Add AtomicString class for atomic string manipulation

Author: marioserrano09

platform/core/commons/src/main/java/tools/dynamia/commons/AtomicString.java

@@ -0,0 +1,27 @@
+package tools.dynamia.commons;
+
+import java.util.concurrent.atomic.AtomicReference;
+
+public class AtomicString extends AtomicReference<String> {
+
+    public static AtomicString of(String string) {
+        return new AtomicString(string);
+    }
+
+    public static AtomicString empty() {
+        return new AtomicString("");
+    }
+
+
+    public AtomicString() {
+        super(null);
+    }
+
+    public AtomicString(String initialValue) {
+        super(initialValue);
+    }
+
+    public String append(String string) {
+        return updateAndGet(current -> current == null ? string : current + string);
+    }
+}