guva缓存+redis缓存应用

DevilZXx

已于 2022-10-10 09:09:36 修改

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文章标签： java

于 2022-07-01 15:46:47 首次发布

本文链接：https://blog.youkuaiyun.com/DevilZXx/article/details/125559950

本文介绍使用Guava实现本地缓存的具体案例，包括初始化配置、数据加载与刷新策略等关键环节，并对比Spring Boot自带缓存机制。

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guava本地缓存应用

我的应用场景是模糊查询框

import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.util.concurrent.ListenableFuture;
import com.kevin.demo.pojo.DeveloperCache;
import lombok.SneakyThrows;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Value;

import javax.annotation.PostConstruct;
import java.util.List;
import java.util.concurrent.TimeUnit;


public class LocalCacheDemo {

    @Value("${developer.caches.initial-capacity:3000}")
    private Integer initialCapacity;

    @Value("${developer.caches.concurrency-level:16}")
    private Integer concurrencyLevel;

    @Value("${developer.caches.maximum-size:30000}")
    private Integer maximumSize;

    @Value("${developer.caches.entry-timeout:60}")
    private Integer entryTimeout;

    private LoadingCache<String, List<DeveloperCache>> derpSynResps;

    private LoadingCache<String, List<DeveloperCache>> noDerpSynResps;

    @PostConstruct
    void initialize() {
        // derp异步信息
        derpSynRespsInit();

        // derp未异步信息
        noDerpSynRespsInit();
    }

    private void derpSynRespsInit() {
        derpSynResps = CacheBuilder.newBuilder()
                // 初始容量
            .initialCapacity(initialCapacity)
                // 并发级别
            .concurrencyLevel(concurrencyLevel)
                // 最大size
            .maximumSize(maximumSize)
                // 当缓存项上一次更新操作之后的多久会被刷新
            .refreshAfterWrite(entryTimeout, TimeUnit.SECONDS)
            .build(new CacheLoader<String, List<DeveloperCache>>() {
            @Override
            public List<DeveloperCache> load(String unused) throws Exception {
                List<DeveloperCache> developerCacheList = derpStateMapper.queryNameAndPhone();
                developerCacheList.forEach(temp -> {
                    if (!StringUtils.isEmpty(temp.getFullName())) {
                        // 解密
                        temp.setFullName(AESUtils.decrypt(temp.getFullName()));
                    }
                });
                return developerCacheList;
            }

            @Override
            public ListenableFuture<List<DeveloperCache>> reload(String key, List<DeveloperCache> oldValue)
                    throws Exception {
                return super.reload(key, oldValue);
            }
        });
    }

    private void noDerpSynRespsInit() {
        noDerpSynResps = CacheBuilder.newBuilder()
            .initialCapacity(initialCapacity)
            .concurrencyLevel(concurrencyLevel)
            .maximumSize(maximumSize)
            .refreshAfterWrite(entryTimeout, TimeUnit.SECONDS)
            .build(new CacheLoader<String, List<DeveloperCache>>() {
            @Override
            public List<DeveloperCache> load(String unused) throws Exception {
                List<DeveloperCache> developerCacheList = developerMapper.queryNameAndPhone();
                developerCacheList.forEach(temp -> {
                    if (!StringUtils.isEmpty(temp.getFullName())) {
                        temp.setFullName(AESUtils.decrypt(temp.getFullName()));
                    }
                    if (!StringUtils.isEmpty(temp.getContactEmail())) {
                        temp.setContactEmail(AESUtils.decrypt(temp.getContactEmail()));
                    }
                    if (!StringUtils.isEmpty(temp.getContactPhoneNum())) {
                        temp.setContactPhoneNum(AESUtils.decrypt(temp.getContactPhoneNum()));
                    }
                });
                return developerCacheList;
            }

            @Override
            public ListenableFuture<List<DeveloperCache>> reload(String key, List<DeveloperCache> oldValue)
                    throws Exception {
                return super.reload(key, oldValue);
            }
        });
    }

    @SneakyThrows
    private void getDeveloperList() {
        List<DeveloperCache> derpSynRespsList;
        derpSynRespsList = derpSynResps.get("");

        // TODO
    }
}

springboot自带的缓存：存储一些简单的数据结构。

只有在触发@CacheEvict(cacheNames = {DICT_LIST, DICT_VALUE}, allEntries = true)

才会更新缓存

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class SysDictServiceImpl extends ServiceImpl<SysDictDao, SysDict> implements SysDictService {
    @Autowired
    private SysDictDao sysDictDao;

    private static final String DICT_LIST = "dict:list";

    private static final String DICT_VALUE = "dict:value";

    @Override
    @Cacheable(cacheNames = DICT_LIST, key = "#code")
    public List<SysDict> getList(String code) {
        return sysDictDao.getList(code);
    }

    @Override
    @Cacheable(cacheNames = DICT_VALUE, key = "#code+'_'+#dictKey")
    public String getValue(String code, Integer dictKey) {
        return sysDictDao.getValue(code, dictKey);
    }

    @Override
    @CacheEvict(cacheNames = {DICT_LIST, DICT_VALUE}, allEntries = true)
    public void remove(List<Integer> ids) {
        ids.forEach(id -> sysDictDao.deleteById(id));
    }

    @Override
    @CacheEvict(cacheNames = {DICT_LIST, DICT_VALUE}, allEntries = true)
    public void addOrUpdate(SysDict sysDict) {
        Integer count = sysDictDao.getCount(sysDict.getCode(), sysDict.getDictKey());
        if (count > 0) {
            throw new ServiceException("当前字典键值已存在!");
        } else {
            saveOrUpdate(sysDict);
        }
    }
}

想深入了解可参考：

Redis+Guava，性能炸裂！这组合真的太顶了...._公众号-老炮说Java的博客-优快云博客