Made arbitraryDataFileHashResponses final, and use .sort() rather than .stream() to avoid new instance creation.

src/main/java/org/qortal/controller/arbitrary/ArbitraryDataFileManager.java

@@ -48,7 +48,7 @@ public class ArbitraryDataFileManager extends Thread {
     /**
      * List to keep track of any arbitrary data file hash responses
      */
-    public List<ArbitraryFileListResponseInfo> arbitraryDataFileHashResponses = Collections.synchronizedList(new ArrayList<>());
+    public final List<ArbitraryFileListResponseInfo> arbitraryDataFileHashResponses = Collections.synchronizedList(new ArrayList<>());
 
     /**
      * List to keep track of peers potentially available for direct connections, based on recent requests

src/main/java/org/qortal/controller/arbitrary/ArbitraryDataFileRequestThread.java

@@ -55,9 +55,7 @@ public class ArbitraryDataFileRequestThread implements Runnable {
                 // Sort by lowest number of node hops first
                 Comparator<ArbitraryFileListResponseInfo> lowestHopsFirstComparator =
                         Comparator.comparingInt(ArbitraryFileListResponseInfo::getRequestHops);
-                List<ArbitraryFileListResponseInfo> sortedResponses = arbitraryDataFileManager.arbitraryDataFileHashResponses
-                        .stream().sorted(lowestHopsFirstComparator).collect(Collectors.toList());
-                arbitraryDataFileManager.arbitraryDataFileHashResponses = Collections.synchronizedList(sortedResponses);
+                arbitraryDataFileManager.arbitraryDataFileHashResponses.sort(lowestHopsFirstComparator);
 
                 Iterator iterator = arbitraryDataFileManager.arbitraryDataFileHashResponses.iterator();
                 while (iterator.hasNext()) {