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ForwardingObject (Guava Libraries 2010.01.04)
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com.google.common.collect</FONT>
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Class ForwardingObject</H2>
<PRE>
<A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">java.lang.Object</A>
<IMG SRC="../../../../resources/inherit.gif" ALT="extended by "><B>com.google.common.collect.ForwardingObject</B>
</PRE>
<DL>
<DT><B>Direct Known Subclasses:</B> <DD><A HREF="../../../../com/google/common/collect/ForwardingCollection.html" title="class in com.google.common.collect">ForwardingCollection</A>, <A HREF="../../../../com/google/common/util/concurrent/ForwardingFuture.html" title="class in com.google.common.util.concurrent">ForwardingFuture</A>, <A HREF="../../../../com/google/common/collect/ForwardingIterator.html" title="class in com.google.common.collect">ForwardingIterator</A>, <A HREF="../../../../com/google/common/collect/ForwardingMap.html" title="class in com.google.common.collect">ForwardingMap</A>, <A HREF="../../../../com/google/common/collect/ForwardingMapEntry.html" title="class in com.google.common.collect">ForwardingMapEntry</A>, <A HREF="../../../../com/google/common/collect/ForwardingMultimap.html" title="class in com.google.common.collect">ForwardingMultimap</A>, <A HREF="../../../../com/google/common/util/concurrent/ForwardingService.html" title="class in com.google.common.util.concurrent">ForwardingService</A></DD>
</DL>
<HR>
<DL>
<DT><PRE>public abstract class <B>ForwardingObject</B><DT>extends <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</A></DL>
</PRE>
<P>
An abstract base class for implementing the <a
href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
The <A HREF="../../../../com/google/common/collect/ForwardingObject.html#delegate()"><CODE>delegate()</CODE></A> method must be overridden to return the instance
being decorated.
This class does <i>not</i> forward the <code>hashCode</code> and <code>equals</code>
methods through to the backing object, but relies on <code>Object</code>'s
implementation. This is necessary to preserve the symmetry of <code>equals</code>.
Custom definitions of equality are usually based on an interface, such as
<code>Set</code> or <code>List</code>, so that the implementation of <code>equals</code> can
cast the object being tested for equality to the custom interface. <code>ForwardingObject</code> implements no such custom interfaces directly; they
are implemented only in subclasses. Therefore, forwarding <code>equals</code>
would break symmetry, as the forwarding object might consider itself equal to
the object being tested, but the reverse could not be true. This behavior is
consistent with the JDK's collection wrappers, such as
<A HREF="http://java.sun.com/javase/6/docs/api/java/util/Collections.html?is-external=true#unmodifiableCollection(java.util.Collection)" title="class or interface in java.util"><CODE>Collections.unmodifiableCollection(java.util.Collection<? extends T>)</CODE></A>. Use an
interface-specific subclass of <code>ForwardingObject</code>, such as <A HREF="../../../../com/google/common/collect/ForwardingList.html" title="class in com.google.common.collect"><CODE>ForwardingList</CODE></A>, to preserve equality behavior, or override <code>equals</code>
directly.
<p>The <code>toString</code> method is forwarded to the delegate. Although this
class does not implement <A HREF="http://java.sun.com/javase/6/docs/api/java/io/Serializable.html?is-external=true" title="class or interface in java.io"><CODE>Serializable</CODE></A>, a serializable subclass may be
created since this class has a parameter-less constructor.
<P>
<P>
<DL>
<DT><B>Since:</B></DT>
<DD>2010.01.04 <b>stable</b> (imported from Google Collections Library)</DD>
<DT><B>Author:</B></DT>
<DD>Mike Bostock</DD>
</DL>
<HR>
<P>
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<CODE>protected </CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../com/google/common/collect/ForwardingObject.html#ForwardingObject()">ForwardingObject</A></B>()</CODE>
<BR>
Sole constructor.</TD>
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<CODE>protected abstract <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../com/google/common/collect/ForwardingObject.html#delegate()">delegate</A></B>()</CODE>
<BR>
Returns the backing delegate instance that methods are forwarded to.</TD>
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<CODE> <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../com/google/common/collect/ForwardingObject.html#toString()">toString</A></B>()</CODE>
<BR>
Returns the string representation generated by the delegate's
<code>toString</code> method.</TD>
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<TH ALIGN="left"><B>Methods inherited from class java.lang.<A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</A></B></TH>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD><CODE><A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#clone()" title="class or interface in java.lang">clone</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#equals(java.lang.Object)" title="class or interface in java.lang">equals</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#finalize()" title="class or interface in java.lang">finalize</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#getClass()" title="class or interface in java.lang">getClass</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#hashCode()" title="class or interface in java.lang">hashCode</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#notify()" title="class or interface in java.lang">notify</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#notifyAll()" title="class or interface in java.lang">notifyAll</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#wait()" title="class or interface in java.lang">wait</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#wait(long)" title="class or interface in java.lang">wait</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#wait(long, int)" title="class or interface in java.lang">wait</A></CODE></TD>
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<A NAME="ForwardingObject()"><!-- --></A><H3>
ForwardingObject</H3>
<PRE>
protected <B>ForwardingObject</B>()</PRE>
<DL>
<DD>Sole constructor.
<P>
</DL>
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<A NAME="delegate()"><!-- --></A><H3>
delegate</H3>
<PRE>
protected abstract <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</A> <B>delegate</B>()</PRE>
<DL>
<DD>Returns the backing delegate instance that methods are forwarded to.
Abstract subclasses generally override this method with an abstract method
that has a more specific return type, such as <A HREF="../../../../com/google/common/collect/ForwardingSet.html#delegate()"><CODE>ForwardingSet.delegate()</CODE></A>. Concrete subclasses override this method to supply
the instance being decorated.
<P>
<DD><DL>
</DL>
</DD>
</DL>
<HR>
<A NAME="toString()"><!-- --></A><H3>
toString</H3>
<PRE>
public <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A> <B>toString</B>()</PRE>
<DL>
<DD>Returns the string representation generated by the delegate's
<code>toString</code> method.
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#toString()" title="class or interface in java.lang">toString</A></CODE> in class <CODE><A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</A></CODE></DL>
</DD>
<DD><DL>
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