db4o到db4o复制不完全复制

Question

我无法使复制在两个db4o数据库之间完全运行。我遵循了很多教程，我的代码似乎与他们一致（显然不是）。输出表明ReplicationSession检测到更改，但不会复制其他数据库中的更改。

private ReflectiveDatabase() 
{ 
    openDb(); 
    providerA = new Db4oEmbeddedReplicationProvider(hostContainer); 
    providerB = new Db4oEmbeddedReplicationProvider(clientContainer); 

    //Start a new ReplicationSession with event for replacing newest object on conflict. 
    replication = Replication.begin(providerA, providerB, 
    new ReplicationEventListener() { 
     @Override 
     public void onReplicate(ReplicationEvent replicationEvent) { 
      if (replicationEvent.isConflict()) { 
       ObjectState stateDesktop = replicationEvent.stateInProviderA(); 
       ObjectState stateMobile = replicationEvent.stateInProviderB(); 

       if (stateDesktop.modificationDate() >= stateMobile.modificationDate()) { 
        replicationEvent.overrideWith(stateDesktop); 
       } else { 
        replicationEvent.overrideWith(stateMobile); 
       } 
      } 
     } 
    }); 
} 

public EmbeddedConfiguration configure() 
{ 
    EmbeddedConfiguration configuration = Db4oEmbedded.newConfiguration(); 
    configuration.file().generateUUIDs(ConfigScope.GLOBALLY); 
    configuration.file().generateCommitTimestamps(true); 
    return configuration; 
} 

public void openDb() 
{ 
    // try to connect to the host 
    if(hostContainer != null) hostContainer.close(); 

    try 
    { 
     hostContainer = Db4oEmbedded.openFile(configure(), "local1.db4o"); 
    } 
    catch (com.db4o.ext.Db4oIOException e) 
    { 
     ... 
    } 

    // try to connect to the client 
    if(clientContainer != null) 
    { 
     clientContainer.close(); 
    } 

    try 
    { 
     clientContainer = Db4oEmbedded.openFile(configure(), "local2.db4o"); 
    } 
    catch (com.db4o.ext.Db4oIOException e) 
    { 
     ... 
    } 
} 

这里是我已经从一个计时器每787-8

public void syncDatabases() 
{   
    // First get the changes of the two replication-partners 
    ObjectSet<Object> changesOnHost = replication.providerA().objectsChangedSinceLastReplication(); 
    ObjectSet<Object> changesOnClient = replication.providerB().objectsChangedSinceLastReplication(); 
    System.out.println("Changes on Server: " + changesOnHost.size()); 
    System.out.println("Changes on Client: " + changesOnClient.size()); 
    // then iterate over both change-sets and replicate it 
    for (Object changedObjectOnClient : changesOnClient) 
    { 
     replication.replicate(changedObjectOnClient); 
    } 
    for (Object changedObjectOnHost : changesOnHost) 
    { 
     replication.replicate(changedObjectOnHost); 
    } 
    replication.commit(); 
} 

public void writeToClient(Object object) 
{ 
    clientContainer.store(object); 
    clientContainer.commit(); 
} 

作品就好了创建并写入到数据库中的新对象运行的实际同步。

如果我从其中一个数据库（如字段更改）写入更改的对象，则运行时的同步方法将会检测到存在更改的对象，并且事实上它是正确的，并且其字段已更改。但是，我没有看到该对象正在其他数据库中复制。其字段与更改的对象字段不同。

难道我只是对db4o的复制能力有一种误解吗？作为第二年，我的联赛有点不合时宜，但如果任何人都可以看到我的错在哪里，我将不胜感激。

Answer 1

我设法让版本8正确复制。我没有完全按照教程做出假设（虽然没有澄清，但仍然是一个假设）。

似乎在同步时实例化ReplicationSession和ReplicationProviders是至关重要的。我改变了我的代码，以便在SyncDatabases（）这些被创建和不保存（我猜垃圾回收照顾他们）。

public void syncDatabases() 
{   
    // First get the changes of the two replication-partners 
    Db4oEmbeddedReplicationProvider providerA = new Db4oEmbeddedReplicationProvider(hostContainer); 
    Db4oEmbeddedReplicationProvider providerB = new Db4oEmbeddedReplicationProvider(clientContainer); 
    ReplicationSession replication = Replication.begin(providerA, providerB); 

    ObjectSet<Object> changesOnHost = replication.providerA().objectsChangedSinceLastReplication(); 
    ObjectSet<Object> changesOnClient = replication.providerB().objectsChangedSinceLastReplication(); 

    // then iterate over both change-sets and replicate it 
    for (Object changedObjectOnClient : changesOnClient) 
    { 
     replication.replicate(changedObjectOnClient); 
    } 
    for (Object changedObjectOnHost : changesOnHost) 
    { 
     replication.replicate(changedObjectOnHost); 
    } 
    replication.commit(); 

    replication.replicateDeletions(Object.class); 
} 

该构造函数只是运行openDb（）来获取objectContainers初始化。