设置Neo4j的缓存

Question

我使用的Neo4j 1.9.4用于一个项目，我碰到一个奇怪的现象：

我有这样的一段代码，效果很好。我已经设置了一个常青藤文件的类路径，一切都很好。

public static void main(String[] args) { 
    // the cache providers 
    ArrayList<CacheProvider> cacheList = new ArrayList<CacheProvider>(); 
    System.out.println("Creating db configuration"); 
    cacheList.add(new SoftCacheProvider()); 

    // the kernel extensions 
    LuceneKernelExtensionFactory lucene = new LuceneKernelExtensionFactory(); 
    List<KernelExtensionFactory<?>> extensions = new 
     ArrayList<KernelExtensionFactory<?>>(); 
    extensions.add(lucene); 

    // the database setup 
    GraphDatabaseFactory gdbf = new GraphDatabaseFactory(); 
    gdbf.setKernelExtensions(extensions); 
    gdbf.setCacheProviders(cacheList); 
    GraphDatabaseService db = gdbf.newEmbeddedDatabase("/tmp/test"); 
} 

问题是，当我试图改变cacheList.add(new SoftCacheProvider())为​​我得到以下错误：

java.lang.IllegalArgumentException: No provider for cache type 'soft'. Cache providers are loaded using java service loading where they register themselves in resource (plain-text) files found on the class path under META-INF/services/org.neo4j.kernel.impl.cache.CacheProvider. This missing provider may have been caused by either such a missing registration, or by the lack of the provider class itself. 
    at org.neo4j.kernel.InternalAbstractGraphDatabase.create(InternalAbstractGraphDatabase.java:356) 
    at org.neo4j.kernel.InternalAbstractGraphDatabase.run(InternalAbstractGraphDatabase.java:252) 
    at org.neo4j.kernel.EmbeddedGraphDatabase.<init>(EmbeddedGraphDatabase.java:106) 
    at org.neo4j.graphdb.factory.GraphDatabaseFactory$1.newDatabase(GraphDatabaseFactory.java:88) 
    at org.neo4j.graphdb.factory.GraphDatabaseBuilder.newGraphDatabase(GraphDatabaseBuilder.java:207) 
    at org.neo4j.graphdb.factory.GraphDatabaseFactory.newEmbeddedDatabase(GraphDatabaseFactory.java:69) 
    at ttt.App.main(App.java:34) 

也有同样的错误，如果我尝试使用NoChacheProvider或StrongCacheProvider。

我试图添加文件META-INF/services/org.neo4j.kernel.impl.cache.CacheProvider以下内容，但它不会改变任何东西。

org.neo4j.kernel.impl.cache.WeakCacheProvider 
org.neo4j.kernel.impl.cache.SoftCacheProvider 
org.neo4j.kernel.impl.cache.NoCacheProvider 
org.neo4j.kernel.impl.cache.StrongCacheProvider 

你知道发生了什么吗？我不明白为什么只有一个缓存提供程序类型正在工作。

请注意，我必须使用Neo4j 1.9.4，我无法更改它。

编辑：我的项目是没有任何其他的依赖条件

EDIT2一个基本的Eclipse插件项目：一个其他有趣的一点是，如果我尝试配置了Map<String,String>我得到同样的错误的数据库，甚至<"cache_type","soft"> 。

public static void main(String[] args) { 
    Map<String,String> config = new HashMap<String,String>(); 
    config.put("cache_type", "soft"); 
    GraphDatabaseService db = null; 
    db = new EmbeddedGraphDatabase("/tmp/test", config, Collections.EMPTY_LIST, Collections.EMPTY_LIST, Collections.EMPTY_LIST, Collections.EMPTY_LIST); 
} 

java.lang.IllegalArgumentException: No provider for cache type 'soft'. Cache providers are loaded using java service loading where they register themselves in resource (plain-text) files found on the class path under META-INF/services/org.neo4j.kernel.impl.cache.CacheProvider. This missing provider may have been caused by either such a missing registration, or by the lack of the provider class itself. 
    at org.neo4j.kernel.InternalAbstractGraphDatabase.create(InternalAbstractGraphDatabase.java:356) 
    at org.neo4j.kernel.InternalAbstractGraphDatabase.run(InternalAbstractGraphDatabase.java:252) 
    at org.neo4j.kernel.EmbeddedGraphDatabase.<init>(EmbeddedGraphDatabase.java:106) 
    at ttt.App.main(App.java:36) 

Answer 1

什么尝试直接在配置中指定，像这样：

GraphDatabaseService db = gdbf.newEmbeddedDatabaseBuilder('path/to/db').setConfig(GraphDatabaseSettings.cache_type, WeakCacheProvider.NAME).newGraphDatabase() 

当然，我还没有在1.9.4试过，但是，也许这是值得一试。