added ex J

src/exercises/ex_j/Spoon.java

@@ -0,0 +1,21 @@
+package exercises.ex_j;
+
+class Spoon {
+    private Diner owner;
+
+    public synchronized Diner getOwner() {
+        return owner;
+    }
+
+    public Spoon(Diner d) {
+        owner = d;
+    }
+
+    public synchronized void setOwner(Diner d) {
+        owner = d;
+    }
+
+    public synchronized void use() {
+        System.out.printf("%s has eaten!", owner.getName());
+    }
+}