完成帖子列表分页获取展示接口

my-project-backend/src/main/java/com/example/controller/ForumController.java

@@ -2,6 +2,7 @@ package com.example.controller;
 
 import com.example.entity.RestBean;
 import com.example.entity.vo.request.TopicCreateVO;
+import com.example.entity.vo.response.TopicPreviewVO;
 import com.example.entity.vo.response.TopicTypeVO;
 import com.example.entity.vo.response.WeatherVO;
 import com.example.service.TopicService;
@@ -10,6 +11,7 @@ import com.example.utils.Const;
 import com.example.utils.ControllerUtils;
 import jakarta.annotation.Resource;
 import jakarta.validation.Valid;
+import jakarta.validation.constraints.Min;
 import org.springframework.web.bind.annotation.*;
 
 import java.util.List;
@@ -49,4 +51,10 @@ public class ForumController {
                                       @RequestAttribute(Const.ATTR_USER_ID) int id) {
         return utils.messageHandle(() -> topicService.createTopic(id, vo));
     }
+
+    @GetMapping("/list-topic")
+    public RestBean<List<TopicPreviewVO>> listTopic(@RequestParam @Min(0) int page,
+                                                    @RequestParam @Min(0) int type) {
+        return RestBean.success(topicService.listTopicByPage(page, type));
+    }
 }

my-project-backend/src/main/java/com/example/entity/vo/response/TopicPreviewVO.java

@@ -0,0 +1,16 @@
+package com.example.entity.vo.response;
+
+import lombok.Data;
+
+import java.util.Date;
+import java.util.List;
+
+@Data
+public class TopicPreviewVO {
+    int id;
+    int type;
+    String title;
+    String text;
+    List<String> images;
+    Date time;
+}

my-project-backend/src/main/java/com/example/service/TopicService.java

@@ -4,10 +4,12 @@ import com.baomidou.mybatisplus.extension.service.IService;
 import com.example.entity.dto.Topic;
 import com.example.entity.dto.TopicType;
 import com.example.entity.vo.request.TopicCreateVO;
+import com.example.entity.vo.response.TopicPreviewVO;
 
 import java.util.List;
 
 public interface TopicService extends IService<Topic> {
     List<TopicType> listType();
     String createTopic(int uid, TopicCreateVO vo);
+    List<TopicPreviewVO> listTopicByPage(int pageNumber, int type);
 }

my-project-backend/src/main/java/com/example/service/impl/ImageServiceImpl.java

@@ -50,7 +50,7 @@ public class ImageServiceImpl extends ServiceImpl<ImageStoreMapper, StoreImage>
     @Override
     public String uploadImage(int id, MultipartFile file) throws IOException {
         String key = Const.FORUM_IMAGE_COUNTER + id;
-        if(flowUtils.limitPeriodCounterCheck(key, 20, 3600)) return null;
+        if(!flowUtils.limitPeriodCounterCheck(key, 20, 3600)) return null;
         String imageName = UUID.randomUUID().toString().replace("-", "");
         Date date = new Date();
         imageName = "/cache/" + format.format(date) + "/" + imageName;

my-project-backend/src/main/java/com/example/service/impl/TopicServiceImpl.java

@@ -1,21 +1,25 @@
 package com.example.service.impl;
 
+import com.alibaba.fastjson2.JSONArray;
 import com.alibaba.fastjson2.JSONObject;
+import com.baomidou.mybatisplus.core.toolkit.Wrappers;
+import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
 import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
 import com.example.entity.dto.Topic;
 import com.example.entity.dto.TopicType;
 import com.example.entity.vo.request.TopicCreateVO;
+import com.example.entity.vo.response.TopicPreviewVO;
 import com.example.mapper.TopicMapper;
 import com.example.mapper.TopicTypeMapper;
 import com.example.service.TopicService;
+import com.example.utils.CacheUtils;
 import com.example.utils.Const;
 import com.example.utils.FlowUtils;
 import jakarta.annotation.Resource;
 import org.springframework.beans.BeanUtils;
 import org.springframework.stereotype.Service;
 
-import java.util.Date;
+import java.util.*;
-import java.util.List;
 
 @Service
 public class TopicServiceImpl extends ServiceImpl<TopicMapper, Topic> implements TopicService {
@@ -26,6 +30,9 @@ public class TopicServiceImpl extends ServiceImpl<TopicMapper, Topic> implements
     @Resource
     FlowUtils flowUtils;
 
+    @Resource
+    CacheUtils cacheUtils;
+
     @Override
     public List<TopicType> listType() {
         return typeMapper.selectList(null);
@@ -36,7 +43,7 @@ public class TopicServiceImpl extends ServiceImpl<TopicMapper, Topic> implements
         if(!this.textLimitCheck(vo.getContent()))
             return "文章长度过大，发文失败！";
         String key = Const.FORUM_TOPIC_CREATE_COUNTER + uid;
-        if(flowUtils.limitPeriodCounterCheck(key, 3, 3600))
+        if(!flowUtils.limitPeriodCounterCheck(key, 3, 3600))
             return "发文频繁，请稍后再试!";
         Topic topic = new Topic();
         BeanUtils.copyProperties(vo, topic);
@@ -44,12 +51,50 @@ public class TopicServiceImpl extends ServiceImpl<TopicMapper, Topic> implements
         topic.setUid(uid);
         topic.setTime(new Date());
         if(this.save(topic)) {
+            cacheUtils.deleteCache(Const.FORUM_TOPIC_PREVIEW_CACHE + "*");
             return null;
         } else {
             return "内部错误，请联系管理员";
         }
     }
 
