Author: cbrisson
Date: Thu Apr 18 15:07:50 2019
New Revision: 1857757
URL: http://svn.apache.org/viewvc?rev=1857757&view=rev
Log:
[tools/model] Initial import: Velocity context wrappers for all model objects
Added:
velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/ActiveInstanceReference.java
velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/EntityReference.java
velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/InstanceReference.java
velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/ModelTool.java
Added:
velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/ActiveInstanceReference.java
URL:
http://svn.apache.org/viewvc/velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/ActiveInstanceReference.java?rev=1857757&view=auto
==============================================================================
---
velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/ActiveInstanceReference.java
(added)
+++
velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/ActiveInstanceReference.java
Thu Apr 18 15:07:50 2019
@@ -0,0 +1,67 @@
+package org.apache.velocity.tools.model;
+
+import java.io.Serializable;
+import java.util.Map;
+
+public class ActiveInstanceReference extends InstanceReference
+{
+ public ActiveInstanceReference(Instance instance)
+ {
+ super(instance);
+ }
+
+ @Override
+ public Serializable put(String key, Serializable value)
+ {
+ return super.putImpl(key, value);
+ }
+
+ @Override
+ public Serializable remove(Object key)
+ {
+ return super.removeImpl(key);
+ }
+
+ @Override
+ public void putAll(Map<? extends String, ? extends Serializable> m)
+ {
+ super.putAllImpl(m);
+ }
+
+ @Override
+ public void clear()
+ {
+ super.clearImpl();
+ }
+
+ @Override
+ public int perform(String name, Map params)
+ {
+ return super.performImpl(name, params);
+ }
+
+ @Override
+ public int perform(String name, Serializable... params)
+ {
+ return super.performImpl(name, params);
+ }
+
+ @Override
+ public boolean delete()
+ {
+ return super.deleteImpl();
+ }
+
+ @Override
+ public boolean insert()
+ {
+ return super.insertImpl();
+ }
+
+ @Override
+ public boolean update()
+ {
+ return super.updateImpl();
+ }
+
+}
Added:
velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/EntityReference.java
URL:
http://svn.apache.org/viewvc/velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/EntityReference.java?rev=1857757&view=auto
==============================================================================
---
velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/EntityReference.java
(added)
+++
velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/EntityReference.java
Thu Apr 18 15:07:50 2019
@@ -0,0 +1,308 @@
+package org.apache.velocity.tools.model;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import java.io.Serializable;
+import java.sql.SQLException;
+import java.util.Iterator;
+import java.util.Map;
+
+public class EntityReference
+{
+ public EntityReference(Entity entity)
+ {
+ this.entity = entity;
+ }
+
+ protected Entity getEntity()
+ {
+ return entity;
+ }
+
+ public Iterator<InstanceReference> iterator()
+ {
+ try
+ {
+ return new ModelTool.InstanceReferenceIterator(entity.iterate());
+ }
+ catch (SQLException sqle)
+ {
+ entity.getLogger().error("cannot iterate on instances of " +
entity.getName(), sqle);
+ return null;
+ }
+ }
+
+ public long getCount()
+ {
+ try
+ {
+ return entity.getCount();
+ }
+ catch (SQLException sqle)
+ {
