如何优化网站性能

如何优化网站性能

1.本地缓存 Caffeine

<dependency>
    <groupId>com.github.ben-manes.caffeine</groupId>
    <artifactId>caffeine</artifactId>
    <version>2.7.0</version>
</dependency>

2.配置缓存参数

#caffeine
caffeine.posts.max-size=15
caffeine.posts.expire-seconds=180

3.添加缓存代码

@Service
public class DiscussPostService {

    private static final Logger LOGGER = LoggerFactory.getLogger(DiscussPostService.class);

    @Autowired
    DiscussPostMapper discussPostMapper;

    @Autowired
    SensitiveFilter sensitiveFilter;

    @Value("${caffeine.posts.max-size}")
    private int maxSize;

    @Value("${caffeine.posts.expire-seconds}")
    private int expireSeconds;

    //Caffeine核心接口: Cache,LoadingCache,AsyncLoadingCache

    //帖子列表的缓存
    private LoadingCache<String,List<DiscussPost>> postListCache;

    //帖子总数的缓存
    private LoadingCache<Integer,Integer> postRowsCache;

    @PostConstruct
    public void init(){
        //初始化帖子列表缓存
        postListCache = Caffeine.newBuilder()
                .maximumSize(maxSize)//缓存对打的数量
                .expireAfterWrite(expireSeconds, TimeUnit.SECONDS)//缓存过期时间
                .build(new CacheLoader<String, List<DiscussPost>>() {
                    @Override
                    public @Nullable List<DiscussPost> load(@NonNull String key) throws Exception {
                        if (key == null || key.length() == 0){
                            throw new IllegalArgumentException("参数错误!");
                        }
                        String[] params = key.split(":");
                        if (params == null || params.length != 2){
                            throw new IllegalArgumentException("参数错误!");
                        }
                        int offset = Integer.valueOf(params[0]);
                        int limit = Integer.valueOf(params[1]);

                        //此处可以缓存二级缓存 this -> redis -> mysql
                        LOGGER.debug("load post list from DB.");
                        return discussPostMapper.selectDiscussPosts(0,offset,limit,1);
                    }
                });

        //初始化帖子总数缓存
        postRowsCache = Caffeine.newBuilder().maximumSize(maxSize).expireAfterWrite(expireSeconds,TimeUnit.SECONDS)
                .build(new CacheLoader<Integer, Integer>() {
                    @Override
                    public @Nullable Integer load(@NonNull Integer key) throws Exception {
                        LOGGER.debug("load post list from DB.");
                        return discussPostMapper.selectDiscussPostRows(key);
                    }
                });
    }

    public List<DiscussPost> findDiscussPosts(int userId,int page,int size,int orderMode){
        if (userId == 0 && orderMode == 1){
            return postListCache.get(page + ":" + size);
        }
        LOGGER.debug("load post list from DB.");
        return discussPostMapper.selectDiscussPosts(userId,page,size,orderMode);
    }

    public Integer findDiscussPostRows(int userId){
        if (userId == 0){
            return postRowsCache.get(userId);
        }
        LOGGER.debug("load post list from DB.");
        return discussPostMapper.selectDiscussPostRows(userId);
    }
}

性能优化前

优化后性能