com.tangosol.util.CompositeKey Maven / Gradle / Ivy
Show all versions of coherence Show documentation
/*
* Copyright (c) 2000, 2020, Oracle and/or its affiliates.
*
* Licensed under the Universal Permissive License v 1.0 as shown at
* http://oss.oracle.com/licenses/upl.
*/
package com.tangosol.util;
import com.tangosol.io.ExternalizableLite;
import com.tangosol.io.pof.PofReader;
import com.tangosol.io.pof.PofWriter;
import com.tangosol.io.pof.PortableObject;
import com.tangosol.net.cache.KeyAssociation;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import javax.json.bind.annotation.JsonbProperty;
/**
* Key class that consists of a primary and secondary component. Two instances
* of CompositeKey are considered to be equal iff both the primary and
* secondary components of the two instances are considered equal.
* Additionally, the hash code of a CompositeKey takes into the consideration
* the hash codes of its two components. Finally, the CompositeKey class
* implements KeyAssociation by returning the primary component.
*
* @param the type of the primary component
* @param the type of the secondary component
*
* @author jh 2008.12.11
*/
public class CompositeKey
extends ExternalizableHelper
implements KeyAssociation, ExternalizableLite, PortableObject
{
// ----- constructors ---------------------------------------------------
/**
* Default constructor.
*/
public CompositeKey()
{
}
/**
* Create a new CompositeKey that consists of the given primary and
* secondary components.
*
* @param primary the primary key component; must not be null. This is
* also the host key returned by the KeyAssociation
* implementation
* @param secondary the secondary key component; must not be null
*/
public CompositeKey(P primary, S secondary)
{
if (primary == null || secondary == null)
{
throw new IllegalArgumentException();
}
m_primary = primary;
m_secondary = secondary;
}
// ----- KeyAssociation interface ---------------------------------------
/**
* {@inheritDoc}
*/
public P getAssociatedKey()
{
return m_primary;
}
// ----- ExternalizableLite interface -----------------------------------
/**
* {@inheritDoc}
*/
public void readExternal(DataInput in)
throws IOException
{
m_primary = readObject(in);
m_secondary = readObject(in);
}
/**
* {@inheritDoc}
*/
public void writeExternal(DataOutput out)
throws IOException
{
writeObject(out, m_primary);
writeObject(out, m_secondary);
}
// ----- PortableObject interface ---------------------------------------
/**
* {@inheritDoc}
*/
public void readExternal(PofReader in)
throws IOException
{
m_primary = in.readObject(0);
m_secondary = in.readObject(1);
}
/**
* {@inheritDoc}
*/
public void writeExternal(PofWriter out)
throws IOException
{
out.writeObject(0, m_primary);
out.writeObject(1, m_secondary);
}
// ----- Object methods -------------------------------------------------
/**
* Returns a hash code value for this object.
*
* @return a hash code value for this object.
*/
public int hashCode()
{
int nHash = m_nHash;
if (nHash == 0)
{
nHash = m_nHash = m_primary.hashCode() ^ m_secondary.hashCode();
}
return nHash;
}
/**
* Indicates whether some other object is "equal to" this one.
*
* @param o the reference object with which to compare.
*
* @return true if this object is the same as the obj
* argument; false otherwise.
*/
public boolean equals(Object o)
{
if (this == o)
{
return true;
}
if (o instanceof CompositeKey)
{
CompositeKey that = (CompositeKey) o;
return this.m_primary.equals(that.m_primary) &&
this.m_secondary.equals(that.m_secondary);
}
return false;
}
/**
* Returns a string representation of the object.
*
* @return a string representation of the object.
*/
public String toString()
{
return m_primary + ":" + m_secondary;
}
// ----- accessors ------------------------------------------------------
/**
* Return the primary key component.
*
* @return the primary key component
*/
public P getPrimaryKey()
{
return m_primary;
}
/**
* Return the secondary key component.
*
* @return the secondary key component
*/
public S getSecondaryKey()
{
return m_secondary;
}
// ----- data members ---------------------------------------------------
/**
* The primary key component.
*/
@JsonbProperty("primary")
private P m_primary;
/**
* The secondary key component.
*/
@JsonbProperty("secondary")
private S m_secondary;
/**
* Cached hash code.
*/
private transient int m_nHash;
}