+ entity.getLogger().error("could not get {} count",
entity.getName(), sqle);
+ return 0;
+ }
+ }
+
+ protected InstanceReference createInstanceReference(Instance instance)
+ {
+ switch (getEntity().getModel().getWriteAccess())
+ {
+ case NONE:
+ case JAVA:
+ return new InstanceReference(instance);
+ case VTL:
+ return new ActiveInstanceReference(instance);
+ default:
+ getEntity().getModel().getLogger().error("unhandled
write-access enum: {}", getEntity().getModel().getWriteAccess());
+ return null;
+ }
+ }
+
+ public InstanceReference fetch(Serializable... key) throws SQLException
+ {
+ try
+ {
+ Instance instance = entity.fetch(key);
+ return instance == null ? null : new InstanceReference(instance);
+ }
+ catch (SQLException sqle)
+ {
+ entity.getLogger().error("could not fetch instance of {}",
entity.getName(), sqle);
+ return null;
+ }
+ }
+
+ public Object get(String key)
+ {
+ try
+ {
+ Attribute attribute = entity.getAttribute(key);
+ if (attribute != null)
+ {
+ if (attribute instanceof ScalarAttribute)
+ {
+ return ((ScalarAttribute)attribute).evaluate();
+ }
+ else if (attribute instanceof RowAttribute)
+ {
+ Instance instance = ((RowAttribute)attribute).retrieve();
+ return instance == null ? null : new
InstanceReference(instance);
+ }
+ else if (attribute instanceof RowsetAttribute)
+ {
+ return new
ModelTool.InstanceReferenceIterator(((RowsetAttribute)attribute).query());
+ }
+ }
+ return null;
+ }
+ catch (SQLException sqle)
+ {
+ entity.getLogger().error("could not get property {}.{}",
entity.getName(), key, sqle);
+ return null;
+ }
+ }
+
+ public Serializable evaluate(String name, Serializable... params)
+ {
+ try
+ {
+ return entity.evaluate(name, params);
+ }
+ catch (SQLException sqle)
+ {
+ entity.getLogger().error("could not evaluate property {}.{}",
entity.getName(), name, sqle);
+ return null;
+ }
+ }
+
+ public Serializable evaluate(String name, Map params)
+ {
+ try
+ {
+ return entity.evaluate(name, params);
+ }
+ catch (SQLException sqle)
+ {
+ entity.getLogger().error("could not evaluate property {}.{}",
entity.getName(), name, sqle);
+ return null;
+ }
+ }
+
+ public Serializable evaluate(String name)
+ {
+ try
+ {
+ return entity.evaluate(name);
+ }
+ catch (SQLException sqle)
+ {
+ entity.getLogger().error("could not evaluate property {}.{}",
entity.getName(), name, sqle);
+ return null;
+ }
+ }
+
+ public InstanceReference retrieve(String name, Serializable... params)
+ {
+ try
+ {
+ Instance instance = entity.retrieve(name, params);
+ return instance == null ? null : new InstanceReference(instance);
+ }
+ catch (SQLException sqle)
+ {
+ entity.getLogger().error("could not retrieve property {}.{}",
entity.getName(), name, sqle);
+ return null;
+ }
+ }
+
+ public InstanceReference retrieve(String name, Map params)
+ {
+ try
+ {
+ Instance instance = entity.retrieve(name, params);
+ return instance == null ? null : new InstanceReference(instance);
+ }
+ catch (SQLException sqle)
+ {
+ entity.getLogger().error("could not retrieve property {}.{}",
entity.getName(), name, sqle);
+ return null;
+ }
+ }
+
+ public InstanceReference retrieve(String name)
+ {
+ try
+ {
+ Instance instance = entity.retrieve(name);
+ return instance == null ? null : new InstanceReference(instance);
+ }
+ catch (SQLException sqle)
+ {
+ entity.getLogger().error("could not retrieve property {}.{}",
entity.getName(), name, sqle);
+ return null;
+ }
+ }
+
+ public Iterator<InstanceReference> query(String name, Serializable...
