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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN""http://www.w3.org/TR/REC-html40/loose.dtd"><!--NewPage--><HTML><HEAD><!-- Generated by javadoc on Wed Jan 15 11:28:21 CET 2003 --><TITLE>Cache</TITLE><META NAME="keywords" CONTENT="javatools.util.Cache,Cache class"><LINK REL ="stylesheet" TYPE="text/css" HREF="../../stylesheet.css" TITLE="Style"></HEAD><SCRIPT>function asd(){parent.document.title="Cache";}</SCRIPT><BODY BGCOLOR="white" onload="asd();"><!-- ========== START OF NAVBAR ========== --><A NAME="navbar_top"><!-- --></A><TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0"><TR><TD COLSPAN=3 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="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-all.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></EM></TD></TR><TR><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../javatools/util/ArrayComparator.html"><B>PREV CLASS</B></A> <A HREF="../../javatools/util/Clipboard.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="Cache.html" TARGET="_top"><B>NO FRAMES</B></A> <SCRIPT> <!-- if(window==top) { document.writeln('<A HREF="../../allclasses-noframe.html" TARGET=""><B>All Classes</B></A>'); } //--></SCRIPT><NOSCRIPT><A HREF="../../allclasses-noframe.html" TARGET=""><B>All Classes</B></A></NOSCRIPT></FONT></TD></TR><TR><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> SUMMARY: NESTED | FIELD | <A HREF="#constructor_summary">CONSTR</A> | <A HREF="#method_summary">METHOD</A></FONT></TD><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">DETAIL: FIELD | <A HREF="#constructor_detail">CONSTR</A> | <A HREF="#method_detail">METHOD</A></FONT></TD></TR></TABLE><!-- =========== END OF NAVBAR =========== --><HR><!-- ======== START OF CLASS DATA ======== --><H2><FONT SIZE="-1">javatools.util</FONT><BR>Class Cache</H2><PRE>java.lang.Object | +--<B>javatools.util.Cache</B></PRE><HR><DL><DT>public class <B>Cache</B><DT>extends java.lang.Object</DL><P>General purpose cache class. Acts basically like a weak reference dictionary except that it also returns null when asked to find an item whose use-by date has expired. It works with two main data structures: A Dictionary which provides fast access into the cache, and a Queue which keeps track of the least recently used items in the cache so that old items can be removed and limit the cache to a bounded size.<P><P><HR><P><!-- ======== NESTED CLASS SUMMARY ======== --><!-- =========== FIELD SUMMARY =========== --><!-- ======== CONSTRUCTOR SUMMARY ======== --><A NAME="constructor_summary"><!-- --></A><TABLE BORDER="1" CELLPADDING="3" CELLSPACING="0" WIDTH="100%"><TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"><TD COLSPAN=2><FONT SIZE="+2"><B>Constructor Summary</B></FONT></TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD><CODE><B><A HREF="../../javatools/util/Cache.html#Cache()">Cache</A></B>()</CODE><BR> Creates a new Cache object.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD><CODE><B><A HREF="../../javatools/util/Cache.html#Cache(int)">Cache</A></B>(int size)</CODE><BR> Constructor which takes an initial guesstimate of how many items we expect to store in it</TD></TR></TABLE> <!-- ========== 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> void</CODE></FONT></TD><TD><CODE><B><A HREF="../../javatools/util/Cache.html#expire(java.lang.Object)">expire</A></B>(java.lang.Object key)</CODE><BR> Expire the item in the cache with the given key.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> java.lang.Object</CODE></FONT></TD><TD><CODE><B><A HREF="../../javatools/util/Cache.html#get(java.lang.Object)">get</A></B>(java.lang.Object key)</CODE><BR> Get an object from the cache. </TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> void</CODE></FONT></TD><TD><CODE><B><A HREF="../../javatools/util/Cache.html#put(java.lang.Object, java.lang.Object)">put</A></B>(java.lang.Object key, java.lang.Object item)</CODE><BR> Put a key value pair into the cache.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> void</CODE></FONT></TD><TD><CODE><B><A HREF="../../javatools/util/Cache.html#setCacheMaxAgeSeconds(int)">setCacheMaxAgeSeconds</A></B>(int s)</CODE><BR> Change the maximum age of items in the cache. </TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> void</CODE></FONT></TD><TD><CODE><B><A HREF="../../javatools/util/Cache.html#setCacheMaxObj(int)">setCacheMaxObj</A></B>(int n)</CODE><BR> Set the maximum number of objects to cache.