com.tangosol.util.MapEvent Maven / Gradle / Ivy
Show all versions of coherence Show documentation
/*
* Copyright (c) 2000, 2022, Oracle and/or its affiliates.
*
* Licensed under the Universal Permissive License v 1.0 as shown at
* https://oss.oracle.com/licenses/upl.
*/
package com.tangosol.util;
import com.tangosol.internal.tracing.Span;
import com.tangosol.internal.tracing.TracingHelper;
import com.tangosol.io.ClassLoaderAware;
import com.tangosol.io.pof.PofReader;
import com.tangosol.io.pof.PofWriter;
import com.tangosol.io.pof.PortableObject;
import java.io.IOException;
import java.util.EventListener;
import java.util.EventObject;
import java.util.Map;
import javax.json.bind.annotation.JsonbProperty;
/**
* An event which indicates that the content of a map has changed:
*
* - an entry has been added
*
- an entry has been removed
*
- an entry has been changed
*
* A MapEvent object is sent as an argument to the MapListener interface
* methods. Null values may be provided for the old and the new values.
*
* @param the type of the Map entry key
* @param the type of the Map entry value
*
* @author gg 2002.02.11
*/
public class MapEvent
extends EventObject
implements PortableObject
{
/**
* Default constructor for serialization.
*/
public MapEvent()
{
// We cannot pass a null source to the super class constructor
// but the source is transient and will not have been serialized
// so we pass a dummy source to the constructor and then set it
// to null
super(new Object());
source = null;
}
/**
* Constructs a new MapEvent.
*
* @param map the ObservableMap object that fired the event
* @param nId this event's id, one of {@link #ENTRY_INSERTED},
* {@link #ENTRY_UPDATED} or {@link #ENTRY_DELETED}
* @param oKey the key into the map
* @param oValueOld the old value (for update and delete events)
* @param oValueNew the new value (for insert and update events)
*/
public MapEvent(ObservableMap map, int nId, K oKey, V oValueOld, V oValueNew)
{
super(map);
m_nId = nId;
m_oKey = oKey;
m_oValueOld = oValueOld;
m_oValueNew = oValueNew;
}
/**
* Return an ObservableMap object on which this event has actually
* occurred.
*
* @return an ObservableMap object
*/
public ObservableMap getMap()
{
// IMPORTANT: The return type here must be raw as we transformers
// may have changed the key and value types.
return (ObservableMap) getSource();
}
/**
* Return this event's id. The event id is one of the ENTRY_*
* enumerated constants.
*
* @return an id
*/
public int getId()
{
return m_nId;
}
/**
* Return a key associated with this event.
*
* @return a key
*/
public K getKey()
{
return m_oKey;
}
/**
* Return an old value associated with this event.
*
* The old value represents a value deleted from or updated in a map.
* It is always null for "insert" notifications.
*
* @return an old value
*/
public V getOldValue()
{
return m_oValueOld;
}
/**
* Return a new value associated with this event.
*
* The new value represents a new value inserted into or updated in
* a map. It is always null for "delete" notifications.
*
* @return a new value
*/
public V getNewValue()
{
return m_oValueNew;
}
/**
* Return a Map Entry that represents the state of the Entry before the
* change occurred that generated this event.
*
* @return a Map Entry representing the pre-event state of the Entry
*
* @since Coherence 3.6
*/
public Map.Entry getOldEntry()
{
return new SimpleMapEntry()
{
public K getKey()
{
return MapEvent.this.getKey();
}
public V getValue()
{
return MapEvent.this.getOldValue();
}
public V setValue(V oValue)
{
throw new UnsupportedOperationException();
}
};
}
/**
* Return a Map Entry that represents the state of the Entry after the
* change occurred that generated this event.
*
* @return a Map Entry representing the post-event state of the Entry
*
* @since Coherence 3.6
*/
public Map.Entry getNewEntry()
{
return new SimpleMapEntry()
{
public K getKey()
{
return MapEvent.this.getKey();
}
public V getValue()
{
return MapEvent.this.getNewValue();
}
public V setValue(V oValue)
{
throw new UnsupportedOperationException();
}
};
}
/**
* Determine whether this event is an insert event.
*
* @return {@code true} if this event is an insert event
*/
public boolean isInsert()
{
return m_nId == ENTRY_INSERTED;
}
/**
* Determine whether this event is an update event.
*
* @return {@code true} if this event is an update event
*/
public boolean isUpdate()
{
return m_nId == ENTRY_UPDATED;
}
/**
* Determine whether this event is a delete event.
*
* @return {@code true} if this event is a delete event
*/
public boolean isDelete()
{
return m_nId == ENTRY_DELETED;
}
// ----- PortableObject methods -----------------------------------------
@Override
public void readExternal(PofReader in) throws IOException
{
m_nId = in.readInt(0);
m_oKey = in.readObject(1);
m_oValueOld = in.readObject(2);
m_oValueNew = in.readObject(3);
}
@Override
public void writeExternal(PofWriter out) throws IOException
{
out.writeInt(0, m_nId);
out.writeObject(1, m_oKey);
out.writeObject(2, m_oValueOld);
out.writeObject(3, m_oValueNew);
}
// ----- Object methods -------------------------------------------------
/**
* Return a String representation of this MapEvent object.
