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: v>rqOI
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CountBean.java CKx\V+\O
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/* c =jcvDQ6W
* CountData.java NR;q`Xe-
* '&N: S-
* Created on 2007年1月1日, 下午4:44 iP2U]d~M
* [&1iF1)4
* To change this template, choose Tools | Options and locate the template under 6 lN?) <uQ
* the Source Creation and Management node. Right-click the template and choose 8rGl&
* Open. You can then make changes to the template in the Source Editor. {`+bW"9
*/ A,3@j@bdy
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package com.tot.count; uG2Xkj
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/** hm*Th
* $eK8GMxZ#
* @author J f\Qf
*/ 9+]ZH.(YE
public class CountBean { ;n3uV`\
private String countType; sXSj OUI
int countId; | \AbL!u
/** Creates a new instance of CountData */ 7J0 ^N7"o
public CountBean() {} Coga-: 2vu
public void setCountType(String countTypes){ yonJd
this.countType=countTypes; aw%>YrJ
} "CIpo/ebL
public void setCountId(int countIds){ OI'uH$y
this.countId=countIds; u86J.K1Q
} p#ZMABlE,P
public String getCountType(){ }9MW!Ss
return countType; bk/.<Rt
} +<'uw
public int getCountId(){ NFdJb\
return countId; w;lx:j!Vp$
} O4lxeiRgC
} {KW&wsI
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CountCache.java &Tf=~6
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/* fGu5%T,
* CountCache.java =@bXGMsV!
* Q{%HW4lg
* Created on 2007年1月1日, 下午5:01 Q'FX:[@x-S
* DH}s1mNMP
* To change this template, choose Tools | Options and locate the template under F@>w&A~K
* the Source Creation and Management node. Right-click the template and choose =_#ye}E
* Open. You can then make changes to the template in the Source Editor. &@mvw=d
*/ ZrmnQ
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package com.tot.count; /AK*aRU^
import java.util.*; G/x3wR
/** ?9o#%?6k
* 2&^,IIp
* @author ,\|n=T,
*/ ]3gYuz|
public class CountCache { ~@b9
public static LinkedList list=new LinkedList(); ==jkp
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/** Creates a new instance of CountCache */ MuCQxzvkhf
public CountCache() {} `77;MGg*
public static void add(CountBean cb){ S#dyRTmI
if(cb!=null){ '0\0SL
list.add(cb); 5pNvzw
} OGSEvfW
} Ktg&G<%J0
} 1G e)p4
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CountControl.java Hl%+F0^?
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/* Mft0Dj/
* CountThread.java 9`nP(~
* ,gFL Wb`B'
* Created on 2007年1月1日, 下午4:57 HB/
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* /u"
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* To change this template, choose Tools | Options and locate the template under >#${.+y
* the Source Creation and Management node. Right-click the template and choose 9*GL@_c
* Open. You can then make changes to the template in the Source Editor. sg! =Q+
*/ &(z8GYBr
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package com.tot.count; Apw-7*/
import tot.db.DBUtils; ZI#SYEF6
import java.sql.*; 4fU5RB7%
/** 1s^$oi}
* ^)eessZ
* @author BDB zc5Q(
*/ uK"$=v6|
public class CountControl{ ie$fMBIq
private static long lastExecuteTime=0;//上次更新时间 K'{ wncumQ
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 MJ*oeI!.=
/** Creates a new instance of CountThread */ n@yd{Rc
public CountControl() {} b&|YQW}~
public synchronized void executeUpdate(){ hc@;}a\Y
Connection conn=null; >$k4@eg!
PreparedStatement ps=null; 6`$,-(J=
try{ he#Tr'j
conn = DBUtils.getConnection(); OTy4"%
conn.setAutoCommit(false); [nhLhl4S
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); E|8s2t
for(int i=0;i<CountCache.list.size();i++){ X*p:&=o
CountBean cb=(CountBean)CountCache.list.getFirst(); #nMP(ShK
CountCache.list.removeFirst(); hg86#jq%
ps.setInt(1, cb.getCountId()); K4VPmkG
ps.executeUpdate();⑴ Is,*qrl :
//ps.addBatch();⑵ 34O+#0<y~
} FZ}C;yUPD
//int [] counts = ps.executeBatch();⑶ w
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conn.commit(); .{Eg(1At
}catch(Exception e){ }E)8soQR
e.printStackTrace(); x""Mxn]gD
} finally{ |)>GeE
try{ +Fy-~Mq
if(ps!=null) { ]i_):@
ps.clearParameters(); LcQ\?]w`]
ps.close(); {?h6*>-^Z
ps=null; Z{R=h7P
}
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}catch(SQLException e){} *{4{<O<4
DBUtils.closeConnection(conn); :,J86#S)
} `P)64So-1
} bj*v'
public long getLast(){ ,2:L{8_L
return lastExecuteTime; ht[TMdV
} [/2@=Uh-
public void run(){ {&JurZ
long now = System.currentTimeMillis(); A`r$fCt1Vi
if ((now - lastExecuteTime) > executeSep) { E%v[7 ST
//System.out.print("lastExecuteTime:"+lastExecuteTime); [wpt[zG
//System.out.print(" now:"+now+"\n"); (*^E7
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// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); c9_4ohB
lastExecuteTime=now; \)6?u_(u
executeUpdate(); -%QEzu&
} Wf&G9Be?8
else{ ?eg@
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); (}7o
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} \FaB!7*~
} ",,qFM!
} B#/~U`t*
//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 &hM,b!R|
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类写好了,下面是在JSP中如下调用。 f"}14V
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<% b ffml
CountBean cb=new CountBean(); >Gu>T\jpe.
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); A<G ;
CountCache.add(cb); V1+o3g{}
out.print(CountCache.list.size()+"<br>"); EXM/>PG
CountControl c=new CountControl(); {7MgN'4
c.run(); ywa .cq
out.print(CountCache.list.size()+"<br>"); ]V[
%>