feat(sensitive-word): add DFA-based sensitive word filtering

- Add com.github.houbb:sensitive-word:0.29.5 dependency
- Create SensitiveWordFilter utility component with built-in 6W+ word bank
- Integrate into ForumService (topic title+content, comment content)
- Integrate into CommentService (article comment create + reply)
- Returns 4003 error code when sensitive words detected

Co-Authored-By: Claude <noreply@anthropic.com>

Author: yyyCode

OpenBlog-business/pom.xml

@@ -97,6 +97,13 @@
             <version>0.4.20</version>
         </dependency>
 
+        <!-- 敏感词过滤（DFA 算法） -->
+        <dependency>
+            <groupId>com.github.houbb</groupId>
+            <artifactId>sensitive-word</artifactId>
+            <version>0.29.5</version>
+        </dependency>
+
         <dependency>
             <groupId>io.minio</groupId>
             <artifactId>minio</artifactId>

OpenBlog-business/src/main/java/com/yqz/openblog/comment/service/CommentService.java

@@ -17,6 +17,7 @@
 import com.yqz.openblog.comment.repo.CommentMapper;
 import com.yqz.openblog.common.BizException;
 import com.yqz.openblog.common.PageResult;
+import com.yqz.openblog.forum.filter.SensitiveWordFilter;
 import com.yqz.openblog.user.entity.User;
 import com.yqz.openblog.user.repo.UserRepository;
 import org.springframework.stereotype.Service;
@@ -30,11 +31,14 @@ public class CommentService {
     private final CommentMapper commentMapper;
     private final ArticleMapper articleMapper;
     private final UserRepository userRepository;
+    private final SensitiveWordFilter sensitiveWordFilter;
 
-    public CommentService(CommentMapper commentMapper, ArticleMapper articleMapper, UserRepository userRepository) {
+    public CommentService(CommentMapper commentMapper, ArticleMapper articleMapper,
+                          UserRepository userRepository, SensitiveWordFilter sensitiveWordFilter) {
         this.commentMapper = commentMapper;
         this.articleMapper = articleMapper;
         this.userRepository = userRepository;
+        this.sensitiveWordFilter = sensitiveWordFilter;
     }
 
     public PageResult<CommentThreadResponse> listComments(Long articleId, int page, int size) {
@@ -163,6 +167,8 @@ private CommentUserResponse toUser(User u, Long uid) {
     }
 
     public CommentThreadResponse createTopLevel(Long articleId, Long uid, CommentCreateRequest req) {
+        checkSensitive(req.getContent());
+
         LambdaQueryWrapper<Article> articleW = Wrappers.lambdaQuery();
         articleW.eq(Article::getId, articleId).eq(Article::getStatus, ArticleStatus.PUBLISHED);
         Article article = articleMapper.selectOne(articleW);
@@ -189,6 +195,7 @@ public CommentThreadResponse createTopLevel(Long articleId, Long uid, CommentCre
 
     public CommentThreadResponse reply(Long commentId, Long uid, CommentCreateRequest req) {
         ensureUserActive(uid);
+        checkSensitive(req.getContent());
 
         Comment parent = commentMapper.selectOne(
                 Wrappers.lambdaQuery(Comment.class)
@@ -303,6 +310,13 @@ public PageResult<CommentAdminResponse> listAllComments(int page, int size, Stri
         return new PageResult<>(items, page, size, p.getTotal());
     }
 
+    private void checkSensitive(String text) {
+        if (text == null || text.isBlank()) return;
+        if (sensitiveWordFilter.contains(text)) {
+            throw new BizException(4003, "内容包含敏感词，请修改后重试");
+        }
+    }
+
     private void ensureUserActive(Long uid) {
         User u = userRepository.findById(uid).orElseThrow(() -> new BizException(4041, "用户不存在"));
         if ("BANNED".equals(u.getStatus())) {

OpenBlog-business/src/main/java/com/yqz/openblog/forum/filter/SensitiveWordFilter.java