params)
+ {
+ try
+ {
+ return new ModelTool.InstanceReferenceIterator(entity.query(name,
params));
+
+ }
+ catch (SQLException sqle)
+ {
+ entity.getLogger().error("could not query property {}.{}",
entity.getName(), name, sqle);
+ return null;
+ }
+ }
+
+ public Iterator<InstanceReference> query(String name, Map params)
+ {
+ try
+ {
+ return new ModelTool.InstanceReferenceIterator(entity.query(name,
params));
+
+ }
+ catch (SQLException sqle)
+ {
+ entity.getLogger().error("could not query property {}.{}",
entity.getName(), name, sqle);
+ return null;
+ }
+ }
+
+ public Iterator<InstanceReference> query(String name)
+ {
+ try
+ {
+ return new ModelTool.InstanceReferenceIterator(entity.query(name));
+
+ }
+ catch (SQLException sqle)
+ {
+ entity.getLogger().error("could not query property {}.{}",
entity.getName(), name, sqle);
+ return null;
+ }
+ }
+
+ public Object get(String key, Map params)
+ {
+ try
+ {
+ Attribute attribute = entity.getAttribute(key);
+ if (attribute != null)
+ {
+ if (attribute instanceof ScalarAttribute)
+ {
+ return ((ScalarAttribute)attribute).evaluate(params);
+ }
+ else if (attribute instanceof RowAttribute)
+ {
+ Instance instance =
((RowAttribute)attribute).retrieve(params);
+ return instance == null ? null : new
InstanceReference(instance);
+ }
+ else if (attribute instanceof RowsetAttribute)
+ {
+ return new
ModelTool.InstanceReferenceIterator(((RowsetAttribute)attribute).query(params));
+ }
+ }
+ return null;
+ }
+ catch (SQLException sqle)
+ {
+ entity.getLogger().error("could not get property {}.{}",
entity.getName(), key, sqle);
+ return null;
+ }
+ }
+
+ public Object get(String key, Serializable... params)
+ {
+ try
+ {
+ Attribute attribute = entity.getAttribute(key);
+ if (attribute != null)
+ {
+ if (attribute instanceof ScalarAttribute)
+ {
+ return ((ScalarAttribute)attribute).evaluate(params);
+ }
+ else if (attribute instanceof RowAttribute)
+ {
+ Instance instance =
((RowAttribute)attribute).retrieve(params);
+ return instance == null ? null : new
InstanceReference(instance);
+ }
+ else if (attribute instanceof RowsetAttribute)
+ {
+ return new
ModelTool.InstanceReferenceIterator(((RowsetAttribute)attribute).query(params));
+ }
+ }
+ return null;
+ }
+ catch (SQLException sqle)
+ {
+ entity.getLogger().error("could not get property {}.{}",
entity.getName(), key, sqle);
+ return null;
+ }
+ }
+
+ private Entity entity = null;
+}
Added:
velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/InstanceReference.java
URL:
http://svn.apache.org/viewvc/velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/InstanceReference.java?rev=1857757&view=auto
==============================================================================
---
velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/InstanceReference.java
(added)
+++
velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/InstanceReference.java
Thu Apr 18 15:07:50 2019
@@ -0,0 +1,304 @@
+package org.apache.velocity.tools.model;
+
+import org.apache.velocity.tools.model.util.SlotMap;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.Serializable;
+import java.sql.SQLException;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
+
+public class InstanceReference implements SlotMap
+{
+ protected static Logger logger =
LoggerFactory.getLogger(InstanceReference.class);
+
+ public InstanceReference(Instance instance)
