新增书籍表、列表/搜索、管理员/馆员维护入口

2026-04-27 19:49:14 +08:00
parent 8777efa21d
commit 763830f767
28 changed files with 2392 additions and 8 deletions
@@ -0,0 +1,371 @@
+package com.mzh.library.controller;
+
+import com.mzh.library.dao.impl.JdbcBookDao;
+import com.mzh.library.entity.AuthenticatedUser;
+import com.mzh.library.entity.Book;
+import com.mzh.library.entity.BookCategory;
+import com.mzh.library.entity.BookSearchCriteria;
+import com.mzh.library.entity.BookStatus;
+import com.mzh.library.service.BookService;
+import com.mzh.library.service.ServiceResult;
+import com.mzh.library.service.impl.BookServiceImpl;
+import com.mzh.library.util.SessionAttributes;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.http.HttpSession;
+
+public class BookManagementServlet extends HttpServlet {
+    private static final String MANAGE_JSP = "/WEB-INF/jsp/books/manage.jsp";
+    private static final String FORM_JSP = "/WEB-INF/jsp/books/form.jsp";
+    private static final String UNAUTHORIZED_JSP = "/WEB-INF/jsp/auth/unauthorized.jsp";
+    private static final String FLASH_SUCCESS = "flashSuccess";
+    private static final String FLASH_ERROR = "flashError";
+
+    private BookService bookService;
+
+    @Override
+    public void init() {
+        this.bookService = new BookServiceImpl(new JdbcBookDao());
+    }
+
+    @Override
+    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        String path = request.getServletPath();
+        if ("/books/new".equals(path)) {
+            renderForm(request, response, "Create book", "/books", new Book(), Collections.emptyMap(),
+                Collections.emptyMap(), null);
+            return;
+        }
+        if ("/books/edit".equals(path)) {
+            showEditForm(request, response);
+            return;
+        }
+        if (!"/books".equals(path)) {
+            response.sendError(HttpServletResponse.SC_NOT_FOUND);
+            return;
+        }
+
+        showManagementList(request, response);
+    }
+
+    @Override
+    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        String path = request.getServletPath();
+        if ("/books".equals(path)) {
+            createBook(request, response);
+            return;
+        }
+        if ("/books/update".equals(path)) {
+            updateBook(request, response);
+            return;
+        }
+        if ("/books/delete".equals(path)) {
+            deleteBook(request, response);
+            return;
+        }
+
+        response.sendError(HttpServletResponse.SC_NOT_FOUND);
+    }
+
+    private void showManagementList(HttpServletRequest request, HttpServletResponse response)
+        throws ServletException, IOException {
+        BookSearchCriteria criteria = searchCriteria(request);
+        request.setAttribute("criteria", criteria);
+        applyFlash(request);
+
+        ServiceResult<List<BookCategory>> categoryResult = bookService.listCategories();
+        request.setAttribute("categories", categoryResult.isSuccessful()
+            ? categoryResult.getData()
+            : Collections.emptyList());
+        if (!categoryResult.isSuccessful()) {
+            request.setAttribute("errorMessage", categoryResult.getMessage());
+        }
+
+        ServiceResult<List<Book>> searchResult = bookService.searchBooks(criteria);
+        request.setAttribute("books", searchResult.isSuccessful()
+            ? searchResult.getData()
+            : Collections.emptyList());
+        if (!searchResult.isSuccessful()) {
+            request.setAttribute("errorMessage", searchResult.getMessage());
+            request.setAttribute("errors", searchResult.getErrors());
+        }
+
+        request.getRequestDispatcher(MANAGE_JSP).forward(request, response);
+    }
+
+    private void showEditForm(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        long id = requiredLong(request.getParameter("id"), -1L);
+        ServiceResult<Optional<Book>> result = bookService.findBook(id);
+        if (!result.isSuccessful() || !result.getData().isPresent()) {
+            flashError(request, result.isSuccessful() ? "Book was not found." : result.getMessage());
+            response.sendRedirect(request.getContextPath() + "/books");
+            return;
+        }
+
+        renderForm(request, response, "Edit book", "/books/update", result.getData().get(),
+            Collections.emptyMap(), Collections.emptyMap(), null);
+    }
+
+    private void createBook(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        BookForm form = readBookForm(request, false);
+        if (!form.getErrors().isEmpty()) {
+            renderForm(request, response, "Create book", "/books", form.getBook(), form.getValues(),
+                form.getErrors(), "Please correct the highlighted book fields.");
+            return;
+        }
+
+        ServiceResult<Long> result = bookService.createBook(currentUser(request), form.getBook());
+        if (!result.isSuccessful()) {