+    public List<TopicPreviewVO> listTopicByPage(int pageNumber, int type){
+        String key = Const.FORUM_TOPIC_PREVIEW_CACHE + pageNumber;
+        List<TopicPreviewVO> list = cacheUtils.takeListFromCache(key, TopicPreviewVO.class);
+        if(list != null) return list;
+        //无缓存从数据库读取
+        Page<Topic> page = Page.of(pageNumber, 10);
+        if(type == 0)
+            this.baseMapper.selectPage(page, null);
+        else
+            this.baseMapper.selectPage(page, Wrappers.<Topic>query().eq("type", type));
+        List<Topic> topics = page.getRecords();
+        if(topics.isEmpty()) return null;
+        list = topics.stream().map(this::resolveToPreview).toList();
+        cacheUtils.saveListToCache(key, list, 20);  //进缓存
+        return list;
+    }
+
+    private TopicPreviewVO resolveToPreview(Topic topic) {
+        TopicPreviewVO vo = new TopicPreviewVO();
+        BeanUtils.copyProperties(topic, vo);
+        List<String> images = new ArrayList<>();
+        StringBuilder previewText = new StringBuilder();
+        JSONArray ops = JSONObject.parseObject(topic.getContent()).getJSONArray("ops");
+        for (Object op : ops) {
+            Object insert = JSONObject.from(op).get("insert");
+            if(insert instanceof String text) {
+                if(previewText.length() >= 300) continue;
+                previewText.append(text);
+            } else if(insert instanceof Map<?, ?> map) {
+                Optional.ofNullable(map.get("image")).ifPresent(obj -> images.add(obj.toString()));
+            }
+        }
+        vo.setText(previewText.toString());
+        vo.setImages(images);
+        return vo;
+    }
+
     private boolean textLimitCheck(JSONObject object) {
         if(object == null) return false;
         long length = 0;

my-project-backend/src/main/java/com/example/utils/CacheUtils.java

@@ -0,0 +1,41 @@
+package com.example.utils;
+
+import com.alibaba.fastjson2.JSONArray;
+import com.alibaba.fastjson2.JSONObject;
+import jakarta.annotation.Resource;
+import org.springframework.data.redis.core.StringRedisTemplate;
+import org.springframework.stereotype.Component;
+
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+
+@Component
+public class CacheUtils {
+
+    @Resource
+    StringRedisTemplate template;
+
+    public <T> T takeFromCache(String key, Class<T> dataType) {
+        String s = template.opsForValue().get(key);
+        if(s == null) return null;
+        return JSONObject.from(s).to(dataType);
+    }
+
+    public <T> List<T> takeListFromCache(String key, Class<T> itemType) {
+        String s = template.opsForValue().get(key);
+        if(s == null) return null;
+        return JSONArray.from(s).toList(itemType);
+    }
+
+    public <T> void saveToCache(String key, T data, long expire) {
+        template.opsForValue().set(key, JSONObject.from(data).toJSONString(), expire, TimeUnit.SECONDS);
+    }
+
+    public <T> void saveListToCache(String key, T data, long expire) {
+        template.opsForValue().set(key, JSONArray.from(data).toJSONString(), expire, TimeUnit.SECONDS);
+    }
+
+    public void deleteCache(String key){
+        template.delete(key);
+    }
+}

my-project-backend/src/main/java/com/example/utils/Const.java

@@ -26,4 +26,5 @@ public final class Const {
     public final static String FORUM_IMAGE_COUNTER = "image:upload:";
     public final static String FORUM_WEATHER_CACHE = "weather:cache:";
     public final static String FORUM_TOPIC_CREATE_COUNTER = "topic:create:";
+    public final static String FORUM_TOPIC_PREVIEW_CACHE = "topic:preview:";
 }

my-project-backend/src/main/java/com/example/utils/FlowUtils.java

@@ -19,7 +19,7 @@ public class FlowUtils {
     @Resource
     StringRedisTemplate template;
 
-    private static final LimitAction defaultAction = overclock -> overclock;
+    private static final LimitAction defaultAction = overclock -> !overclock;
 
     /**
      * 针对于单次频率限制，请求成功后，在冷却时间内不得再次进行请求，如3秒内不能再次发起请求

my-project-frontend/src/views/forum/TopicList.vue

@@ -14,11 +14,13 @@ const weather = reactive({
     success: false
 })
 const editor = ref(false)
+const list = ref(null)
 
 const today = computed(() => {
     const date = new Date()
     return `${date.getFullYear()} 年 ${date.getMonth() + 1} 月 ${date.getDate()} 日`
 })
+get('/api/forum/list-topic?page=1&type=0', data => list.value = data)
 
 navigator.geolocation.getCurrentPosition(position => {
     const latitude = position.coords.latitude
@@ -48,6 +50,10 @@ navigator.geolocation.getCurrentPosition(position => {
                     <div @click="editor = true"><el-icon><EditPen/></el-icon> 点击发表主题...</div>
                 </div>
             </light-card>
+            <light-card v-for="item in list" style="margin-top: 10px">
+                <div>{{item.title}}</div>
+                <div>{{item.text}}</div>
+            </light-card>
         </div>
         <div style="width: 280px">
             <div style="position: sticky;top: 20px">