+ {
+ this.instance = instance;
+ }
+
+ private Instance instance;
+
+ @Override
+ public int size()
+ {
+ return instance.size();
+ }
+
+ @Override
+ public boolean isEmpty()
+ {
+ return instance.isEmpty();
+ }
+
+ @Override
+ public boolean containsKey(Object key)
+ {
+ return instance.containsKey(key);
+ }
+
+ @Override
+ public boolean containsValue(Object value)
+ {
+ return instance.containsValue(value);
+ }
+
+ @Override
+ public Serializable get(Object key)
+ {
+ return instance.get(key);
+ }
+
+ @Override
+ public Serializable put(String key, Serializable value)
+ {
+ logger.error("cannot change read-only instance");
+ return null;
+ }
+
+ protected Serializable putImpl(String key, Serializable value)
+ {
+ return instance.put(key, value);
+ }
+
+ @Override
+ public Serializable remove(Object key)
+ {
+ logger.error("cannot change read-only instance");
+ return null;
+ }
+
+ protected Serializable removeImpl(Object key)
+ {
+ return instance.remove(key);
+ }
+
+ @Override
+ public void putAll(Map<? extends String, ? extends Serializable> m)
+ {
+ logger.error("cannot change read-only instance");
+ }
+
+ public void putAllImpl(Map<? extends String, ? extends Serializable> m)
+ {
+ instance.putAll(m);
+ }
+
+ @Override
+ public void clear()
+ {
+ logger.error("cannot change read-only instance");
+ }
+
+ public void clearImpl()
+ {
+ instance.clear();
+ }
+
+ @Override
+ public Set<String> keySet()
+ {
+ return instance.keySet();
+ }
+
+ @Override
+ public Collection<Serializable> values()
+ {
+ return instance.values();
+ }
+
+ @Override
+ public Set<Entry<String, Serializable>> entrySet()
+ {
+ return instance.entrySet();
+ }
+
+ public Serializable evaluate(String name, Map params)
+ {
+ try
+ {
+ return instance.evaluate(name, params);
+ }
+ catch (SQLException sqle)
+ {
+ logger.error("could not evaluate instance property {}.{}",
instance.getEntity().getName(), name, sqle);
+ return null;
+ }
+ }
+
+ public Serializable evaluate(String name, Serializable... params)
+ {
+ try
+ {
+ return instance.evaluate(name, params);
+ }
+ catch (SQLException sqle)
+ {
+ logger.error("could not evaluate instance property {}.{}",
instance.getEntity().getName(), name, sqle);
+ return null;
+ }
+ }
+
+ public InstanceReference retrieve(String name, Map params)
+ {
+ try
+ {
+ Instance inst = instance.retrieve(name, params);
+ return inst == null ? null : new InstanceReference(inst);
+ }
+ catch (SQLException sqle)
+ {
+ logger.error("could not retrieve instance property {}.{}",
instance.getEntity().getName(), name, sqle);
+ return null;
+ }
+ }
+
+ public InstanceReference retrieve(String name, Serializable... params)
+ {
+ try
+ {
+ Instance inst = instance.retrieve(name, params);
+ return inst == null ? null : new InstanceReference(inst);
+ }
+ catch (SQLException sqle)
+ {
+ logger.error("could not retrieve instance property {}.{}",
instance.getEntity().getName(), name, sqle);
+ return null;
+ }
+ }
+
+ public Iterator<InstanceReference> query(String name, Map params)
+ {
+ try
+ {
+ return new
ModelTool.InstanceReferenceIterator(instance.query(name, params));
+ }
+ catch (SQLException sqle)
+ {
+ logger.error("could not query instance property {}.{}",
instance.getEntity().getName(), name, sqle);
+ return null;
+ }
+ }
+
+ public Iterator<InstanceReference> query(String name, Serializable...
