add core response objects

Author: SirCotare

src/main/java/it/aboutbits/springboot/toolbox/mvc/response/ErrorResponse.java

@@ -0,0 +1,13 @@
+package it.aboutbits.springboot.toolbox.mvc.response;
+
+import org.springframework.lang.Nullable;
+
+import java.util.List;
+import java.util.Map;
+
+public record ErrorResponse(
+        @Nullable String message,
+        @Nullable Map<String, List<String>> errors
+) {
+
+}

src/main/java/it/aboutbits/springboot/toolbox/mvc/response/ItemResponse.java

@@ -0,0 +1,6 @@
+package it.aboutbits.springboot.toolbox.mvc.response;
+
+import lombok.NonNull;
+
+public record ItemResponse<T>(@NonNull T data) {
+}

src/main/java/it/aboutbits/springboot/toolbox/mvc/response/ListResponse.java

@@ -0,0 +1,8 @@
+package it.aboutbits.springboot.toolbox.mvc.response;
+
+import lombok.NonNull;
+
+import java.util.List;
+
+public record ListResponse<T>(@NonNull List<T> data) {
+}

src/main/java/it/aboutbits/springboot/toolbox/mvc/response/PagedResponse.java

@@ -0,0 +1,29 @@
+package it.aboutbits.springboot.toolbox.mvc.response;
+
+import lombok.NonNull;
+import org.springframework.data.domain.Page;
+
+import java.util.List;
+
+public record PagedResponse<T>(
+        @NonNull
+        List<T> data,
+        @NonNull
+        MetaWithPagination meta
+) {
+
+    public record MetaWithPagination(
+            @NonNull
+            Pagination pagination
+    ) {
+        public record Pagination(long page, int size, long totalElements) {
+            public static Pagination of(@NonNull Page<?> page) {
+                return new Pagination(
+                        page.getNumber(),
+                        page.getSize(),
+                        page.getTotalElements()
+                );
+            }
+        }
+    }
+}