+            handleFormFailure(request, response, "Create book", "/books", form, result);
+            return;
+        }
+
+        flashSuccess(request, result.getMessage());
+        response.sendRedirect(request.getContextPath() + "/books");
+    }
+
+    private void updateBook(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        BookForm form = readBookForm(request, true);
+        if (!form.getErrors().isEmpty()) {
+            renderForm(request, response, "Edit book", "/books/update", form.getBook(), form.getValues(),
+                form.getErrors(), "Please correct the highlighted book fields.");
+            return;
+        }
+
+        ServiceResult<Void> result = bookService.updateBook(currentUser(request), form.getBook());
+        if (!result.isSuccessful()) {
+            handleFormFailure(request, response, "Edit book", "/books/update", form, result);
+            return;
+        }
+
+        flashSuccess(request, result.getMessage());
+        response.sendRedirect(request.getContextPath() + "/books");
+    }
+
+    private void deleteBook(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
+        long id = requiredLong(request.getParameter("id"), -1L);
+        ServiceResult<Void> result = bookService.deleteBook(currentUser(request), id);
+        if (isPermissionDenied(result)) {
+            forwardDenied(request, response, result.getMessage());
+            return;
+        }
+        if (result.isSuccessful()) {
+            flashSuccess(request, result.getMessage());
+        } else {
+            flashError(request, result.getMessage());
+        }
+        response.sendRedirect(request.getContextPath() + "/books");
+    }
+
+    private void handleFormFailure(HttpServletRequest request, HttpServletResponse response, String title,
+                                   String action, BookForm form, ServiceResult<?> result)
+        throws ServletException, IOException {
+        if (isPermissionDenied(result)) {
+            forwardDenied(request, response, result.getMessage());
+            return;
+        }
+        renderForm(request, response, title, action, form.getBook(), form.getValues(), result.getErrors(),
+            result.getMessage());
+    }
+
+    private void renderForm(HttpServletRequest request, HttpServletResponse response, String title, String action,
+                            Book book, Map<String, String> formValues, Map<String, String> errors, String errorMessage)
+        throws ServletException, IOException {
+        ServiceResult<List<BookCategory>> categoryResult = bookService.listCategories();
+        request.setAttribute("categories", categoryResult.isSuccessful()
+            ? categoryResult.getData()
+            : Collections.emptyList());
+        request.setAttribute("statuses", BookStatus.values());
+        request.setAttribute("formTitle", title);
+        request.setAttribute("formAction", action);
+        request.setAttribute("book", book);
+        request.setAttribute("formValues", formValues);
+        request.setAttribute("errors", errors);
+        if (errorMessage != null && !errorMessage.isEmpty()) {
+            request.setAttribute("errorMessage", errorMessage);
+        } else if (!categoryResult.isSuccessful()) {
+            request.setAttribute("errorMessage", categoryResult.getMessage());
+        }
+        request.getRequestDispatcher(FORM_JSP).forward(request, response);
+    }
+
+    private BookForm readBookForm(HttpServletRequest request, boolean requireId) {
+        Map<String, String> values = formValues(request);
+        Map<String, String> errors = new LinkedHashMap<>();
+        Book book = new Book();
+
+        if (requireId) {
+            book.setId(parseLong(values.get("id"), "id", "Select a valid book.", errors));
+        }
+        book.setIdentifier(values.get("identifier"));
+        book.setTitle(values.get("title"));
+        book.setAuthor(values.get("author"));
+        book.setCategoryId(parseLong(values.get("categoryId"), "categoryId", "Select a category.", errors));
+        book.setTotalCopies(parseInt(values.get("totalCopies"), "totalCopies", "Enter a valid total copy count.", errors));
+        book.setAvailableCopies(parseInt(values.get("availableCopies"), "availableCopies",
+            "Enter a valid available copy count.", errors));
+
+        try {
+            book.setStatus(BookStatus.fromCode(values.get("status")));
+        } catch (IllegalArgumentException ex) {
+            errors.put("status", "Select a status.");
+        }
+
+        return new BookForm(book, values, errors);
+    }
+
+    private Map<String, String> formValues(HttpServletRequest request) {
+        Map<String, String> values = new LinkedHashMap<>();
+        values.put("id", trim(request.getParameter("id")));
+        values.put("identifier", trim(request.getParameter("identifier")));
+        values.put("title", trim(request.getParameter("title")));
