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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Frameset//EN""http://www.w3.org/TR/REC-html40/frameset.dtd"><!--NewPage--><HTML><HEAD><!-- Generated by javadoc on Thu Apr 27 23:36:44 PDT 2000 --><TITLE>Java 2 Platform SE v1.3: Interface Map.Entry</TITLE><LINK REL ="stylesheet" TYPE="text/css" HREF="../../stylesheet.css" TITLE="Style"></HEAD><BODY BGCOLOR="white"><!-- ========== START OF NAVBAR ========== --><A NAME="navbar_top"><!-- --></A><TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0"><TR><TD COLSPAN=2 BGCOLOR="#EEEEFF" CLASS="NavBarCell1"><A NAME="navbar_top_firstrow"><!-- --></A><TABLE BORDER="0" CELLPADDING="0" CELLSPACING="3"> <TR ALIGN="center" VALIGN="top"> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../overview-summary.html"><FONT CLASS="NavBarFont1"><B>Overview</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A> </TD> <TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> <FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="class-use/Map.Entry.html"><FONT CLASS="NavBarFont1"><B>Use</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../index-files/index-1.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A> </TD> </TR></TABLE></TD><TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM><b>Java<sup><font size=-2>TM</font></sup> 2 Platform<br>Std. Ed. v1.3</b></EM></TD></TR><TR><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../java/util/Map.html"><B>PREV CLASS</B></A> <A HREF="../../java/util/Observer.html"><B>NEXT CLASS</B></A></FONT></TD><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../index.html" TARGET="_top"><B>FRAMES</B></A> <A HREF="Map.Entry.html" TARGET="_top"><B>NO FRAMES</B></A></FONT></TD></TR><TR><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> SUMMARY: INNER | FIELD | CONSTR | <A HREF="#method_summary">METHOD</A></FONT></TD><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">DETAIL: FIELD | CONSTR | <A HREF="#method_detail">METHOD</A></FONT></TD></TR></TABLE><!-- =========== END OF NAVBAR =========== --><HR><!-- ======== START OF CLASS DATA ======== --><H2><FONT SIZE="-1">java.util</FONT><BR>Interface Map.Entry</H2><DL><DT><B>Enclosing class: </B><DD><A HREF="../../java/util/Map.html">Map</A></DD></DL><HR><DL><DT>public static interface <B>Map.Entry</B></DL><P>A map entry (key-value pair). The <tt>Map.entrySet</tt> method returns a collection-view of the map, whose elements are of this class. The <i>only</i> way to obtain a reference to a map entry is from the iterator of this collection-view. These <tt>Map.Entry</tt> objects are valid <i>only</i> for the duration of the iteration; more formally, the behavior of a map entry is undefined if the backing map has been modified after the entry was returned by the iterator, except through the iterator's own <tt>remove</tt> operation, or through the <tt>setValue</tt> operation on a map entry returned by the iterator.<P><DL><DT><B>Since: </B><DD>1.2</DD><DT><B>See Also: </B><DD><A HREF="../../java/util/Map.html#entrySet()"><CODE>Map.entrySet()</CODE></A></DL><HR><P><!-- ======== INNER CLASS SUMMARY ======== --><!-- =========== FIELD SUMMARY =========== --><!-- ======== CONSTRUCTOR SUMMARY ======== --><!-- ========== METHOD SUMMARY =========== --><A NAME="method_summary"><!-- --></A><TABLE BORDER="1" CELLPADDING="3" CELLSPACING="0" WIDTH="100%"><TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"><TD COLSPAN=2><FONT SIZE="+2"><B>Method Summary</B></FONT></TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> boolean</CODE></FONT></TD><TD><CODE><B><A HREF="../../java/util/Map.Entry.html#equals(java.lang.Object)">equals</A></B>(<A HREF="../../java/lang/Object.html">Object</A> o)</CODE><BR> Compares the specified object with this entry for equality.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> <A HREF="../../java/lang/Object.html">Object</A></CODE></FONT></TD><TD><CODE><B><A HREF="../../java/util/Map.Entry.html#getKey()">getKey</A></B>()</CODE><BR> Returns the key corresponding to this entry.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> <A HREF="../../java/lang/Object.html">Object</A></CODE></FONT></TD><TD><CODE><B><A HREF="../../java/util/Map.Entry.html#getValue()">getValue</A></B>()</CODE><BR> Returns the value corresponding to this entry.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> int</CODE></FONT></TD><TD><CODE><B><A HREF="../../java/util/Map.Entry.html#hashCode()">hashCode</A></B>()</CODE><BR> Returns the hash code value for this map entry.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> <A HREF="../../java/lang/Object.html">Object</A></CODE></FONT></TD><TD><CODE><B><A HREF="../../java/util/Map.Entry.html#setValue(java.lang.Object)">setValue</A></B>(<A HREF="../../java/lang/Object.html">Object</A> value)</CODE><BR> Replaces the value corresponding to this entry with the specified value (optional operation).</TD></TR></TABLE> <P><!-- ============ FIELD DETAIL =========== --><!-- ========= CONSTRUCTOR DETAIL ======== --><!-- ============ METHOD DETAIL ========== --><A NAME="method_detail"><!-- --></A><TABLE BORDER="1" CELLPADDING="3" CELLSPACING="0" WIDTH="100%"><TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"><TD COLSPAN=1><FONT SIZE="+2"><B>Method Detail</B></FONT></TD></TR></TABLE><A NAME="getKey()"><!