[Minor] extended Locator to get the path elements

Further added JavaDoc and removed exceptions when formatting about
locator length. This is now checked when instantiating using the builder

src/main/java/li/strolch/model/Locator.java

@@ -15,7 +15,6 @@
  */
 package li.strolch.model;
 
-import java.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -27,8 +26,9 @@ import ch.eitchnet.utils.helper.StringHelper;
 
 /**
  * <p>
- * The {@link Locator} is used to fully qualify the location of an object in the model. It consists of a {@link List} of
- * Strings which starting from the first value, defining the root, with the last item defining the objects id.
+ * The {@link Locator} is an immutable object and is used to fully qualify the location of an object in the model. It
+ * consists of a {@link List} of Strings which starting from the first value, defining the root, with the last item
+ * defining the objects id.
  * </p>
  * 
  * <p>
@@ -112,6 +112,15 @@ public class Locator {
 		this.pathElements = Collections.unmodifiableList(fullPath);
 	}
 
+	/**
+	 * Returns the immutable list of path elements making up this locator
+	 * 
+	 * @return the pathElements
+	 */
+	public List<String> getPathElements() {
+		return this.pathElements;
+	}
+
 	/**
 	 * Returns the number of elements which this {@link Locator} contains
 	 * 
@@ -185,12 +194,6 @@ public class Locator {
 	 *             if the path elements does not contain at least two items
 	 */
 	private String formatPath(List<String> pathElements) throws StrolchException {
-		if (pathElements.isEmpty()) {
-			String msg = "A Path always consists of at least 1 element: {0}"; //$NON-NLS-1$
-			msg = MessageFormat.format(msg, pathElements);
-			throw new StrolchException(msg);
-		}
-
 		StringBuilder sb = new StringBuilder();
 
 		Iterator<String> iter = pathElements.iterator();
@@ -229,6 +232,17 @@ public class Locator {
 		return true;
 	}
 
+	/**
+	 * Instantiates a new immutable {@link Locator} instance from the given string
+	 * 
+	 * @param locatorPath
+	 *            the path from which to instantiate the locator
+	 * @return the immutable {@link Locator} instance
+	 */
+	public static Locator valueOf(String locatorPath) {
+		return new Locator(locatorPath);
+	}
+
 	/**
 	 * {@link LocatorBuilder} is used to build {@link Locator}s where a deep hierarchy is to be created. The
 	 * {@link #append(String)} method returns itself for chain building
@@ -270,11 +284,13 @@ public class Locator {
 		}
 
 		/**
-		 * Creates a {@link Locator} instance with the current elements
+		 * Creates an immutable {@link Locator} instance with the current elements
 		 * 
 		 * @return a new {@link Locator} instance
 		 */
 		public Locator build() {
+			if (this.pathElements.isEmpty())
+				throw new StrolchException("The path elements must contain at least 1 item"); //$NON-NLS-1$
 			return new Locator(this.pathElements);
 		}
 	}

src/main/java/li/strolch/model/ParameterizedElement.java

@@ -192,7 +192,7 @@ public abstract class ParameterizedElement extends AbstractStrolchElement {
 
 	@Override
 	public void fillLocator(LocatorBuilder lb) {
-		lb.append(Tags.PARAMETERIZED_ELEMENT).append(this.id);
+		lb.append(this.id);
 	}
 
 	@Override

src/main/java/li/strolch/model/parameter/AbstractParameter.java

@@ -166,7 +166,7 @@ public abstract class AbstractParameter<T> extends AbstractStrolchElement implem
 
 	@Override
 	protected void fillLocator(LocatorBuilder locatorBuilder) {
-		locatorBuilder.append(Tags.PARAMETER).append(this.id);
+		locatorBuilder.append(this.id);
 	}
 
 	@Override