feat: 添加通用附件管理功能，包括实体、服务、控制器及相关模板

aioj-backend-common/aioj-backend-common-mybatis/src/test/resources/templates/entityDO.java.ftl

@@ -0,0 +1,68 @@
+package ${package.Entity};
+
+<#list table.importPackages as pkg>
+import ${pkg};
+</#list>
+import com.baomidou.mybatisplus.annotation.*;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+import lombok.experimental.Accessors;
+import java.io.Serial;
+import java.io.Serializable;
+
+/**
+ * ${table.comment!} 数据访问对象
+ *
+ * @author ${author}
+ * @since ${date}
+ */
+@Data
+@EqualsAndHashCode(callSuper = false)
+@Accessors(chain = true)
+@TableName("${table.name}")
+public class ${entity}DO implements Serializable {
+
+    @Serial
+    private static final long serialVersionUID = 1L;
+
+<#-- 遍历字段 -->
+<#list table.fields as field>
+    <#if field.keyFlag>
+    /**
+     * ${field.comment}
+     */
+    @TableId(value = "${field.annotationColumnName}", type = IdType.ASSIGN_ID)
+    private ${field.propertyType} ${field.propertyName};
+
+    <#elseif field.propertyName == "delFlag">
+    /**
+     * ${field.comment}
+     */
+    @TableLogic
+    @TableField("${field.annotationColumnName}")
+    private ${field.propertyType} ${field.propertyName};
+
+    <#elseif field.propertyName == "createTime">
+    /**
+     * ${field.comment}
+     */
+    @TableField(value = "${field.annotationColumnName}", fill = FieldFill.INSERT)
+    private ${field.propertyType} ${field.propertyName};
+
+    <#elseif field.propertyName == "updateTime">
+    /**
+     * ${field.comment}
+     */
+    @TableField(value = "${field.annotationColumnName}", fill = FieldFill.INSERT_UPDATE)
+    private ${field.propertyType} ${field.propertyName};
+
+    <#else>
+    /**
+     * ${field.comment}
+     */
+    @TableField("${field.annotationColumnName}")
+    private ${field.propertyType} ${field.propertyName};
+
+    </#if>
+</#list>
+}