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: [qIi_(%o
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CountBean.java pIC CjA?3@
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/* jF Bq>
* CountData.java @zT.&1;`
* n-}:D<\7
* Created on 2007年1月1日, 下午4:44 yodJGGAzk
* 4+$<G /K
* To change this template, choose Tools | Options and locate the template under ~Rs|W;
* the Source Creation and Management node. Right-click the template and choose 9hmCvQgtf
* Open. You can then make changes to the template in the Source Editor. ^G~W}z?-
*/ xX{uDMYa;
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package com.tot.count; 9bMM-~
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/** {iYu
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* 4CW/
* @author U#Wc!QN-t
*/ J=
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public class CountBean { x
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private String countType; *O)_D
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int countId; 8v*>~E/0
/** Creates a new instance of CountData */ A AH-Dj|&l
public CountBean() {} fh b &_T
public void setCountType(String countTypes){ K.*?\)&
this.countType=countTypes; N`8!h:yL
} f0IljY!.
public void setCountId(int countIds){ d?v#gW
this.countId=countIds; `JG~%0Z?}
} )XnG.T{0|
public String getCountType(){ HsR#dp+s~
return countType; uZ]B ?Z%y#
} +LV'E#h!Q
public int getCountId(){ 5y(irbk7
return countId; YRG+I GX
} L`R,4mI.W
} CbQ@l@d]
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CountCache.java Wey-nsk
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/* V*=cNj
* CountCache.java yD#w @yG
* { )'D<:T
* Created on 2007年1月1日, 下午5:01 `RthX\Tof
* !V+5$TsS
* To change this template, choose Tools | Options and locate the template under F}H!vh[
* the Source Creation and Management node. Right-click the template and choose AU^Wy|i5Q
* Open. You can then make changes to the template in the Source Editor. ~H@':Mms.h
*/ $-=aqUU
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package com.tot.count; )_GM&-
import java.util.*; ]WWre},
/** JV36@DVQ
* c5;YKON
* @author }h+a8@
*/ i_`YZ7Hxp
public class CountCache { :54|Z5h|
public static LinkedList list=new LinkedList(); Wq<>a;m
/** Creates a new instance of CountCache */ }ebw1G
public CountCache() {} rHT8a^MO
public static void add(CountBean cb){ M0=ZAsN
if(cb!=null){ &I'~:nWpt
list.add(cb); g#9w5Q
} pqMvYF
} J:?t.c~$o
} ^nbze
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CountControl.java iUS379wM}
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/* $rFv(Qc^=
* CountThread.java ;f=:~go
* .7ahz8v
* Created on 2007年1月1日, 下午4:57 p\+#`] Q7}
* /D1Bf:'(
* To change this template, choose Tools | Options and locate the template under &0(2Z^Z>fw
* the Source Creation and Management node. Right-click the template and choose 7 aDI6G
* Open. You can then make changes to the template in the Source Editor. %bDd
*/ "sT`Dhr
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package com.tot.count; *n}9_V%
import tot.db.DBUtils; {D."A$AAa
import java.sql.*; nz+o8L,
/** '3+S5p8
* R#Bt!RNZ
* @author R^1= :<)C
*/ OiM{@
public class CountControl{ ;2L=WR%
private static long lastExecuteTime=0;//上次更新时间 q hK;#<#
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 }^`{YD
/** Creates a new instance of CountThread */ Gk[P-%%b /
public CountControl() {} pxI*vgfN7
public synchronized void executeUpdate(){ (g7nMrE$j
Connection conn=null; /
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PreparedStatement ps=null; jvu,W4
try{ lz{>c.Ll[
conn = DBUtils.getConnection(); _&
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conn.setAutoCommit(false); R)<Fqa7Tm
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); s3J T1TX
for(int i=0;i<CountCache.list.size();i++){ d57(#)`
CountBean cb=(CountBean)CountCache.list.getFirst(); wTIf#y1=9
CountCache.list.removeFirst(); -)y"EJ(N
ps.setInt(1, cb.getCountId()); CvbY2_>Nh
ps.executeUpdate();⑴ ~@'|R%jJ
//ps.addBatch();⑵ &cpRB&bf
} sv0kksj
//int [] counts = ps.executeBatch();⑶ `Z%XA>
conn.commit(); cLR8U1k'
}catch(Exception e){ Ae ue:u>
e.printStackTrace(); M\`6H8aLn
} finally{ 6bHj<6>MX
try{ .*Hv^_
if(ps!=null) { A]H+rxg
ps.clearParameters(); D|=QsWZI
ps.close(); 'O{hr0q}
ps=null; Jc:G7}j6
} PU-~7h+$
}catch(SQLException e){} l_,8_u7G
DBUtils.closeConnection(conn); P92:}" )*>
} g^0
} Z: Kob
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public long getLast(){ ;P2~cQjD;
return lastExecuteTime; Jt)<RMQ^R
} =602%ef\
public void run(){ KJ9~"v
long now = System.currentTimeMillis(); ,(c="L4[
if ((now - lastExecuteTime) > executeSep) { !kV?h5@Bo
//System.out.print("lastExecuteTime:"+lastExecuteTime); l" sR\`~
//System.out.print(" now:"+now+"\n"); }DZkCzK
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); @F3 d9t-
lastExecuteTime=now; .S?,%4v%%
executeUpdate(); >`oO(d}n[0
} w~Y#[GW
else{ 8\I(a]kM`
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 8i:b~y0
} 6PPvfD^
} \ g0
} "4"L"lJ
//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 R0/~)
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类写好了,下面是在JSP中如下调用。 [Xz7.<0#U
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<% O$&p<~
CountBean cb=new CountBean(); n"dT^
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); V).M\
CountCache.add(cb); .pdgRjlSn
out.print(CountCache.list.size()+"<br>"); ?^"S%Vb
CountControl c=new CountControl(); Q2fa]*Z5
c.run(); MaMs(
out.print(CountCache.list.size()+"<br>"); C}00S{nAZ
%>