feat: 新增小说推荐列表查询接口

src/main/java/io/github/xxyopen/novel/controller/front/BookController.java

@@ -13,6 +13,7 @@ import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
+import java.security.NoSuchAlgorithmException;
 import java.util.List;
 
 /**
@@ -44,6 +45,14 @@ public class BookController {
         return bookService.getLastChapterAbout(bookId);
     }
 
+    /**
+     * 小说推荐列表查询接口
+     * */
+    @GetMapping("recList")
+    public RestResp<List<BookInfoRespDto>> listRecBooks(Long bookId) throws NoSuchAlgorithmException {
+        return bookService.listRecBooks(bookId);
+    }
+
     /**
      * 小说内容相关信息查询接口
      * */

src/main/java/io/github/xxyopen/novel/core/constant/CacheConsts.java

@@ -69,6 +69,11 @@ public class CacheConsts {
      */
     public static final String BOOK_CONTENT_CACHE_NAME = "bookContentCache";
 
+    /**
+     * 最近更新小说ID列表缓存
+     * */
+    public static final String LAST_UPDATE_BOOK_ID_LIST_CACHE_NAME = "lastUpdateBookIdListCache";
+
 
     /**
      * 缓存配置常量
@@ -91,7 +96,9 @@ public class CacheConsts {
 
         BOOK_CHAPTER_CACHE(0,BOOK_CHAPTER_CACHE_NAME,60 * 60 * 6,5000),
 
-        BOOK_CONTENT_CACHE(2, BOOK_CONTENT_CACHE_NAME, 60 * 60 * 12, 3000);
+        BOOK_CONTENT_CACHE(2, BOOK_CONTENT_CACHE_NAME, 60 * 60 * 12, 3000),
+
+        LAST_UPDATE_BOOK_ID_LIST_CACHE(0,LAST_UPDATE_BOOK_ID_LIST_CACHE_NAME,60 * 60, 10);
 
         /**
          * 缓存类型 0-本地 1-本地和远程 2-远程

src/main/java/io/github/xxyopen/novel/manager/BookInfoCacheManager.java

@@ -11,6 +11,8 @@ import lombok.RequiredArgsConstructor;
 import org.springframework.cache.annotation.Cacheable;
 import org.springframework.stereotype.Component;
 
+import java.util.List;
+
 /**
  * 小说信息 缓存管理类
  *
@@ -59,5 +61,17 @@ public class BookInfoCacheManager {
                 .build();
     }
 
+    /**
+     * 查询每个类别下最新更新的 500 个小说ID列表，并放入缓存中 1 个小时
+     */
+    @Cacheable(cacheManager = CacheConsts.CAFFEINE_CACHE_MANAGER
+            , value = CacheConsts.LAST_UPDATE_BOOK_ID_LIST_CACHE_NAME)
+    public List<Long> getLastUpdateIdList(Long categoryId) {
+        QueryWrapper<BookInfo> queryWrapper = new QueryWrapper<>();
+        queryWrapper.eq("category_id", categoryId)
+                .orderByDesc("last_chapter_update_time")
+                .last("limit 500");
+        return bookInfoMapper.selectList(queryWrapper).stream().map(BookInfo::getId).toList();
+    }
 
 }

src/main/java/io/github/xxyopen/novel/service/BookService.java

@@ -6,6 +6,7 @@ import io.github.xxyopen.novel.dto.resp.BookContentAboutRespDto;
 import io.github.xxyopen.novel.dto.resp.BookInfoRespDto;
 import io.github.xxyopen.novel.dto.resp.BookRankRespDto;
 
+import java.security.NoSuchAlgorithmException;
 import java.util.List;
 
 /**
@@ -45,4 +46,9 @@ public interface BookService {
      * 小说最新章节相关信息查询
      * */
     RestResp<BookChapterAboutRespDto> getLastChapterAbout(Long bookId);
+
+    /**
+     * 小说推荐列表查询
+     * */
+    RestResp<List<BookInfoRespDto>> listRecBooks(Long bookId) throws NoSuchAlgorithmException;
 }

src/main/java/io/github/xxyopen/novel/service/impl/BookServiceImpl.java

@@ -11,9 +11,14 @@ import io.github.xxyopen.novel.manager.BookInfoCacheManager;
 import io.github.xxyopen.novel.manager.BookRankCacheManager;
 import io.github.xxyopen.novel.service.BookService;
 import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Service;
 
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.util.ArrayList;
 import java.util.List;
+import java.util.Random;
 
 /**
  * 小说模块 服务实现类
@@ -23,6 +28,7 @@ import java.util.List;
  */
 @Service
 @RequiredArgsConstructor
+@Slf4j
 public class BookServiceImpl implements BookService {
 
     private final BookRankCacheManager bookRankCacheManager;
@@ -35,6 +41,8 @@ public class BookServiceImpl implements BookService {
 
     private final BookChapterMapper bookChapterMapper;
 
+    private static final Integer REC_BOOK_COUNT = 4;
+
     @Override
     public RestResp<List<BookRankRespDto>> listVisitRankBooks() {
         return RestResp.ok(bookRankCacheManager.listVisitRankBooks());
@@ -79,6 +87,27 @@ public class BookServiceImpl implements BookService {
                 .build());
     }
 
+    @Override
+    public RestResp<List<BookInfoRespDto>> listRecBooks(Long bookId) throws NoSuchAlgorithmException {
+        Long categoryId = bookInfoCacheManager.getBookInfo(bookId).getCategoryId();
+        List<Long> lastUpdateIdList = bookInfoCacheManager.getLastUpdateIdList(categoryId);
+        List<BookInfoRespDto> respDtoList = new ArrayList<>();
+        List<Integer> recIdIndexList = new ArrayList<>();
+        int count = 0;
+        Random rand = SecureRandom.getInstanceStrong();
+        while (count < REC_BOOK_COUNT){
+            int recIdIndex = rand.nextInt(lastUpdateIdList.size());
+            if (!recIdIndexList.contains(recIdIndex)) {
+                recIdIndexList.add(recIdIndex);
+                bookId = lastUpdateIdList.get(recIdIndex);
+                BookInfoRespDto bookInfo = bookInfoCacheManager.getBookInfo(bookId);
+                respDtoList.add(bookInfo);
+                count ++ ;
+            }
+        }
+        return RestResp.ok(respDtoList);
+    }
+
     @Override
     public RestResp<BookContentAboutRespDto> getBookContentAbout(Long chapterId) {
         // 查询章节信息