有没有办法让 eclipselink/JPA 使用 redis 来保存和检索持久单元级缓存？

Question

我正在设置一个集群环境，并且希望在整个集群节点中复制 JPA 的二级缓存。我使用 eclipselink 作为 JPA 提供程序，使用 redis 进行缓存管理。

Answer 1

没有官方或社区项目支持它。

但是，您可以实现自己的CacheInterceptor。

例如。

import org.eclipse.persistence.descriptors.ClassDescriptor;

import org.eclipse.persistence.internal.identitymaps.CacheKey;

import org.eclipse.persistence.internal.identitymaps.IdentityMap;

import org.eclipse.persistence.internal.sessions.AbstractSession;

import org.eclipse.persistence.sessions.interceptors.CacheInterceptor;

import org.eclipse.persistence.sessions.interceptors.CacheKeyInterceptor;

import java.util.Map;

public class MyRedisCacheInterceptor extends CacheInterceptor {

    private final MyCacheProvider cacheSupport;

    private final String cacheName;

    public DefaultCacheInterceptor(IdentityMap targetIdentityMap, AbstractSession interceptedSession,

                                   String cacheName, DefaultCacheSupport cacheSupport) {

        super(targetIdentityMap, interceptedSession);

        this.cacheSupport = cacheSupport;

        this.cacheName = cacheName;

    }

    @Override

    public Object clone() {

        return null;

    }

    @Override

    protected CacheKeyInterceptor createCacheKeyInterceptor(CacheKey wrappedCacheKey) {

        final long longKey = (long) wrappedCacheKey.getKey();

        CacheKeyInterceptor newKey = new CacheKeyInterceptor(wrappedCacheKey) {

            @Override

            public Object getObject() {

                return cacheSupport.getOrCreateCache(cacheName).get(longKey);

            }

            @Override

            public void setObject(Object object) {

                cacheSupport.getOrCreateCache(cacheName).put(longKey, object);

            }

        };

        return newKey;

    }

    @Override

    public boolean containsKey(Object primaryKey) {

        return cacheSupport.getOrCreateCache(cacheName).containsKey(primaryKey);

    }

    @Override

    public Map<Object, Object> getAllFromIdentityMapWithEntityPK(Object[] pkList, ClassDescriptor descriptor, AbstractSession session) {

        return null;

    }

    @Override

    public Map<Object, CacheKey> getAllCacheKeysFromIdentityMapWithEntityPK(Object[] pkList, ClassDescriptor descriptor, AbstractSession session) {

        return null;

    }

    @Override

    public void release() {

    }

}