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: 6 W/`07'
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CountBean.java EAUEQk?9
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/* `Gs9Xmc|
* CountData.java ?4YGT
* a,,ex i
* Created on 2007年1月1日, 下午4:44 H8=N@l
* IW5,7.
* To change this template, choose Tools | Options and locate the template under e1yt9@k,
* the Source Creation and Management node. Right-click the template and choose `>o{P/HN
* Open. You can then make changes to the template in the Source Editor. ,KH#NY]
*/ *;W+>W
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package com.tot.count; U4'#T%*
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/** { qk1_yP
* sJKI!
* @author =nHUs1rKn
*/ Lj({[H7D!
public class CountBean { PI {bmZ
private String countType; }{Pp]*I<A
int countId; ./Xz}<($8
/** Creates a new instance of CountData */ ROI7eU
public CountBean() {} ijv(9mR
public void setCountType(String countTypes){ xo^b&ktQd
this.countType=countTypes; 2DA]i5
} RHW]Z
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public void setCountId(int countIds){ AI2)g1m
this.countId=countIds; z^B,:5Tt
} D\v+wp.
public String getCountType(){ h4gXvPS&r
return countType; hPkp;a #
} =IZT(8
public int getCountId(){ ,)cM3nu
return countId; L(6d&t'|-R
} %uDi#x.
} gT.sjd
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CountCache.java aqZi:icFa
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/* ~ah~cwmpS
* CountCache.java 6q\bB
* _;S-x
* Created on 2007年1月1日, 下午5:01 (XTG8W sN
* k=$TGqQY?
* To change this template, choose Tools | Options and locate the template under tAd%#:K
* the Source Creation and Management node. Right-click the template and choose ,L2ZinU:
* Open. You can then make changes to the template in the Source Editor. l\H=m3Bg
*/ d0!5j
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package com.tot.count; 8Al{+gx@?
import java.util.*; v4TQX<0s
/** -m zIT4
* u{cW:
* @author QT5TE: D
*/ a=_g*OK}D
public class CountCache { o'aEY<mZ7
public static LinkedList list=new LinkedList(); QE+g
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/** Creates a new instance of CountCache */ /KaZHR.
public CountCache() {} b~P`qj[
public static void add(CountBean cb){ {
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if(cb!=null){ +.PxzL3?
list.add(cb); 9.M4o[
} n+9=1Oo"
} *8 A
} h+H%?:FX
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CountControl.java )AtD}HEv
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/* M]
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* CountThread.java KK4`l}Fk:n
* O`kl\K*R7
* Created on 2007年1月1日, 下午4:57 3*XNV
* }"H,h)T
* To change this template, choose Tools | Options and locate the template under R%WCH?B<}
* the Source Creation and Management node. Right-click the template and choose r|8d
4
* Open. You can then make changes to the template in the Source Editor. cl3K<'D
*/ a.\:T,cP>
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package com.tot.count; Pj^{|U2 1
import tot.db.DBUtils; wWP}C D
import java.sql.*; gs[uD5oo<
/** ?=7cF
* ~Ffo-Nd-
* @author :RTC!spy
*/ 4Z=_,#h4.
public class CountControl{ tS5hv@9cWx
private static long lastExecuteTime=0;//上次更新时间 #Vt%@*
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Jt<_zn_FG
/** Creates a new instance of CountThread */ NNR`!Pty
public CountControl() {} qr^3R&z!}
public synchronized void executeUpdate(){ ZQsJL\x[UK
Connection conn=null; 1=c\Rr9]
PreparedStatement ps=null; ZU4nc3__
try{ ,-c6dS
conn = DBUtils.getConnection(); \)904W5R
conn.setAutoCommit(false); M)+H{5bt
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); /Iy]DU8
for(int i=0;i<CountCache.list.size();i++){ A`$%SVgFV^
CountBean cb=(CountBean)CountCache.list.getFirst(); ^mDe08.
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CountCache.list.removeFirst(); VcYrK4
ps.setInt(1, cb.getCountId()); ek\ xx
ps.executeUpdate();⑴ rU:`*b<
//ps.addBatch();⑵ /t57!&
} R?|.pq/Ln
//int [] counts = ps.executeBatch();⑶ /SR*W5#s
conn.commit(); _Ey9G
}catch(Exception e){ [ ({nj`
e.printStackTrace(); %N6A+5H
} finally{ 2#]#sZmk
try{ ~$cV:O7
if(ps!=null) { Lx1FpHo
ps.clearParameters(); KP^V>9q
ps.close(); `2WFk8) F
ps=null; )[6U^j4
} ZY= {8T@
}catch(SQLException e){} ::lKL
DBUtils.closeConnection(conn); GW@;}m(
} YUD`!C
} BO;tCEV?
public long getLast(){ D,*3w'X!K
return lastExecuteTime; rQs)O<jl
} 8 +/rlHp
public void run(){ [A~xy'T
long now = System.currentTimeMillis(); iRbT/cc{
if ((now - lastExecuteTime) > executeSep) { -#[a7',Z;
//System.out.print("lastExecuteTime:"+lastExecuteTime); _ QI\
//System.out.print(" now:"+now+"\n"); 9';JXf$
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); G@\1E+Ip
lastExecuteTime=now; &j`} vg
executeUpdate(); ".V$~n(
} Id'-&tYG
else{ =l;ewlU
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); faX#**r
} X1|njJGO1
} Jb@V}Ul$
} qPK*%Q<;
//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 ~9]hV7y5C
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类写好了,下面是在JSP中如下调用。 |Nn)m
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<% o Q2Fjj
CountBean cb=new CountBean(); `Bp.RXsd*
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); *uf'zQ<9
CountCache.add(cb); 8 &LQzwa
out.print(CountCache.list.size()+"<br>"); +b<FO+E_
CountControl c=new CountControl(); $E~`\o%Ev
c.run(); _\G"9,)u'
out.print(CountCache.list.size()+"<br>"); L|:`^M+^w
%>