ehcache：Null key returned for cache operation问题解决方法

﹏ヽ暗。殇╰゛Y 2022-12-10 11:26 223阅读 0赞

## 前言 ##

今天一个上线许久的系统突然`无法新增`证书，但是不是所有都不允许新增，只是编号重复的无法新增。从`逻辑`上想，我是设置了编号`重复判断`，但是该业务判断逻辑未生效，从`缓存`上将，会不会是`id=null`导致的问题。

**报错详情**：

java.lang.IllegalArgumentException: Null key returned for cache operation (maybe you are using named params on classes without debug info?) Builder[public java.lang.Object com.egag.cert.controller.CertCompanyController.save(com.egag.cert.entity.CertCompany)] caches=[cache-certCompany] | key='#certCompany.certId' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='',false,false
            at org.springframework.cache.interceptor.CacheAspectSupport.generateKey(CacheAspectSupport.java:578)
            at org.springframework.cache.interceptor.CacheAspectSupport.performCacheEvict(CacheAspectSupport.java:492)
            at org.springframework.cache.interceptor.CacheAspectSupport.processCacheEvicts(CacheAspectSupport.java:476)
            at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:433)
    
            at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:345)
    
            at org.springframework.cache.interceptor.CacheInterceptor.invoke(CacheInterceptor.java:61)

## 检查思路 ##

报错信息非常清晰，首先是`缓存报错`，另一方面是发生在`新增的情况（id = null / 0）` 且`编号重复`的情况，编辑旧的数据则不会影响。

思来想去莫非是新增的对象在缓存中判断不严谨，因为我们重点在于更新旧的数据，新的数据查询的时候自己加载到缓存就可以了。于是我们需要增加一个`condition`的参数。

/** * 新增或编辑 */
        @PostMapping("/save")
        @CacheEvict(value = EhCacheUtil.CACHE_NAME_CERT_COMPANY, key = EhCacheUtil.CACHE_KEY_CERT_COMPANY_OBJ)
        public Object save(@RequestBody CertCompany certCompany){ 
            log.info("certCompany:"+JSON.toJSONString(certCompany));
            CertCompany oldCertCompany = certCompanyMapper.selectOne(new QueryWrapper<CertCompany>().eq("cert_id",certCompany.getCertId()));
            certCompany.setUpdateTime(new Date());
            if(oldCertCompany!=null){ 
                certCompanyMapper.updateById(certCompany);
            }else{ 
                if(certCompanyMapper.selectOne(new QueryWrapper<CertCompany>().eq("cert_number",certCompany.getCertNumber()))!=null){ 
                    return ReturnT.ERROR("保存失败，名字重复");
                }
                //创建MiniCode
                certCompanyMapper.insert(certCompany);
            }
            //省略部分业务逻辑
            //清空列表缓存
            cacheService.cleanCompanyListByPageLimit();
            return ReturnT.SUCCESS("保存成功");
        }

## 解决方案 ##

public class EhCacheUtil { 
    
        public static final String CACHE_NAME_CERT_COMPANY="cache-certCompany";
        public static final String CACHE_NAME_CERT_COMPANY_LIST="cache-certCompanyList";
        public static final String CACHE_KEY_CERT_COMPANY_OBJ="#certCompany.certId";
        //zhengkai.blog.csdn.net 新增以解决Null key returned for cache operation问题
        public static final String CACHE_KEY_CERT_COMPANY_OBJ_NOTNULL="#certCompany.certId !=null ";
        public static final String CACHE_KEY_CERT_COMPANY_ID="#id";
    	//省略其他
    }

/** * 新增或编辑 */
        @PostMapping("/save")
        @CacheEvict(value = EhCacheUtil.CACHE_NAME_CERT_COMPANY, key = EhCacheUtil.CACHE_KEY_CERT_COMPANY_OBJ,condition = EhCacheUtil.CACHE_KEY_CERT_COMPANY_OBJ_NOTNULL)
        public Object save(@RequestBody CertCompany certCompany){ 
            //省略业务逻辑
        }