*
* @return a String representation of this MapEvent object
*/
public String toString()
{
String sEvt = getClass().getName();
String sSrc = getSource().getClass().getName();
return sEvt.substring(sEvt.lastIndexOf('.') + 1) + '{'
+ sSrc.substring(sSrc.lastIndexOf('.') + 1)
+ getDescription() + '}';
}
// ----- helpers ------------------------------------------------------
/**
* Dispatch this event to the specified listeners collection.
*
* This call is equivalent to
*
* dispatch(listeners, true);
*
*
* @param listeners the listeners collection
*
* @throws ClassCastException if any of the targets is not
* an instance of MapListener interface
*/
public void dispatch(Listeners listeners)
{
dispatch(listeners, true);
}
/**
* Dispatch this event to the specified listeners collection.
*
* @param listeners the listeners collection
* @param fStrict if true then any RuntimeException thrown by event
* handlers stops all further event processing and the
* exception is re-thrown; if false then all exceptions
* are logged and the process continues
*
* @throws ClassCastException if any of the targets is not
* an instance of MapListener interface
*/
public void dispatch(Listeners listeners, boolean fStrict)
{
if (listeners != null)
{
EventListener[] targets = listeners.listeners();
Span span = TracingHelper.getActiveSpan();
if (span != null)
{
span.setMetadata(Span.Metadata.LISTENER_CLASSES.key(), listeners.getListenerClassNames());
}
for (int i = targets.length; --i >= 0; )
{
MapListener target = (MapListener) targets[i];
try
{
if (shouldDispatch(target))
{
dispatch(target);
}
}
catch (RuntimeException e)
{
if (fStrict || Thread.currentThread().isInterrupted())
{
throw e;
}
else
{
Base.err(e);
}
}
}
}
}
/**
* Dispatch this event to the specified MapListener.
*
* @param listener the listener
*/
public void dispatch(MapListener listener)
{
Thread thread = Thread.currentThread();
ClassLoader loader = null;
Object oSource = getSource();
// context class loader should be set to that of the source (cache)
if (oSource instanceof ClassLoaderAware)
{
loader = thread.getContextClassLoader();
thread.setContextClassLoader(
((ClassLoaderAware) oSource).getContextClassLoader());
}
try
{
if (shouldDispatch(listener))
{
switch (getId())
{
case MapEvent.ENTRY_INSERTED:
listener.entryInserted((MapEvent) this);
break;
case MapEvent.ENTRY_UPDATED:
listener.entryUpdated((MapEvent) this);
break;
case MapEvent.ENTRY_DELETED:
listener.entryDeleted((MapEvent) this);
break;
}
}
}
finally
{
if (loader != null)
{
thread.setContextClassLoader(loader);
}
}
}
/**
* Return true if the provided {@link MapListener} should receive this
* event.
*
* @param listener the MapListener to dispatch this event to
*
* @return true if the provided MapListener should receive the event
*/
protected boolean shouldDispatch(MapListener listener)
{
return true;
}
/**
* Get the event's description.
*
* @return this event's description
*/
protected String getDescription()
{
switch (getId())
{
case ENTRY_INSERTED:
return " inserted: key=" + getKey()
+ ", value=" + getNewValue();
case ENTRY_UPDATED:
return " updated: key=" + getKey()
+ ", old value=" + getOldValue()
+ ", new value=" + getNewValue();
case ENTRY_DELETED:
return " deleted: key=" + getKey()
+ ", value=" + getOldValue();
default:
throw new IllegalStateException();
}
}
/**
* Convert an event ID into a human-readable string.
*
* @param nId an event ID, one of the ENTRY_* enumerated values
*
* @return a corresponding human-readable string, for example "inserted"
*/
public static String getDescription(int nId)
{
switch (nId)
{
case ENTRY_INSERTED:
return "inserted";
case ENTRY_UPDATED:
return "updated";
case ENTRY_DELETED:
return "deleted";
default:
return "';
}
}
// ----- constants ------------------------------------------------------
/**
* This event indicates that an entry has been added to the map.
*/
public static final int ENTRY_INSERTED = 1;
/**
* This event indicates that an entry has been updated in the map.
*/
public static final int ENTRY_UPDATED = 2;
/**
* This event indicates that an entry has been removed from the map.
*/
public static final int ENTRY_DELETED = 3;
// ----- data members ---------------------------------------------------
/**
* The event's id.
*/
@JsonbProperty("id")
protected int m_nId;
/**
* A key.
*/
@JsonbProperty("key")
protected K m_oKey;
/**
* A previous value. May be null if not known.
*/
@JsonbProperty(value = "oldValue", nillable = true)
protected V m_oValueOld;
/**
* A new value. May be null if not known.
*/
@JsonbProperty(value = "newValue", nillable = true)
protected V m_oValueNew;
}