+        values.put("author", trim(request.getParameter("author")));
+        values.put("categoryId", trim(request.getParameter("categoryId")));
+        values.put("totalCopies", trim(request.getParameter("totalCopies")));
+        values.put("availableCopies", trim(request.getParameter("availableCopies")));
+        values.put("status", trim(request.getParameter("status")));
+        return values;
+    }
+
+    private BookSearchCriteria searchCriteria(HttpServletRequest request) {
+        return new BookSearchCriteria(
+            request.getParameter("identifier"),
+            request.getParameter("title"),
+            request.getParameter("author"),
+            optionalLong(request.getParameter("categoryId"))
+        );
+    }
+
+    private Long optionalLong(String value) {
+        String trimmed = trim(value);
+        if (trimmed.isEmpty()) {
+            return null;
+        }
+        try {
+            return Long.valueOf(trimmed);
+        } catch (NumberFormatException ex) {
+            return -1L;
+        }
+    }
+
+    private long parseLong(String value, String field, String message, Map<String, String> errors) {
+        String trimmed = trim(value);
+        if (trimmed.isEmpty()) {
+            errors.put(field, message);
+            return 0L;
+        }
+        try {
+            long parsed = Long.parseLong(trimmed);
+            if (parsed <= 0) {
+                errors.put(field, message);
+            }
+            return parsed;
+        } catch (NumberFormatException ex) {
+            errors.put(field, message);
+            return 0L;
+        }
+    }
+
+    private int parseInt(String value, String field, String message, Map<String, String> errors) {
+        String trimmed = trim(value);
+        if (trimmed.isEmpty()) {
+            errors.put(field, message);
+            return -1;
+        }
+        try {
+            return Integer.parseInt(trimmed);
+        } catch (NumberFormatException ex) {
+            errors.put(field, message);
+            return -1;
+        }
+    }
+
+    private long requiredLong(String value, long fallback) {
+        try {
+            long parsed = Long.parseLong(trim(value));
+            return parsed > 0 ? parsed : fallback;
+        } catch (NumberFormatException ex) {
+            return fallback;
+        }
+    }
+
+    private boolean isPermissionDenied(ServiceResult<?> result) {
+        return !result.isSuccessful() && "You do not have permission to manage books.".equals(result.getMessage());
+    }
+
+    private void forwardDenied(HttpServletRequest request, HttpServletResponse response, String message)
+        throws ServletException, IOException {
+        response.setStatus(HttpServletResponse.SC_FORBIDDEN);
+        request.setAttribute("errorMessage", message);
+        request.getRequestDispatcher(UNAUTHORIZED_JSP).forward(request, response);
+    }
+
+    private AuthenticatedUser currentUser(HttpServletRequest request) {
+        HttpSession session = request.getSession(false);
+        Object value = session == null ? null : session.getAttribute(SessionAttributes.AUTHENTICATED_USER);
+        return value instanceof AuthenticatedUser ? (AuthenticatedUser) value : null;
+    }
+
+    private void applyFlash(HttpServletRequest request) {
+        HttpSession session = request.getSession(false);
+        if (session == null) {
+            return;
+        }
+        moveFlash(session, request, FLASH_SUCCESS, "successMessage");
+        moveFlash(session, request, FLASH_ERROR, "errorMessage");
+    }
+
+    private void moveFlash(HttpSession session, HttpServletRequest request, String sessionKey, String requestKey) {
+        Object value = session.getAttribute(sessionKey);
+        if (value != null) {
+            request.setAttribute(requestKey, value);
+            session.removeAttribute(sessionKey);
+        }
+    }
+
+    private void flashSuccess(HttpServletRequest request, String message) {
+        request.getSession().setAttribute(FLASH_SUCCESS, message);
+    }
+
+    private void flashError(HttpServletRequest request, String message) {
+        request.getSession().setAttribute(FLASH_ERROR, message);
+    }
+
+    private String trim(String value) {
+        return value == null ? "" : value.trim();
+    }
+
+    private static final class BookForm {
+        private final Book book;
+        private final Map<String, String> values;
+        private final Map<String, String> errors;
+
+        private BookForm(Book book, Map<String, String> values, Map<String, String> errors) {
+            this.book = book;
+            this.values = values;
+            this.errors = errors;
+        }
+
+        private Book getBook() {
+            return book;
+        }
+
+        private Map<String, String> getValues() {
+            return values;
+        }
+
+        private Map<String, String> getErrors() {
+            return errors;
+        }
+    }
+}