具有@ManyTomany关系ebean缓存问题

Question

当我试图使用ebean缓存系统（带有io.ebean：ebean-redis）读取@ManyTomany关系时，我遇到了一个异常。这是一个springboot应用程序。

我正在使用的版本：

• SpringBootVersion=2.4.3
• MariaDbVersion=2.7.2
• EBeanVersion=12.7.2
• Flywayversion=7.7.0

BaseModel Java类：

@MappedSuperclass
public abstract class BaseModel extends Model {

    @Id
    @GeneratedValue
    private Long id;

    @WhenCreated
    @NotNull
    private Instant createdAt;

    @WhenModified
    @NotNull
    private Instant updatedAt;

    @NotNull
    @SoftDelete
    private Boolean deleted = false;

    protected BaseModel() {
    }

    // here the getters and setters
}

文章Java类：

@Entity
@Table(name = "article")
@Cache
public class DArticle extends BaseModel {

    private static final long serialVersionUID = -7120023327129825322L;

    @NotNull
    @Index
    @Length(20)
    private String code;

    @DbJson
    @NotNull
    private Map<Locale, String> name;

    @NotNull
    private Double unitPrice;

    @ManyToMany(mappedBy = "articles")
    private List<DArticleCategory> articleCategories;

    public DArticle(String code, Map<Locale, String> name, Double unitPrice) {
        super();
        this.code = code;
        this.name = name;
        this.unitPrice = unitPrice;
    }

    // here the getters and setters
}

ArticleCategory Java类：

@Entity
@Table(name = "article_category")
@Cache
public class DArticleCategory extends BaseModel {

    private static final long serialVersionUID = 528512691717594544L;

    @DbJson
    @NotNull
    private Map<Locale, String> name;

    @ManyToMany
    private List<DArticle> articles;

    public DArticleCategory(Map<Locale, String> name) {
        super();
        this.name = name;
    }

    // here the getters and setters

}

SQL（我使用flyway进行迁移）：

create table `article` (
  `id`                            bigint auto_increment not null,
  `created_at`                    datetime(6) not null,
  `updated_at`                    datetime(6) not null,
  `deleted`                       tinyint(1) not null,
  `code`                          varchar(20) not null,
  `name`                          longtext not null,
  `unit_price`                    double not null,
  primary key (`id`),
  index (`code`)
);

create table `article_category` (
  `id`                            bigint auto_increment not null,
  `created_at`                    datetime(6) not null,
  `updated_at`                    datetime(6) not null,
  `deleted`                       tinyint(1) not null,
  `name`                          longtext not null,
  primary key (`id`)
);

我尝试执行的代码：

DArticleCategory c = new DArticleCategory(getTranslatedText("Category 1", "Catégorie 1", null));
c.save();

DArticleCategory cat = articleCategoryRepository.findById(1l);
for (DArticle article : cat.getArticles()) {
    //nothing
}

例外情况：

Caused by: java.lang.RuntimeException: Failed to decode cache data
    at io.ebean.redis.encode.EncodePrefixKey.encode(EncodePrefixKey.java:26)
    at io.ebean.redis.RedisCache.key(RedisCache.java:85)
    at io.ebean.redis.RedisCache.get(RedisCache.java:139)
    at io.ebeaninternal.server.deploy.BeanDescriptorCacheHelp.manyPropGet(BeanDescriptorCacheHelp.java:277)
    at io.ebeaninternal.server.deploy.BeanDescriptorCacheHelp.manyPropLoad(BeanDescriptorCacheHelp.java:297)
    at io.ebeaninternal.server.deploy.BeanDescriptor.cacheManyPropLoad(BeanDescriptor.java:1306)
    at io.ebeaninternal.server.loadcontext.DLoadManyContext$LoadBuffer.loadMany(DLoadManyContext.java:215)
    at io.ebean.common.AbstractBeanCollection.lazyLoadCollection(AbstractBeanCollection.java:101)
    at io.ebean.common.BeanList.init(BeanList.java:139)
    at io.ebean.common.BeanList.iterator(BeanList.java:335)
    at db.migration.dev.V2_0_1__katel_test.migrate(V2_0_1__katel_test.java:200)
    at org.flywaydb.core.internal.resolver.java.JavaMigrationExecutor.executeOnce(JavaMigrationExecutor.java:61)
    ... 59 common frames omitted
Caused by: java.lang.IllegalStateException: Expecting String keys but got type:class java.lang.Long
    at io.ebean.redis.encode.EncodePrefixKey.encode(EncodePrefixKey.java:19)
    ... 70 common frames omitted

它看起来是一个非常简单的代码，但我看不出我错在哪里...

Answer 1

注释@Cacheable仅对允许作为拦截器的公共公开方法可用。但是您可以获得“CacheManager”服务并在代码中使用它来在内部处理私募方法中的缓存（如果需要的话）。但只有解决一些“特殊”问题，通常的方法是注释公开的方法。

此外，如果您只使用启动程序，您使用的只是spring的基本和糟糕的实现，一个简单的内存缓存。

想想你的应用程序将如何工作（单个应用程序、分布式应用程序、缓存的短/长数据量、...)以及添加任何受支持的缓存管理器（如ehCache、Hazelcast、Caffeine等）的依赖项所需的内存消耗...满足您的要求并提高缓存性能。