java设置Neo4j缓存

3 月，1 周 Questions & Answers 507

我在一个项目中使用Neo4j 1.9.4，遇到了一个奇怪的行为：

我有一段代码运行良好。我用一个常春藤文件设置了类路径，一切正常

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，当我尝试将cacheList.add(new SoftCacheProvider())更改为cacheList.add(new WeakCacheProvider())时，会出现以下错误：

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)

如果尝试使用NoChacheProvider或StrongCacheProvider，也会出现相同的错误

我试图添加具有以下内容的文件META-INF/services/org.neo4j.kernel.impl.cache.CacheProvider，但它没有改变任何内容

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

你知道发生了什么事吗？我不明白为什么只有一种缓存提供程序类型在工作

请注意，我必须使用Neo4j 1.9.4，我无法更改它

编辑：我的项目是一个基本的eclipse插件项目，没有任何其他依赖项

Edit2：另一个有趣的问题是，如果我试图用Map<String,String>配置数据库，我会得到相同的错误，即使是<"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)

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java设置Neo4j缓存

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