code refactoring and suggestion for the csv parsing and merging

pom.xml

@@ -3,12 +3,6 @@
 	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 
-    <parent>
-		<groupId>org.gcube.tools</groupId>
-		<artifactId>maven-parent</artifactId>
-		<version>1.1.0</version>
-	</parent>
-
 	<groupId>org.gcube.vremanagement</groupId>
 	<artifactId>vre-removed-publisher</artifactId>
 	<version>1.0.0-SNAPSHOT</version>

src/main/java/org/gcube/vremanagement/App.java

@@ -15,14 +15,21 @@ public class App {
         XmlManager xmlManager = new XmlManager(xmlFilePath);
 
         // Parse CSV and XML files
-        csvManager.parse();
-        xmlManager.parse();
-
+        HashMap<String, Gateway> xmlMap =  xmlManager.parse();
+        HashMap<String, Gateway> csvMap =  csvManager.parse();
+       
+        
+        //Merging csvMap into the xmlMap
+        //Note that: in case of duplicate elements, the csvMap elements will overwrite the xmlMap
+        //this is ok for us because the csv elements are mode recent than xml element
+        //check this behaviour in the final xml doc 
+        xmlMap.putAll(csvMap);
+        
         // Merge CSV data into XML data structure
-        HashMap<String, ArrayList<Gateway>> mergedMap = mergeData(xmlManager.parseToHashMap(), csvManager.getGatewayMap());
+       // HashMap<String, ArrayList<Gateway>> mergedMap = mergeData(xmlManager.parseToHashMap(), csvManager.getGatewayMap());
 
         // Write merged data to final XML
-        xmlManager.writeToXml("finalDoc.xml", mergedMap);
+        xmlManager.writeToXml("finalDoc.xml", xmlMap);
 
         // Methods to query and print information
         //xmlManager.getGatewaysInfo();
@@ -31,10 +38,10 @@ public class App {
         //xmlManager.findVre("D4Science.org Detached Gateway", "D4OS", "CNROutreach");
     }
 
-    private static HashMap<String, ArrayList<Gateway>> mergeData(HashMap<String, ArrayList<Gateway>> xmlData, HashMap<String, ArrayList<Gateway>> csvData) {
+   // private static HashMap<String, ArrayList<Gateway>> mergeData(HashMap<String, ArrayList<Gateway>> xmlData, HashMap<String, ArrayList<Gateway>> csvData) {
         // Implement merging logic here
         // For simplicity, assume overwrite logic: CSV data overwrites XML data
         // You may need to implement more complex merging based on your requirements
-        return csvData;
-    }
+   //     return csvData;
+  //  }
 }

src/main/java/org/gcube/vremanagement/CsvManager.java

@@ -1,6 +1,7 @@
 package org.gcube.vremanagement;
 
 import com.opencsv.CSVReader;
+
 import com.opencsv.exceptions.CsvValidationException;
 
 import java.io.FileReader;
@@ -10,14 +11,14 @@ import java.util.HashMap;
 
 public class CsvManager {
     private String csvFilePath;
-    private HashMap<String, ArrayList<Gateway>> gatewayMap;
+    private HashMap<String, Gateway> gatewayMap;
 
     public CsvManager(String csvFilePath) {
         this.csvFilePath = csvFilePath;
         this.gatewayMap = new HashMap<>();
     }
 
-    public void parse() {
+    public HashMap<String, Gateway> parse() {
         try (CSVReader reader = new CSVReader(new FileReader(csvFilePath))) {
             String[] headers = reader.readNext(); // Read headers (optional, depending on usage)
             String[] line;
@@ -31,7 +32,7 @@ public class CsvManager {
                 String description = line[6];
 
                 // Extract gateway name from URL
-                String gatewayName = extractGatewayName(gateways);
+                String gatewayName = this.extractGatewayName(gateways);
 
                 // Ensure gateway exists in the HashMap
                 Gateway gateway = gatewayMap.computeIfAbsent(gatewayName, k -> new ArrayList<>()).stream()
@@ -67,12 +68,16 @@ public class CsvManager {
                     }});
                 }
             }
+            
+            return gatewayMap;
         } catch (IOException | CsvValidationException e) {
             e.printStackTrace();
         }
+        
+        return null;
     }
 
-    public HashMap<String, ArrayList<Gateway>> getGatewayMap() {
+    public HashMap<String, Gateway> getGatewayMap() {
         return gatewayMap;
     }
 

src/main/java/org/gcube/vremanagement/VreRemPubInterface.java

@@ -1,8 +1,11 @@
 package org.gcube.vremanagement;
 
+import java.util.ArrayList;
+import java.util.HashMap;
+
 public interface VreRemPubInterface {
 
-	void parse(); //method used to parse the file (e.g., xml or csv) in a data structure
+	HashMap<String, Gateway> parse(); //method used to parse the file (e.g., xml or csv) in a data structure
 	void update(); //method used to update the file (e.g., xml or csv)
 	//add here other common methods needed by both Csv and Xml Manager
 	void find();

src/main/java/org/gcube/vremanagement/XmlManager.java

@@ -27,7 +27,7 @@ public class XmlManager implements VreRemPubInterface {
 	}
 
 	@Override
-	public void parse() {
+	public HashMap<String, Gateway> parse() {
 		try {
 			File xmlFile = new File(filePath);
 			DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
@@ -135,9 +135,11 @@ public class XmlManager implements VreRemPubInterface {
 					//computeIfAbsent(gatewayName, k -> new ArrayList<>()).add(gateway);
 				}
 			}
+			return gatewaysMap;
 		} catch (Exception e) {
 			e.printStackTrace();
 		}
+		return null;
 	}
 	public void getGatewaysInfo() {
 		System.out.println("Name of the Gateway:");