-- --></A><H3>getKey</H3><PRE>public <A HREF="../../java/lang/Object.html">Object</A> <B>getKey</B>()</PRE><DL><DD>Returns the key corresponding to this entry.<DD><DL><DT><B>Returns:</B><DD>the key corresponding to this entry.</DL></DD></DL><HR><A NAME="getValue()"><!-- --></A><H3>getValue</H3><PRE>public <A HREF="../../java/lang/Object.html">Object</A> <B>getValue</B>()</PRE><DL><DD>Returns the value corresponding to this entry. If the mapping has been removed from the backing map (by the iterator's <tt>remove</tt> operation), the results of this call are undefined.<DD><DL><DT><B>Returns:</B><DD>the value corresponding to this entry.</DL></DD></DL><HR><A NAME="setValue(java.lang.Object)"><!-- --></A><H3>setValue</H3><PRE>public <A HREF="../../java/lang/Object.html">Object</A> <B>setValue</B>(<A HREF="../../java/lang/Object.html">Object</A> value)</PRE><DL><DD>Replaces the value corresponding to this entry with the specified value (optional operation). (Writes through to the map.) The behavior of this call is undefined if the mapping has already been removed from the map (by the iterator's <tt>remove</tt> operation).<DD><DL><DT><B>Parameters:</B><DD><CODE>value</CODE> - new value to be stored in this entry.<DT><B>Returns:</B><DD>old value corresponding to the entry.<DT><B>Throws:</B><DD><CODE><A HREF="../../java/lang/UnsupportedOperationException.html">UnsupportedOperationException</A></CODE> - if the <tt>put</tt> operation is not supported by the backing map.<DD><CODE><A HREF="../../java/lang/ClassCastException.html">ClassCastException</A></CODE> - if the class of the specified value prevents it from being stored in the backing map.<DD><CODE><A HREF="../../java/lang/IllegalArgumentException.html">IllegalArgumentException</A></CODE> - if some aspect of this value prevents it from being stored in the backing map.<DD><CODE><A HREF="../../java/lang/NullPointerException.html">NullPointerException</A></CODE> - the backing map does not permit <tt>null</tt> values, and the specified value is <tt>null</tt>.</DL></DD></DL><HR><A NAME="equals(java.lang.Object)"><!-- --></A><H3>equals</H3><PRE>public boolean <B>equals</B>(<A HREF="../../java/lang/Object.html">Object</A> o)</PRE><DL><DD>Compares the specified object with this entry for equality. Returns <tt>true</tt> if the given object is also a map entry and the two entries represent the same mapping. More formally, two entries <tt>e1</tt> and <tt>e2</tt> represent the same mapping if<pre> (e1.getKey()==null ? e2.getKey()==null : e1.getKey().equals(e2.getKey())) && (e1.getValue()==null ? e2.getValue()==null : e1.getValue().equals(e2.getValue())) </pre> This ensures that the <tt>equals</tt> method works properly across different implementations of the <tt>Map.Entry</tt> interface.<DD><DL><DT><B>Overrides:</B><DD><CODE><A HREF="../../java/lang/Object.html#equals(java.lang.Object)">equals</A></CODE> in class <CODE><A HREF="../../java/lang/Object.html">Object</A></CODE></DL></DD><DD><DL><DT><B>Parameters:</B><DD><CODE>o</CODE> - object to be compared for equality with this map entry.<DT><B>Returns:</B><DD><tt>true</tt> if the specified object is equal to this map entry.</DL></DD></DL><HR><A NAME="hashCode()"><!-- --></A><H3>hashCode</H3><PRE>public int <B>hashCode</B>()</PRE><DL><DD>Returns the hash code value for this map entry. The hash code of a map entry <tt>e</tt> is defined to be: <pre> (e.getKey()==null ? 0 : e.getKey().hashCode()) ^ (e.getValue()==null ? 0 : e.getValue().hashCode()) </pre> This ensures that <tt>e1.equals(e2)</tt> implies that <tt>e1.hashCode()==e2.hashCode()</tt> for any two Entries <tt>e1</tt> and <tt>e2</tt>, as required by the general contract of <tt>Object.hashCode</tt>.<DD><DL><DT><B>Overrides:</B><DD><CODE><A HREF="../../java/lang/Object.html#hashCode()">hashCode</A></CODE> in class <CODE><A HREF="../../java/lang/Object.html">Object</A></CODE></DL></DD><DD><DL><DT><B>Returns:</B><DD>the hash code value for this map entry.<DT><B>See Also: </B><DD><A HREF="../../java/lang/Object.html#hashCode()"><CODE>Object.hashCode()</CODE></A>, <A HREF="../../java/lang/Object.html#equals(java.lang.Object)"><CODE>Object.equals(Object)</CODE></A>, <A HREF="../../java/util/Map.Entry.html#equals(java.lang.Object)"><CODE>equals(Object)</CODE></A></DL></DD></DL><!-- ========= END OF CLASS DATA ========= --><HR><!-- ========== START OF NAVBAR ========== --><A NAME="navbar_bottom"><!-- --></A><TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0"><TR><TD COLSPAN=2 BGCOLOR="#EEEEFF" CLASS="NavBarCell1"><A NAME="navbar_bottom_firstrow"><!-- --></A><TABLE BORDER="0" CELLPADDING="0" CELLSPACING="3"> <TR ALIGN="center" VALIGN="top"> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../overview-summary.html"><FONT CLASS="NavBarFont1"><B>Overview</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A> </TD> <TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> <FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="class-use/Map.Entry.html"><FONT CLASS="NavBarFont1"><B>Use</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../index-files/index-1.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A> </TD> </TR></TABLE></TD><TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM><b>Java<sup><font size=-2>TM</font></sup> 2 Platform<br>Std. 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