memory leak

shipping/src/main/java/com/instana/robotshop/shipping/Controller.java

@@ -1,9 +1,9 @@
 package com.instana.robotshop.shipping;
 
 import java.util.List;
-import java.util.Map;
 import java.util.Arrays;
 import java.util.ArrayList;
+import java.util.Collections;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -23,7 +23,7 @@ public class Controller {
 
     private String CART_URL = String.format("http://%s/shipping/", getenv("CART_ENDPOINT", "cart"));
 
-    public static ArrayList bytesGlobal = new ArrayList<byte[]>();
+    public static List bytesGlobal = Collections.synchronizedList(new ArrayList<byte[]>());
 
     @Autowired
     private CityRepository cityrepo;
@@ -43,6 +43,14 @@ public class Controller {
         byte[] bytes = new byte[1024 * 1024 * 25];
         Arrays.fill(bytes,(byte)8);
         bytesGlobal.add(bytes);
+
+        return bytesGlobal.size();
+    }
+
+    @GetMapping(path = "/free")
+    public int free() {
+        bytesGlobal.clear();
+
         return bytesGlobal.size();
     }