azkaban-memoizeit

diff --git a/src/java/azkaban/utils/PropsUtils.java b/src/java/azkaban/utils/PropsUtils.java
index e0dac83..fe2bd2c 100644
--- a/src/java/azkaban/utils/PropsUtils.java
+++ b/src/java/azkaban/utils/PropsUtils.java
@@ -24,6 +24,7 @@ import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.StringTokenizer;
 import java.util.UUID;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -31,6 +32,7 @@ import java.util.regex.Pattern;
 import azkaban.executor.ExecutableFlow;
 import azkaban.flow.CommonJobProperties;
 
+import org.apache.commons.lang.StringUtils;
 import org.joda.time.DateTime;
 
 public class PropsUtils {
@@ -147,72 +149,67 @@ public class PropsUtils {
 			.compile("\\$\\{([a-zA-Z_.0-9]+)\\}");
 
 	public static Props resolveProps(Props props) {
-		if (props == null) {
-			return null;
-		}
-
+		if (props == null) return null;
+		
 		Props resolvedProps = new Props();
-
+		
 		LinkedHashSet<String> visitedVariables = new LinkedHashSet<String>();
 		for (String key : props.getKeySet()) {
 			String value = props.get(key);
-
+			
 			visitedVariables.add(key);
-			String replacedValue = resolveVariableReplacement(value, props,
-					visitedVariables);
+			String replacedValue = resolveVariableReplacement(value, props, visitedVariables);
 			visitedVariables.clear();
-
+			
 			resolvedProps.put(key, replacedValue);
 		}
-
+		
 		return resolvedProps;
 	};
-
+	
 	private static String resolveVariableReplacement(String value, Props props, LinkedHashSet<String> visitedVariables) {
 		StringBuffer buffer = new StringBuffer();
 		int startIndex = 0;
-
+		
 		Matcher matcher = VARIABLE_PATTERN.matcher(value);
 		while (matcher.find(startIndex)) {
 			if (startIndex < matcher.start()) {
 				// Copy everything up front to the buffer
 				buffer.append(value.substring(startIndex, matcher.start()));
 			}
-
+			
 			String subVariable = matcher.group(1);
 			// Detected a cycle
 			if (visitedVariables.contains(subVariable)) {
-				throw new IllegalArgumentException(String.format(
-						"Circular variable substitution found: [%s] -> [%s]",
-						StringUtils.join(visitedVariables, "->"),
-						subVariable));
-			} else {
+				throw new IllegalArgumentException(
+						String.format("Circular variable substitution found: [%s] -> [%s]", 
+								StringUtils.join(visitedVariables.toArray(), "->"), subVariable));
+			}
+			else {
 				// Add substitute variable and recurse.
 				String replacement = props.get(subVariable);
 				visitedVariables.add(subVariable);
-
+				
 				if (replacement == null) {
 					throw new UndefinedPropertyException(
-							String.format(
-									"Could not find variable substitution for variable(s) [%s]",
-									StringUtils.join(visitedVariables, "->")));
+							String.format("Could not find variable substitution for variable(s) [%s]", 
+									StringUtils.join(visitedVariables.toArray(), "->")));
 				}
-
-				buffer.append(resolveVariableReplacement(replacement, props,
-						visitedVariables));
+				
+				buffer.append(resolveVariableReplacement(replacement, props, visitedVariables));
 				visitedVariables.remove(subVariable);
 			}
-
+			
 			startIndex = matcher.end();
 		}
-
+		
 		if (startIndex < value.length()) {
 			buffer.append(value.substring(startIndex));
 		}
-
+		
 		return buffer.toString();
 	}
-
+	
 	public static Props addCommonFlowProperties(final ExecutableFlow flow) {
 		Props parentProps = new Props();