/*
* JBoss, Home of Professional Open Source
* Copyright 2005, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.aop.metadata;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import org.jboss.aop.joinpoint.Invocation;
import org.jboss.aop.util.MarshalledValue;
import org.jboss.aop.util.PayloadKey;
/**
* Contains all the metadata associated with an
* {@link org.jboss.aop.joinpoint.Invocation} instance.
*
* @author <a href="mailto:bill@jboss.org">Bill Burke</a>
* @version $Revision: 68585 $
*/
public class SimpleMetaData implements MetaDataResolver, java.io.Externalizable
{
static final long serialVersionUID = -3873275588469743345L;
/**
* Contains all the metadata entries.
*/
protected HashMap<Object, HashMap<Object, MetaDataValue>> metaData =
new HashMap<Object, HashMap<Object, MetaDataValue>>();
/**
* Contains the value of a metadata attribute.
*/
public class MetaDataValue implements java.io.Serializable
{
static final long serialVersionUID = -8024138149680591337L;
public final PayloadKey type;
public Object value;
/**
* Constructs a metada data entry with the initial value {@code value}.
*
* @param type payload type
* @param value the initial value of this entry
*/
public MetaDataValue(PayloadKey type, Object value)
{
this.type = type;
this.value = value;
}
/**
* Returns the value of this entry.
*
* @return the value of this metadata entry.
* @throws IOException may be thrown during unmarshalling proccess
* (only if payload key type is
* {@link PayloadKey#MARSHALLED})
* @throws ClassNotFoundException may be thrown during unmarshalling proccess
* (only if payload key type is
* {@link PayloadKey#MARSHALLED})
*/
public Object get() throws IOException, ClassNotFoundException
{
if (value instanceof MarshalledValue)
{
value = ((MarshalledValue) value).get();
}
return value;
}
@Override
public String toString()
{
StringBuffer sb = new StringBuffer(100);
sb.append("[");
sb.append("type=").append(type);
sb.append("value=").append(value);
sb.append("]");
return sb.toString();
}
}
/**
* Returns the number of items contained in this simple metadata instance.
*
* @return the number of items contained in this simple metadata instance.
*/
public synchronized int size()
{
return metaData.size();
}
/**
* Returns the tags that identify the metadata elements contained in this
* instance.
*
* @return a set containing all tags of the metadata elements contained in this
* instance.
*/
public synchronized HashSet<Object> tags()
{
return new HashSet<Object>(metaData.keySet());
}
/**
* Returns the metadata tagged with {@code name}.
*
* @param name tag of the queried metadata
* @return a map containing all the metadata tagged with {@code name}
*/
public synchronized HashMap tag(String name)
{
HashMap map = (HashMap) metaData.get(name);
if (map == null) return null;
return (HashMap) map.clone();
}
/**
* Indicates whether this instance contains metadata tagged with {@code name}.
*
* @param name tag of the queried metadata
* @return {@code true} only if there is metadata tagged with {@code name} in this
* simple metadata instance
*/
public synchronized boolean hasTag(String name)
{
return metaData.get(name) != null;
}
/**
* Tags metadata to structure. Use for tags with no attributes (i.e.
* @Singleton, etc...)
*
* @param tag the tag that represents the no-atribute metadata to be added
*/
public void tag(Object tag)
{
addMetaData(tag, EMPTY_TAG, new Object(), PayloadKey.TRANSIENT);
}
/**
* Adds a metadata attribute/value pair to this instance.
*
* @param tag identifies the metadata attribute to be added
* @param attr the name of an attribute
* @param value the value of {@code attr} attribute
*/
public void addMetaData(Object tag, Object attr, Object value)
{
addMetaData(tag, attr, value, PayloadKey.MARSHALLED);
}
/**
* Adds a metadata attribute/value pair to this instance.
*
* @param tag identifies the metadata attribute to be added
* @param attr the name of an attribute
* @param value the value of {@code attr} attribute
* @param type the payload type
*/
public synchronized void addMetaData(Object tag, Object attr, Object value, PayloadKey type)
{
HashMap<Object, MetaDataValue> groupData = metaData.get(tag);
if (groupData == null)
{
groupData = new HashMap<Object, MetaDataValue>();
metaData.put(tag, groupData);
}
MetaDataValue val = new MetaDataValue(type, value);
groupData.put(attr, val);
}
/**
* Returns the value of a metadata attribute.