params)
+ {
+ try
+ {
+ return new
ModelTool.InstanceReferenceIterator(instance.query(name, params));
+ }
+ catch (SQLException sqle)
+ {
+ logger.error("could not query instance property {}.{}",
instance.getEntity().getName(), name, sqle);
+ return null;
+ }
+ }
+
+ public int perform(String name, Map params)
+ {
+ logger.error("instance is read-only");
+ return 0;
+ }
+
+ protected int performImpl(String name, Map params)
+ {
+ try
+ {
+ return instance.perform(name, params);
+ }
+ catch (SQLException sqle)
+ {
+ logger.error("could not perform instance action {}.{}",
instance.getEntity().getName(), name, sqle);
+ return 0;
+ }
+
+ }
+
+ public int perform(String name, Serializable... params)
+ {
+ logger.error("instance is read-only");
+ return 0;
+ }
+
+ protected int performImpl(String name, Serializable... params)
+ {
+ try
+ {
+ return instance.perform(name, params);
+ }
+ catch (SQLException sqle)
+ {
+ logger.error("could not perform instance action {}.{}",
instance.getEntity().getName(), name, sqle);
+ return 0;
+ }
+ }
+
+ protected Instance getInstance()
+ {
+ return instance;
+ }
+
+ public boolean delete()
+ {
+ logger.error("cannot delete read-only instance");
+ return false;
+ }
+
+ protected boolean deleteImpl()
+ {
+ try
+ {
+ instance.delete();
+ return true;
+ }
+ catch (SQLException sqle)
+ {
+ logger.error("could not delete instance", sqle);
+ return false;
+ }
+ }
+
+ public boolean insert()
+ {
+ logger.error("cannot insert read-only instance");
+ return false;
+ }
+
+ protected boolean insertImpl()
+ {
+ try
+ {
+ instance.insert();
+ return true;
+ }
+ catch (SQLException sqle)
+ {
+ logger.error("could not insert instance", sqle);
+ return false;
+ }
+ }
+
+ public boolean update()
+ {
+ logger.error("cannot update read-only instance");
+ return false;
+ }
+
+ protected boolean updateImpl()
+ {
+ try
+ {
+ instance.update();
+ return true;
+ }
+ catch (SQLException sqle)
+ {
+ logger.error("could not update instance", sqle);
+ return false;
+ }
+ }
+
+
+}
Added:
velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/ModelTool.java
URL:
http://svn.apache.org/viewvc/velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/ModelTool.java?rev=1857757&view=auto
==============================================================================
---
velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/ModelTool.java
(added)
+++
velocity/tools/branches/model/velocity-tools-model/src/main/java/org/apache/velocity/tools/model/ModelTool.java
Thu Apr 18 15:07:50 2019
@@ -0,0 +1,263 @@
+package org.apache.velocity.tools.model;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import org.apache.velocity.tools.Scope;
+import org.apache.velocity.tools.config.DefaultKey;
+import org.apache.velocity.tools.config.ValidScope;
+import org.apache.velocity.tools.generic.SafeConfig;
+import org.apache.velocity.tools.generic.ValueParser;
+import org.apache.velocity.tools.model.config.ConfigHelper;
+import org.apache.velocity.tools.model.config.Constants;
+
+import java.io.Serializable;
+import java.sql.SQLException;
+import java.util.Iterator;
+import java.util.Map;
+
+/**
+ * <p>ModelTool</p>
+ *
+ * @author Claude Brisson
+ * @version $Revision: $
+ * @since VelocityTools 3.1
+ */
+
+@ValidScope(Scope.APPLICATION)
+@DefaultKey("model")
+public class ModelTool extends SafeConfig implements Constants
+{
+ /**
+ * Configuration entry point. Can only be called once.
+ * @param params configuration values map
+ */
+ public void configure(Map<String, Object> params)
+ {
+ String loggerName = new
ConfigHelper(params).getString(MODEL_LOGGER_NAME);
+ if (loggerName != null)
+ {
+ params.put(SafeConfig.LOGGER_NAME_KEY, loggerName);
+ }
+ super.configure(params);
+ }
+
+ @Override
+ protected void configure(ValueParser params)
+ {
+ model = createModel();
+
+ // handles default and global configuration ;
+ // all those values can be changed during initialization
+ // when model path is read
+ model.configure(params);
+ String key = params.getString("key");
+ if (key == null || key.length() == 0)
+ {
+ key = "default";
+ }
+ model.initialize(key, model.getDefinition());
+ canWrite = model.getWriteAccess() == Model.WriteAccess.VTL;
+ }
+
+ protected Model createModel()
+ {
+ return new Model();
+ }
+
+ protected Model getModel()
+ {
+ return model;
+ }
+
+ public Serializable evaluate(String name, Serializable... params)
+ {
+ try
+ {
+ return getModel().evaluate(name, params);
+ }
+ catch (SQLException sqle)
+ {
+ getLog().error("could not evaluate property {}", name, sqle);
+ return null;
+ }
+ }
+
+ public Serializable evaluate(String name, Map params)
+ {
+ try
+ {
+ return getModel().evaluate(name, params);
+ }
+ catch (SQLException sqle)
+ {
+ getLog().error("could not evaluate property {}", name, sqle);
+ return null;
+ }
+ }
+
+ public InstanceReference retrieve(String name, Serializable... params)
+ {
+ try
+ {
+ Instance instance = getModel().retrieve(name, params);
+ return instance == null ? null : new InstanceReference(instance);
+ }
+ catch (SQLException sqle)
+ {
+ getLog().error("could not retrieve property {}", name, sqle);
+ return null;
+ }
+ }
+
+ public InstanceReference retrieve(String name, Map params)
+ {
+ try
+ {
+ Instance instance = getModel().retrieve(name, params);
+ return instance == null ? null : new InstanceReference(instance);
+ }
+ catch (SQLException sqle)
+ {
+ getLog().error("could not retrieve property {}", name, sqle);
+ return null;
+ }
+ }
+
+ public Iterator<InstanceReference> query(String name, Serializable...
