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: nN^lY=3
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CountBean.java x0%yz+i{:
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/* pFV~1W:
* CountData.java kkW }:dBl
* ^x$1Nf
* Created on 2007年1月1日, 下午4:44 OI8}v
* \%9QE
* To change this template, choose Tools | Options and locate the template under Q,Y^9g"B`~
* the Source Creation and Management node. Right-click the template and choose 8C?E1fH\
* Open. You can then make changes to the template in the Source Editor. .|Yn[?(
*/ p>f?Rw_
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package com.tot.count; 17`-eDd
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/** hd,O/-m#
* 4CtWEq
* @author u?rX:KkS
*/ fdHFSnQ g
public class CountBean { bR1Q77<G\
private String countType; 7F_N{avr
int countId; kZ]pV=\Y*
/** Creates a new instance of CountData */ ;@:-T/=
public CountBean() {} (Q&O'ng1
public void setCountType(String countTypes){ @6%7X7m
this.countType=countTypes; 7z&$\qu2
} mi7~(V>
public void setCountId(int countIds){ ,b5vnW\
this.countId=countIds; 6'x3g2C/
} g3yZi7b5FU
public String getCountType(){ O<$j}?2
return countType; =q|//*t2
} ; xQhq*
public int getCountId(){ nywC]T
return countId; ep0dT3&
} Dd,i^,4Gj
} -1~o~yGE
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CountCache.java Ino]::ZJ/
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/* 6.$z!~8
* CountCache.java (i?9/8I
* 9Zmq7a
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* Created on 2007年1月1日, 下午5:01 |7 Ab_
* m8G/;V[x
* To change this template, choose Tools | Options and locate the template under .JJ50p
* the Source Creation and Management node. Right-click the template and choose ksJ 1:_
* Open. You can then make changes to the template in the Source Editor. .TDg`O24c,
*/ sTep2W.9
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package com.tot.count; O(9*VoD
import java.util.*; (_+ux1h6^
/** [d-Y1
* R=$}uDFmW
* @author $9xp@8b\_
*/ e.#,9
public class CountCache { (d*||"
public static LinkedList list=new LinkedList(); QC&,C}t,
/** Creates a new instance of CountCache */ !4<A|$mQ
public CountCache() {} k*C[-5&#
public static void add(CountBean cb){ *UXa.kT@
if(cb!=null){ `s3:Vsv4
list.add(cb); !&`\MD>;~R
} l<<9H-O
} /[ft{:#&t
}
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CountControl.java 83p8:C.Ze
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/* &&m1_K
* CountThread.java )K`tnb.Pf
* Pj_DI)^
* Created on 2007年1月1日, 下午4:57 f^F"e'1
* !R#PJH/TM
* To change this template, choose Tools | Options and locate the template under sIl&\g<b
* the Source Creation and Management node. Right-click the template and choose ]2ycJ >w
* Open. You can then make changes to the template in the Source Editor. kA)`i`gt
*/ #XqiXM~^R
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package com.tot.count; tp }Bz&V
import tot.db.DBUtils; wlslG^^(!
import java.sql.*; s8qpK; O
/** Fpwhyls
* rY1jC\
* @author @xso{$ z?j
*/ ,^<39ng
public class CountControl{ +Jn\`4/J:
private static long lastExecuteTime=0;//上次更新时间 0ia-D`^me
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 v6E5#pse8
/** Creates a new instance of CountThread */ ]1|7V|N6
public CountControl() {} \q24E3zS&
public synchronized void executeUpdate(){ rSm#/)4A
Connection conn=null; gQ%mVJB{(
PreparedStatement ps=null; 8DbP$Wwi
try{ Ge=\IAj
conn = DBUtils.getConnection(); 'WBhW5@
conn.setAutoCommit(false); Y%@;\
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Tu,nX'q]m
for(int i=0;i<CountCache.list.size();i++){ '"ze Im~
CountBean cb=(CountBean)CountCache.list.getFirst(); 5B8fz;l= B
CountCache.list.removeFirst(); BO6XY90(
ps.setInt(1, cb.getCountId()); e 0Z2B2
ps.executeUpdate();⑴ D~`RLPMk
//ps.addBatch();⑵ nPl,qcyY
} ?P#\CW
//int [] counts = ps.executeBatch();⑶ JE*?O*&|Q
conn.commit(); /[Rp~YzW
}catch(Exception e){ 0;*[}M]Z
e.printStackTrace(); /q7$"wP
} finally{ PlgpH'z4$
try{ f8UO`*O
if(ps!=null) { lL5* l,)To
ps.clearParameters(); h uR ^l
ps.close(); N+H[Y4c?F&
ps=null; 322-'S3<
} 9;`hJ!r
}catch(SQLException e){} XaoVv2=G~
DBUtils.closeConnection(conn); 8,VEuBZ
} }g|9P SbJ
} / T_v8{D
public long getLast(){ O`N,aYo
return lastExecuteTime; O#>,vf$
} :!fY;c?
public void run(){ 1]A\@(
long now = System.currentTimeMillis(); G
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if ((now - lastExecuteTime) > executeSep) { V%C'@m(/SZ
//System.out.print("lastExecuteTime:"+lastExecuteTime); >fkV65w{*
//System.out.print(" now:"+now+"\n"); %zDi|WZ
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); -yu$Mm
lastExecuteTime=now; s&wm^R
executeUpdate(); hAP2DeT$
} \8vZZ t
else{ M9(lxu y1
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); "+
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} fi&>;0?7
} A8AeM`
} 1-.i^Hal
//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 7qWa>fX
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类写好了,下面是在JSP中如下调用。 %rEP.T\i
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<% T8W^qrx.v
CountBean cb=new CountBean(); qDfhR`1k
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Z *v`kl
CountCache.add(cb); }>3jHWxLc
out.print(CountCache.list.size()+"<br>"); at2)%V)
CountControl c=new CountControl(); _.EM])b
c.run(); pE0@m-p
out.print(CountCache.list.size()+"<br>"); E>2AG3)
%>