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> void</CODE></FONT></TD><TD><CODE><B><A HREF="../../javatools/util/Cache.html#setNoCacheMaxAge()">setNoCacheMaxAge</A></B>()</CODE><BR> Turn off cache expiry based on age</TD></TR></TABLE> <A NAME="methods_inherited_from_class_java.lang.Object"><!-- --></A><TABLE BORDER="1" CELLPADDING="3" CELLSPACING="0" WIDTH="100%"><TR BGCOLOR="#EEEEFF" CLASS="TableSubHeadingColor"><TD><B>Methods inherited from class java.lang.Object</B></TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD><CODE>clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait</CODE></TD></TR></TABLE> <P><!-- ============ FIELD DETAIL =========== --><!-- ========= CONSTRUCTOR DETAIL ======== --><A NAME="constructor_detail"><!-- --></A><TABLE BORDER="1" CELLPADDING="3" CELLSPACING="0" WIDTH="100%"><TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"><TD COLSPAN=1><FONT SIZE="+2"><B>Constructor Detail</B></FONT></TD></TR></TABLE><A NAME="Cache()"><!-- --></A><H3>Cache</H3><PRE>public <B>Cache</B>()</PRE><DL><DD>Creates a new Cache object.<P></DL><HR><A NAME="Cache(int)"><!-- --></A><H3>Cache</H3><PRE>public <B>Cache</B>(int size)</PRE><DL><DD>Constructor which takes an initial guesstimate of how many items we expect to store in it<P><DT><B>Parameters:</B><DD><CODE>size</CODE> - The initial size.</DL><!-- ============ 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="setCacheMaxObj(int)"><!-- --></A><H3>setCacheMaxObj</H3><PRE>public void <B>setCacheMaxObj</B>(int n)</PRE><DL><DD>Set the maximum number of objects to cache.<P><DD><DL><DT><B>Parameters:</B><DD><CODE>n</CODE> - The new cacheMaxObj value</DL></DD></DL><HR><A NAME="setCacheMaxAgeSeconds(int)"><!-- --></A><H3>setCacheMaxAgeSeconds</H3><PRE>public void <B>setCacheMaxAgeSeconds</B>(int s)</PRE><DL><DD>Change the maximum age of items in the cache. Can be changed at any time.<P><DD><DL><DT><B>Parameters:</B><DD><CODE>s</CODE> - The new cacheMaxAgeSeconds value</DL></DD></DL><HR><A NAME="setNoCacheMaxAge()"><!-- --></A><H3>setNoCacheMaxAge</H3><PRE>public void <B>setNoCacheMaxAge</B>()</PRE><DL><DD>Turn off cache expiry based on age<P><DD><DL></DL></DD></DL><HR><A NAME="get(java.lang.Object)"><!-- --></A><H3>get</H3><PRE>public java.lang.Object <B>get</B>(java.lang.Object key)</PRE><DL><DD>Get an object from the cache. Returns null if the object is not in the cache.<P><DD><DL><DT><B>Parameters:</B><DD><CODE>key</CODE> - The key to use to retrieve the object<DT><B>Returns:</B><DD>The needed value.</DL></DD></DL><HR><A NAME="put(java.lang.Object, java.lang.Object)"><!-- --></A><H3>put</H3><PRE>public void <B>put</B>(java.lang.Object key, java.lang.Object item)</PRE><DL><DD>Put a key value pair into the cache.<P><DD><DL><DT><B>Parameters:</B><DD><CODE>key</CODE> - The key<DD><CODE>item</CODE> - The value</DL></DD></DL><HR><A NAME="expire(java.lang.Object)"><!-- --></A><H3>expire</H3><PRE>public void <B>expire</B>(java.lang.Object key)</PRE><DL><DD>Expire the item in the cache with the given key.<P><DD><DL><DT><B>Parameters:</B><DD><CODE>key</CODE> - The key of the object to expire from the cache.</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=3 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="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-all.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></EM></TD></TR><TR><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../javatools/util/ArrayComparator.html"><B>PREV CLASS</B></A> <A HREF="../../javatools/util/Clipboard.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="Cache.html" TARGET="_top"><B>NO FRAMES</B></A> <SCRIPT> <!-- if(window==top) { document.writeln('<A HREF="../../allclasses-noframe.html" TARGET=""><B>All Classes</B></A>'); } //--></SCRIPT><NOSCRIPT><A HREF="../../allclasses-noframe.html" TARGET=""><B>All Classes</B></A></NOSCRIPT></FONT></TD></TR><TR><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> SUMMARY: NESTED | FIELD | <A HREF="#constructor_summary">CONSTR</A> | <A HREF="#method_summary">METHOD</A></FONT></TD><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">DETAIL: FIELD | <A HREF="#constructor_detail">CONSTR</A> | <A HREF="#method_detail">METHOD</A></FONT></TD></TR></TABLE><!-- =========== END OF NAVBAR =========== --><HR></BODY></HTML>⌨️ 快捷键说明
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