有时要为每一篇文章统计其点击次数,如果每一次浏览都要更新一次库的话,那性能在访问量很大的情况下,服务器的压力就会很大了,比较好一点的方法就是先将要更新的数据缓存起来,然后每隔一段时间再利用数据库的批量处理,批量更新库。源码如下: M1q_gHA
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CountBean.java =p[a Cb
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/* m@W>ku
* CountData.java pupt__NZ)n
* 48,uO!
* Created on 2007年1月1日, 下午4:44 Yy{(XBJ~%t
* [a!)w@I:
* To change this template, choose Tools | Options and locate the template under F@b=S0}K
* the Source Creation and Management node. Right-click the template and choose @e-2]z
* Open. You can then make changes to the template in the Source Editor. ]G~Z'fs<(
*/ q $=[v
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package com.tot.count; Ki>XLX,er=
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/** AHU=`z
* tpa<)\7KJ
* @author C;%1XFzM
*/ txiX1o!/L
public class CountBean { 8<{i=V*x4
private String countType; `PT'Lakf;3
int countId; *mkVk7]c
/** Creates a new instance of CountData */ 2;x+#D8
public CountBean() {} |zJ2ZE|
public void setCountType(String countTypes){ @V Sr'?7-
this.countType=countTypes; (K('@W%\?
} q<K/q"0-l
public void setCountId(int countIds){ CY\D.Eow
this.countId=countIds; {mB!mbr
} lV9
public String getCountType(){ A@eR~Kp
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return countType; ?aguAqG$
} PU4-}!K
public int getCountId(){ _:%i6c*"
return countId; wlEK"kKU
} }lP`3e
} qYQ
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CountCache.java QZ+G2$
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/* ByacSN
* CountCache.java qCB{dp/
* 6),!sO?
* Created on 2007年1月1日, 下午5:01 R\-]$\1D
* V{fG~19
* To change this template, choose Tools | Options and locate the template under W![~"7?
* the Source Creation and Management node. Right-click the template and choose . I."q
* Open. You can then make changes to the template in the Source Editor. F\jawoO9
*/ h@TP=
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package com.tot.count; 7.]H9
import java.util.*; !Sl_qL
/** i1K$~
* PsZ>L
* @author u'^kpr`y
*/ G E? \Vm
public class CountCache { >I',%v\?@
public static LinkedList list=new LinkedList(); w&e3#p
/** Creates a new instance of CountCache */ dkeMiLm
public CountCache() {} l&5Tft
public static void add(CountBean cb){ bn7g!2
if(cb!=null){ !L<z(dV|(
list.add(cb); Gzs$0Ki=
} }Syd*%BR[
} RRQIlI<
} t*)!BZ
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CountControl.java 2%*\XPt)
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/* C{+JrHV%h
* CountThread.java ~z,qr09
* SE(c_ sX
* Created on 2007年1月1日, 下午4:57 R7KV
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* ]]e>Jym
* To change this template, choose Tools | Options and locate the template under yE~D0%Umq
* the Source Creation and Management node. Right-click the template and choose d\zUtcJwC
* Open. You can then make changes to the template in the Source Editor. y0p\Gu;3j
*/ Xq<_r^
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package com.tot.count; *aq"c9
import tot.db.DBUtils; K=r~+4F
import java.sql.*; 7#SfuZ0@
/** x0K#-
* }0f~hL24
* @author >UV}^OO
*/ \}X[0ct2!
public class CountControl{ NNwGRoDco
private static long lastExecuteTime=0;//上次更新时间 |>1#)cONW
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 *Vg) E*s
/** Creates a new instance of CountThread */ ru~!;xT
public CountControl() {} <;uM/vSi
public synchronized void executeUpdate(){ dK0H.|
Connection conn=null; awjAv8tPO!
PreparedStatement ps=null; L}'^FqO[IW
try{ }8s&~fH
conn = DBUtils.getConnection(); &|#,Bsk"@
conn.setAutoCommit(false); gVy`||z
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); <@lj\,
for(int i=0;i<CountCache.list.size();i++){ ;),,Hk
CountBean cb=(CountBean)CountCache.list.getFirst(); k8l7.e*
CountCache.list.removeFirst(); hm
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ps.setInt(1, cb.getCountId()); ~|N,{GaL
ps.executeUpdate();⑴ /a9CqK
//ps.addBatch();⑵ 9MQjSNYzo
} 9XhH*tBn7(
//int [] counts = ps.executeBatch();⑶ WF_QhKW|k
conn.commit(); ]EUQMyR
}catch(Exception e){ >>"@0tO
e.printStackTrace(); 7\ZSXQy1W
} finally{ lR9uD9Dr
try{ e,Y<$kPV
if(ps!=null) { ?RW1%+[
ps.clearParameters(); x34GRe!!
ps.close(); g \ou+M#
ps=null; q~Al[`K
} Koj9]2<0
}catch(SQLException e){} ,}"jiGgS4
DBUtils.closeConnection(conn); n)z:C{
} XHOS"o$y
} 4i5b.bU$
public long getLast(){ & JJ*?Dl
return lastExecuteTime; rvK%m_r
} F2ISg'
public void run(){ v(=0hY9
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long now = System.currentTimeMillis(); "Nz@jv?
if ((now - lastExecuteTime) > executeSep) { ^".6~{
//System.out.print("lastExecuteTime:"+lastExecuteTime); I_ kA!^
//System.out.print(" now:"+now+"\n"); {"2CI^!/U.
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ]0MuXiR
lastExecuteTime=now; 7,8TMd1`M
executeUpdate(); F%af05L[
} tmM; Z(9t
else{ <`NsX
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); uPxjW"M+
} <"xqt7f
} 12_7UWZ"
} '5~l{3Lw
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 #};Zgixo$
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类写好了,下面是在JSP中如下调用。 0PsQ
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<% fny6`_O
CountBean cb=new CountBean(); i1A<0W|
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); o;#8=q
CountCache.add(cb); OdL/%Zp}
out.print(CountCache.list.size()+"<br>"); $bfmsCcHL
CountControl c=new CountControl(); _-^mxC|M
c.run(); KaHe(
out.print(CountCache.list.size()+"<br>"); j]]5&u/l
%>