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: Eb63O
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CountBean.java #UI`+2w
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/* 589fr"Ma,6
* CountData.java j
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* .pm%qEh
* Created on 2007年1月1日, 下午4:44 W_Y56@7e
* $vYy19z
* To change this template, choose Tools | Options and locate the template under yfR0vp<&
* the Source Creation and Management node. Right-click the template and choose KM"?l<x0Y
* Open. You can then make changes to the template in the Source Editor. 7!m<d,]N
*/ '"rm66
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package com.tot.count; Nlwt}7
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/** CWYOzqf
* qt"6~r!
* @author *-q&~
*/ ]W~M?1}
public class CountBean { !bnnUCTb\
private String countType; H!6&'=c {k
int countId; tI#65ox#
/** Creates a new instance of CountData */ Sz')1<
public CountBean() {} p:{L fQ
public void setCountType(String countTypes){ @KLX,1K
this.countType=countTypes; ncOl}\Q9
} ;:J"- p
public void setCountId(int countIds){
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this.countId=countIds; M\7F1\ X
} sE|8a
public String getCountType(){ VsK8 :[Al
return countType; $kMe8F_
} 6U%d3"T
public int getCountId(){ [)I
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return countId; FB>P39u
} cd=H4:<T5
} p?P.BU\CR
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CountCache.java UCFFF%
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/* s=E6HP@q
* CountCache.java xt`a":lr u
* HL>l.IG?
* Created on 2007年1月1日, 下午5:01 :fy,%su
* _z.CV<
* To change this template, choose Tools | Options and locate the template under i??+5o@uTF
* the Source Creation and Management node. Right-click the template and choose n: {f\
* Open. You can then make changes to the template in the Source Editor. <4 /q5*&
*/ |q\i, }
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package com.tot.count; > #9
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import java.util.*; BrzTOkeyG
/** j/E(*Hv
* J\'f5)k
* @author bS55/M w
*/ cP@H8|c=
public class CountCache { fmUrwI1 %
public static LinkedList list=new LinkedList(); ^r7KEeVD
/** Creates a new instance of CountCache */ .i` -t"
public CountCache() {} %P#|
}
public static void add(CountBean cb){ N#R8ez`
if(cb!=null){ GU Mf}y
list.add(cb); 9]tW; ?
} M.)z;[3O
} dI=&gz
} Z7e"4wA
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CountControl.java ,MHF
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/* 7.n\a@I/
* CountThread.java w&]$!g4
* `7V1 F.\
* Created on 2007年1月1日, 下午4:57 >^<;;8Xh
* @KZW*-"
* To change this template, choose Tools | Options and locate the template under b0se-#+
* the Source Creation and Management node. Right-click the template and choose 3k8.5W
* Open. You can then make changes to the template in the Source Editor. puEu)m^
*/ n}4q2x"
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package com.tot.count; 8hyXHe
import tot.db.DBUtils; XZ(<Mo\v
import java.sql.*; jr-9KxE
/** jgkY^l
* SVV-zz]3M
* @author mfDt_Iq
*/ *Id[6Z
public class CountControl{ RgM=g8}M
private static long lastExecuteTime=0;//上次更新时间 ~rAcT6#
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 V^}$f3\B
/** Creates a new instance of CountThread */ 6bf!v
public CountControl() {} 5pHv5e
public synchronized void executeUpdate(){ V;~\+@
Connection conn=null; Lo}/k}3Sx
PreparedStatement ps=null; _Ii=3Qsf
try{ lC
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conn = DBUtils.getConnection(); a^O>i#i
conn.setAutoCommit(false); ^b= ;
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); lx?v
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for(int i=0;i<CountCache.list.size();i++){ c+whpQ=01
CountBean cb=(CountBean)CountCache.list.getFirst(); wp:Zur5Y
CountCache.list.removeFirst(); 65mfq&"P?
ps.setInt(1, cb.getCountId()); ,k9.1kjO*)
ps.executeUpdate();⑴ i?mUQ'H
//ps.addBatch();⑵ 7 VYhRC-
} UvqnNA
//int [] counts = ps.executeBatch();⑶ Zl]@;*u
conn.commit(); E2S#REB4
}catch(Exception e){ <l+hcYam
e.printStackTrace(); cVmF'g
} finally{ I0^oaccM
try{ u:wijkx
if(ps!=null) { jOK!k
ps.clearParameters(); sY]pszjT
ps.close(); [~n|R Oo
ps=null; Sj8fo^K50
} F
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}catch(SQLException e){} mFd|JbW
DBUtils.closeConnection(conn); KyqP@
{
} AF{@lDa1h
} RyWfoLc
public long getLast(){ YnCuF0>
return lastExecuteTime; lf R}cx
} :x?G[x=
public void run(){ w2r*$Q
long now = System.currentTimeMillis(); ,1vFX$
if ((now - lastExecuteTime) > executeSep) { vEt+^3=
//System.out.print("lastExecuteTime:"+lastExecuteTime); r& :v(
//System.out.print(" now:"+now+"\n"); yK_$d0ZGE~
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); kmu7~&75
lastExecuteTime=now; .n?i'8
executeUpdate(); '3E25BsL
} ?dCJv_w
else{ ~BnmAv$m[
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); W3R43>$
} nwDGzC~y<
} $)=`Iai
} AD6 b
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 &oFgZ .
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类写好了,下面是在JSP中如下调用。 lg^Lk\Y+re
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<% {D[z>I;D
CountBean cb=new CountBean(); hN!{/Gc|
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ^j1G08W
CountCache.add(cb); :e}j$vF
out.print(CountCache.list.size()+"<br>"); 7sVO?:bj}
CountControl c=new CountControl(); P(LiH
c.run(); 0]GenT"
out.print(CountCache.list.size()+"<br>"); <jLL2-5r0
%>