Initial commit

2026-04-27 18:40:30 +08:00
commit 2120774b05
112 changed files with 12308 additions and 0 deletions
@@ -0,0 +1,73 @@
+# Directory Structure
+
+> Backend directory organization for the JSP + Servlet + MySQL application.
+
+---
+
+## Overview
+
+Future backend code should follow the established B/S layered architecture.
+There is no application source tree yet; the paths and package names below are
+illustrative conventions to use when creating the first application code.
+
+---
+
+## Suggested Layout
+
+```text
+src/main/java/com/mzh/library/
+  controller/       Servlet controllers such as BookServlet
+  service/          Service interfaces such as BookService
+  service/impl/     Business implementations such as BookServiceImpl
+  dao/              DAO interfaces such as BookDao
+  dao/impl/         MySQL DAO implementations such as BookDaoImpl
+  entity/           JavaBeans/entities such as Book, Reader, BorrowRecord
+  filter/           Authentication, authorization, encoding filters
+  util/             Shared utilities such as JdbcUtil or DateUtil
+src/main/resources/
+  db.properties     MySQL connection configuration when introduced
+src/main/webapp/
+  WEB-INF/web.xml   Servlet/filter mappings when annotations are not used
+```
+
+Use the package root consistently once the first code is created. If a
+different root package is chosen in IDEA, update this spec in the same change.
+
+---
+
+## Layer Responsibilities
+
+- `controller`: Servlet classes dispatch requests, validate parameters, call
+  services, choose JSP forwards or redirects, and return results.
+- `service`: Business workflows including book warehousing/intake, borrowing,
+  returning, renewals, inventory status updates, overdue statistics, and
+  permission checks.
+- `dao`: CRUD and query access to MySQL. DAOs should not perform presentation
+  rendering or multi-step business workflows.
+- `entity`: Plain data objects representing books, categories, readers,
+  borrowing records, administrators, roles/permissions, and system logs.
+- `filter`: Cross-cutting web concerns such as login checks, role guards, and
+  request encoding.
+- `util`: Small shared helpers only after searching for existing helpers first.
+
+---
+
+## Naming Conventions
+
+- Servlet controllers use names such as `BookServlet`, `ReaderServlet`,
+  `BorrowServlet`, and `LoginServlet`.
+- Service interfaces and implementations use names such as `BookService` and
+  `BookServiceImpl`.
+- DAO interfaces and implementations use names such as `BookDao` and
+  `BookDaoImpl`.
+- Entity names should be singular Java nouns such as `Book`, `BookCategory`,
+  `Reader`, `BorrowRecord`, `Administrator`, `RolePermission`, and
+  `SystemLog`.
+
+---
+
+## Boundaries
+
+Do not put SQL in JSPs or Servlets. Do not put HTML generation in DAOs or
+services. Keep permission checks in filters/services and keep request parameter
+parsing in controllers.