*
* @param tag identifies the metadata attribute to be retrieved
* @param attr the name of an attribute
* @return the value of {@code attr} attribute
*/
public synchronized Object getMetaData(Object tag, Object attr)
{
try
{
HashMap<Object, MetaDataValue> groupData = metaData.get(tag);
if (groupData == null) return null;
MetaDataValue val = groupData.get(attr);
if (val == null) return null;
return val.get();
}
catch (IOException ioex)
{
throw new RuntimeException("failed on MarshalledValue", ioex);
}
catch (ClassNotFoundException ex)
{
throw new RuntimeException("failed on MarshalledValue", ex);
}
}
/**
* Removes the metadata attribute from this instance.
*
* @param tag identifies the metadata attribute to be removed
* @param attr name of the attribute to be removed
*/
public synchronized void removeMetaData(Object tag, Object attr)
{
HashMap groupData = (HashMap) metaData.get(tag);
if (groupData != null)
{
groupData.remove(attr);
}
}
/**
* Removes all attributes identified by the tag {@code group}.
*
* @param group identifies the attributes to be removed
*/
public synchronized void removeGroupData(Object group)
{
metaData.remove(group);
}
/**
* Erases all the metadata contained in this instance.
*
*/
public synchronized void clear()
{
metaData.clear();
}
/**
* Merges incoming data.
* If there is a crash in tags and attributes names, incoming data will override
* the existing data.
*
* @param data incoming that that should be merged to this instance.
*/
public synchronized void mergeIn(SimpleMetaData data)
{
Iterator it = data.metaData.keySet().iterator();
while (it.hasNext())
{
Object tag = it.next();
HashMap<Object, MetaDataValue> attrs = data.metaData.get(tag);
HashMap<Object, MetaDataValue> map = metaData.get(tag);
if (map == null)
{
map = new HashMap<Object, MetaDataValue>();
this.metaData.put(tag, map);
}
map.putAll(attrs);
}
}
public synchronized Object resolve(Invocation invocation, Object tag, Object attr)
{
return getMetaData(tag, attr);
}
public SimpleMetaData getAllMetaData(Invocation invocation)
{
return this;
}
public void writeExternal(ObjectOutput out) throws IOException
{
//System.out.println("******** marshalling metadata");
Iterator<Object> it = metaData.keySet().iterator();
while (it.hasNext())
{
Object group = it.next();
HashMap map = (HashMap) metaData.get(group);
//System.out.println("******** marshalling group " + group + " size = " + map.size());
if (map != null && map.size() > 0)
{
boolean groupWritten = false;
Iterator attrs = map.keySet().iterator();
while (attrs.hasNext())
{
Object attr = attrs.next();
//System.out.println("******** marshalling attr: " + group + "." + attr);
MetaDataValue value = (MetaDataValue) map.get(attr);
if (value.type == PayloadKey.TRANSIENT) continue;
if (!groupWritten)
{
groupWritten = true;
out.writeObject(group);
}
out.writeObject(attr);
if (value.type == PayloadKey.AS_IS)
{
out.writeObject(value.value);
}
else
{
out.writeObject(new MarshalledValue(value.value));
}
}
if (groupWritten) out.writeObject(null); // placeholder for end of attributes
}
}
out.writeObject(null); // place holder for end of marshall
}
/**
* {@inheritDoc}
*/
public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException
{
//System.out.println("******** unmarshalling metadata");
metaData = new HashMap<Object, HashMap<Object, MetaDataValue>>();
Object group;
while ((group = in.readObject()) != null)
{
//System.out.println("******** unmarshalling group: " + group);
HashMap<Object, MetaDataValue> map = new HashMap<Object, MetaDataValue>();
metaData.put(group, map);
Object attr;
while ((attr = in.readObject()) != null)
{
//System.out.println("******** unmarshalling attr: " + group + "." + attr);
Object obj = in.readObject();
if (obj instanceof MarshalledValue)
{
map.put(attr, new MetaDataValue(PayloadKey.MARSHALLED, obj));
}
else
{
map.put(attr, new MetaDataValue(PayloadKey.AS_IS, obj));
}
}
}
}
public String toString()
{
StringBuffer sb = new StringBuffer(100);
sb.append("[");
sb.append("metaData=").append(metaData);
sb.append("]");
return sb.toString();
}
}