@@ -0,0 +1,67 @@
+package com.yqz.openblog.forum.filter;
+
+import com.github.houbb.sensitive.word.bs.SensitiveWordBs;
+import com.github.houbb.sensitive.word.support.allow.WordAllows;
+import com.github.houbb.sensitive.word.support.deny.WordDenys;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+
+import java.util.List;
+
+/**
+ * 敏感词过滤器 — 基于 DFA 算法，使用 {@code com.github.houbb:sensitive-word}。
+ * <p>
+ * 主要用法：
+ * <ul>
+ *   <li>{@link #contains(String)} — 是否包含敏感词</li>
+ *   <li>{@link #findAll(String)} — 返回所有命中的敏感词</li>
+ *   <li>{@link #replace(String)} — 用 {@code *} 替换敏感词</li>
+ * </ul>
+ */
+@Component
+public class SensitiveWordFilter {
+
+    private static final Logger log = LoggerFactory.getLogger(SensitiveWordFilter.class);
+
+    private final SensitiveWordBs sw;
+
+    public SensitiveWordFilter() {
+        // 使用内置词库（6W+），后续可扩展从 DB/文件加载自定义词库
+        this.sw = SensitiveWordBs.newInstance()
+                .wordDeny(WordDenys.defaults())
+                .wordAllow(WordAllows.defaults())
+                .ignoreCase(true)
+                .ignoreWidth(true)
+                .ignoreNumStyle(true)
+                .ignoreChineseStyle(true)
+                .ignoreEnglishStyle(true)
+                .ignoreRepeat(false)
+                .init();
+        log.info("SensitiveWordFilter initialized");
+    }
+
+    /**
+     * 是否包含敏感词。
+     */
+    public boolean contains(String text) {
+        if (text == null || text.isBlank()) return false;
+        return sw.contains(text);
+    }
+
+    /**
+     * 返回命中的所有敏感词。
+     */
+    public List<String> findAll(String text) {
+        if (text == null || text.isBlank()) return List.of();
+        return sw.findAll(text);
+    }
+
+    /**
+     * 用 {@code *} 替换敏感词。
+     */
+    public String replace(String text) {
+        if (text == null || text.isBlank()) return text;
+        return sw.replace(text);
+    }
+}

OpenBlog-business/src/main/java/com/yqz/openblog/forum/service/ForumService.java

@@ -16,11 +16,13 @@
 import com.yqz.openblog.forum.entity.ForumTopicStatus;
 import com.yqz.openblog.forum.repo.ForumCommentMapper;
 import com.yqz.openblog.forum.repo.ForumTopicMapper;
+import com.yqz.openblog.forum.filter.SensitiveWordFilter;
 import com.yqz.openblog.user.entity.User;
 import com.yqz.openblog.user.repo.UserRepository;
 import org.springframework.stereotype.Service;
 
 import java.util.*;
+
 import java.util.stream.Collectors;
 
 @Service
@@ -29,11 +31,14 @@ public class ForumService {
     private final ForumTopicMapper forumTopicMapper;
     private final ForumCommentMapper forumCommentMapper;
     private final UserRepository userRepository;
+    private final SensitiveWordFilter sensitiveWordFilter;
 
-    public ForumService(ForumTopicMapper forumTopicMapper, ForumCommentMapper forumCommentMapper, UserRepository userRepository) {
+    public ForumService(ForumTopicMapper forumTopicMapper, ForumCommentMapper forumCommentMapper,
+                        UserRepository userRepository, SensitiveWordFilter sensitiveWordFilter) {
         this.forumTopicMapper = forumTopicMapper;
         this.forumCommentMapper = forumCommentMapper;
         this.userRepository = userRepository;
+        this.sensitiveWordFilter = sensitiveWordFilter;
     }
 
     /**
@@ -83,6 +88,7 @@ public ForumTopicResponse getTopic(Long topicId) {
      */
     public ForumTopicResponse createTopic(Long uid, ForumTopicCreateRequest req) {
         ensureUserActive(uid);
+        checkSensitive(req.getTitle(), req.getContent());
 
         ForumTopic topic = new ForumTopic();
         topic.setTitle(req.getTitle());
@@ -146,6 +152,7 @@ public PageResult<ForumCommentResponse> listComments(Long topicId, int page, int
      */
     public ForumCommentResponse createComment(Long topicId, Long uid, ForumCommentRequest req) {
         ensureUserActive(uid);
+        checkSensitive(req.getContent());
 
         ForumTopic topic = forumTopicMapper.selectById(topicId);
         if (topic == null || topic.getStatus() == ForumTopicStatus.HIDDEN) {
@@ -260,4 +267,14 @@ private void ensureUserActive(Long uid) {
             throw new BizException(4011, "账号已被封禁");
         }
     }
+
+    private void checkSensitive(String... texts) {
+        for (String text : texts) {
+            if (text == null || text.isBlank()) continue;
+            if (sensitiveWordFilter.contains(text)) {
+                List<String> words = sensitiveWordFilter.findAll(text);
+                throw new BizException(4003, "内容包含敏感词，请修改后重试");
+            }
+        }
+    }
 }