种子，促销
Change-Id: I0ce919ce4228dcefec26ef636bacd3298c0dc77a
diff --git a/src/main/java/com/example/myproject/entity/EntityBase.java b/src/main/java/com/example/myproject/entity/EntityBase.java
new file mode 100644
index 0000000..48583cb
--- /dev/null
+++ b/src/main/java/com/example/myproject/entity/EntityBase.java
@@ -0,0 +1,61 @@
+package com.example.myproject.entity;
+
+
+
+import com.baomidou.mybatisplus.annotation.IdType;
+import com.baomidou.mybatisplus.annotation.TableId;
+
+import java.util.Objects;
+
+import lombok.Getter;
+import lombok.Setter;
+
+/**
+ * Base class for an entity, as explained in the book "Domain Driven Design".
+ * All entities in this project have an identity attribute with type Long and
+ * name id. Inspired by the DDD Sample project.
+
+ */
+@Setter
+@Getter
+public abstract class EntityBase {
+
+ /**
+ * This identity field has the wrapper class type Long so that an entity which
+ * has not been saved is recognizable by a null identity.
+ */
+ @TableId(type = IdType.AUTO)
+ private Integer id;
+
+ @Override
+ public boolean equals(final Object object) {
+ if (!(object instanceof EntityBase)) {
+ return false;
+ }
+ if (!getClass().equals(object.getClass())) {
+ return false;
+ }
+ final EntityBase that = (EntityBase) object;
+ _checkIdentity(this);
+ _checkIdentity(that);
+ return this.id.equals(that.getId());
+ }
+
+
+ private void _checkIdentity(final EntityBase entity) {
+ if (entity.getId() == null) {
+ throw new IllegalStateException("Comparison identity missing in entity: " + entity);
+ }
+ }
+
+ @Override
+ public int hashCode() {
+ return Objects.hash(this.getId());
+ }
+
+ @Override
+ public String toString() {
+ return this.getClass().getSimpleName() + "<" + getId() + ">";
+ }
+
+}