Java OperationStatus.NOTFOUND屬性代碼示例

public Set<String> getChildren(String parentHash)
{
    try
    {
        // Instantiate class catalog
        StoredClassCatalog neighborCatalog = new StoredClassCatalog(neighborDatabase);
        // Create the binding
        EntryBinding<Neighbors> neighborBinding = new SerialBinding<>(neighborCatalog, Neighbors.class);
        // Create DatabaseEntry for the key
        DatabaseEntry key = new DatabaseEntry(parentHash.getBytes("UTF-8"));
        // Create the DatabaseEntry for the data.
        DatabaseEntry data = new DatabaseEntry();
        // query database to get the key-value
        OperationStatus operationStatus = scaffoldDatabase.get(null, key, data, LockMode.DEFAULT);
        if(operationStatus != OperationStatus.NOTFOUND)
        {
            Neighbors neighbors = neighborBinding.entryToObject(data);
            return neighbors.children;
        }
    }
    catch (UnsupportedEncodingException ex)
    {
        Logger.getLogger(Scaffold.class.getName()).log(Level.SEVERE, "Scaffold entry insertion error!", ex);
    }
    return null;
}
 

public Set<String> getParents(String childHash)
{
    try
    {
        // Instantiate class catalog
        StoredClassCatalog neighborCatalog = new StoredClassCatalog(neighborDatabase);
        // Create the binding
        EntryBinding<Neighbors> neighborBinding = new SerialBinding<>(neighborCatalog, Neighbors.class);
        // Create DatabaseEntry for the key
        DatabaseEntry key = new DatabaseEntry(childHash.getBytes("UTF-8"));
        // Create the DatabaseEntry for the data.
        DatabaseEntry data = new DatabaseEntry();
        // query database to get the key-value
        OperationStatus operationStatus = scaffoldDatabase.get(null, key, data, LockMode.DEFAULT);
        if(operationStatus != OperationStatus.NOTFOUND)
        {
            Neighbors neighbors = neighborBinding.entryToObject(data);
            return neighbors.parents;
        }
    }
    catch (UnsupportedEncodingException ex)
    {
        Logger.getLogger(Scaffold.class.getName()).log(Level.SEVERE, "Scaffold entry insertion error!", ex);
    }
    return null;
}
 

@SuppressWarnings("unchecked")
public HGRandomAccessResult<HGPersistentHandle> getIncidenceResultSet(HGPersistentHandle handle)
{
	if (handle == null)
		throw new NullPointerException("HGStore.getIncidenceSet called with a null handle.");

	Cursor cursor = null;
	try
	{
		DatabaseEntry key = new DatabaseEntry(handle.toByteArray());
		DatabaseEntry value = new DatabaseEntry();
		TransactionBJEImpl tx = txn();
		cursor = incidence_db.openCursor(tx.getBJETransaction(), cursorConfig);
		OperationStatus status = cursor.getSearchKey(key, value, LockMode.DEFAULT);
		if (status == OperationStatus.NOTFOUND)
		{
			cursor.close();
			return (HGRandomAccessResult<HGPersistentHandle>) HGSearchResult.EMPTY;
		}
		else
			return new SingleKeyResultSet<HGPersistentHandle>(tx.attachCursor(cursor), key,
					BAtoHandle.getInstance(handleFactory));
	}
	catch (Throwable ex)
	{
		if (cursor != null)
			try
			{
				cursor.close();
			}
			catch (Throwable t)
			{
			}
		throw new HGException("Failed to retrieve incidence set for handle " + handle + ": " + ex.toString(), ex);
	}
}
 

public long getIncidenceSetCardinality(HGPersistentHandle handle)
{
	if (handle == null)
		throw new NullPointerException("HGStore.getIncidenceSetCardinality called with a null handle.");

	Cursor cursor = null;
	try
	{
		DatabaseEntry key = new DatabaseEntry(handle.toByteArray());
		DatabaseEntry value = new DatabaseEntry();
		cursor = incidence_db.openCursor(txn().getBJETransaction(), cursorConfig);
		OperationStatus status = cursor.getSearchKey(key, value, LockMode.DEFAULT);
		if (status == OperationStatus.NOTFOUND)
			return 0;
		else
			return cursor.count();
	}
	catch (Exception ex)
	{
		throw new HGException("Failed to retrieve incidence set for handle " + handle + ": " + ex.toString(), ex);
	}
	finally
	{
		try
		{
			cursor.close();
		}
		catch (Throwable t)
		{
		}
	}
}
 

public Map<String, Set<String>> getLineage(String hash, String direction, int maxDepth)
{
    try
    {
        // Instantiate class catalog
        StoredClassCatalog neighborCatalog = new StoredClassCatalog(neighborDatabase);
        // Create the binding
        EntryBinding<Neighbors> neighborBinding = new SerialBinding<>(neighborCatalog, Neighbors.class);
        // Create DatabaseEntry for the key
        DatabaseEntry key = new DatabaseEntry(hash.getBytes("UTF-8"));
        // Create the DatabaseEntry for the data.
        DatabaseEntry data = new DatabaseEntry();
        // query database to get the key-value
        OperationStatus operationStatus = scaffoldDatabase.get(null, key, data, LockMode.DEFAULT);
        if(operationStatus != OperationStatus.NOTFOUND)
        {
            Set<String> remainingVertices = new HashSet<>();
            Set<String> visitedVertices = new HashSet<>();
            Map<String, Set<String>> lineageMap = new HashMap<>();
            remainingVertices.add(hash);
            int current_depth = 0;
            while(!remainingVertices.isEmpty() && current_depth < maxDepth)
            {
                visitedVertices.addAll(remainingVertices);
                Set<String> currentSet = new HashSet<>();
                for(String current_hash: remainingVertices)
                {
                    Set<String> neighbors = null;
                    if(DIRECTION_ANCESTORS.startsWith(direction.toLowerCase()))
                        neighbors = getParents(current_hash);
                    else if(DIRECTION_DESCENDANTS.startsWith(direction.toLowerCase()))
                        neighbors = getChildren(current_hash);

                    if(neighbors != null)
                    {
                        lineageMap.put(current_hash, neighbors);
                        for(String vertexHash: neighbors)
                        {
                            if(!visitedVertices.contains(vertexHash))
                            {
                                currentSet.addAll(neighbors);
                            }
                        }
                    }
                }
                remainingVertices.clear();
                remainingVertices.addAll(currentSet);
                current_depth++;
            }

            return lineageMap;
        }
    }
    catch(UnsupportedEncodingException ex)
    {
        Logger.getLogger(Scaffold.class.getName()).log(Level.SEVERE, "Scaffold Get Lineage error!", ex);
    }

    return null;
}