params)
+ {
+ try
+ {
+ return new InstanceReferenceIterator(getModel().query(name,
params));
+ }
+ catch (SQLException sqle)
+ {
+ getLog().error("could not iterate property {}", name, sqle);
+ return null;
+ }
+ }
+
+ public Iterator<InstanceReference> query(String name, Map params)
+ {
+ try
+ {
+ return new InstanceReferenceIterator(getModel().query(name,
params));
+ }
+ catch (SQLException sqle)
+ {
+ getLog().error("could not iterate property {}", name, sqle);
+ return null;
+ }
+ }
+
+ public int perform(String name, Serializable... params)
+ {
+ try
+ {
+ if (!canWrite)
+ {
+ throw new SQLException("instance is read-only");
+ }
+ return getModel().perform(name, params);
+
+ }
+ catch (SQLException sqle)
+ {
+ getLog().error("could not perform action {}", name, sqle);
+ return 0;
+ }
+ }
+
+ public int perform(String name, Map params)
+ {
+ try
+ {
+ if (!canWrite)
+ {
+ throw new SQLException("instance is read-only");
+ }
+ return getModel().perform(name, params);
+
+ }
+ catch (SQLException sqle)
+ {
+ getLog().error("could not perform action {}", name, sqle);
+ return 0;
+ }
+ }
+
+ public Object get(String key)
+ {
+ try
+ {
+ Attribute attribute = model.getAttribute(key);
+ if (attribute != null)
+ {
+ if (attribute instanceof ScalarAttribute)
+ {
+ return ((ScalarAttribute)attribute).evaluate();
+ }
+ else if (attribute instanceof RowAttribute)
+ {
+ Instance instance = ((RowAttribute)attribute).retrieve();
+ return instance == null ? null : new
InstanceReference(instance);
+ }
+ else if (attribute instanceof RowsetAttribute)
+ {
+ return new
InstanceReferenceIterator(((RowsetAttribute)attribute).query());
+ }
+ }
+ Entity entity = model.getEntity(key);
+ if (entity != null)
+ {
+ return new EntityReference(entity);
+ }
+ return null;
+ }
+ catch (SQLException sqle)
+ {
+ getLog().error("could not get property {}", key, sqle);
+ return null;
+ }
+ }
+
+ private Model model = null;
+ private boolean canWrite = false;
+
+ public static class InstanceReferenceIterator implements
Iterator<InstanceReference>
+ {
+ public InstanceReferenceIterator(Iterator<Instance> iterator)
+ {
+ this.iterator = iterator;
+ }
+
+ @Override
+ public boolean hasNext()
+ {
+ return iterator.hasNext();
+ }
+
+ @Override
+ public InstanceReference next()
+ {
+ return new InstanceReference(iterator.next());
+ }
+ private Iterator<Instance> iterator;
+ }
+}
