguration();
-            currentConfig.setProtocol(attributes.getValue("protocol"));
+            currentConfig.setProtocol(protocol);
+
         }
 
+        // Add parameters to existing configuration
         else if (localName.equals("param")) {
+
+            // Ensure a corresponding config exists
+            if (currentConfig == null)
+                throw new SAXException("Parameter without corresponding configuration.");
+
             currentConfig.setParameter(attributes.getValue("name"), attributes.getValue("value"));
+
         }
 
+        // Fail on unexpected elements
+        else
+            throw new SAXException("Unexpected element: " + localName);
+
     }
 
 }