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: k2+Z7#2n
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CountBean.java dO8Z {wfs
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/* Bf*
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* CountData.java 9n%W-R.
* 7olA@;$
* Created on 2007年1月1日, 下午4:44 ;zJ_apZ:{
* Xs?>6i@$$
* To change this template, choose Tools | Options and locate the template under UNAuF8>K
* the Source Creation and Management node. Right-click the template and choose
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* Open. You can then make changes to the template in the Source Editor. q;AQ6k(
*/ tllg$CQ5
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package com.tot.count; -OW$
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/** mcR!P~"i
* gSv<.fD"
* @author d)AkA\neWo
*/ "l@~WE
public class CountBean { W UV Q_<i+
private String countType; o._^
int countId; g!QumRF
/** Creates a new instance of CountData */ Bl1I "B
public CountBean() {} ]f c:CR
public void setCountType(String countTypes){ q>X:z0H
this.countType=countTypes; tsa6: D
} |% kK?!e+-
public void setCountId(int countIds){ )-
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this.countId=countIds; JjCf<ktE.
} *w6N&
public String getCountType(){ PDsLJ|:yL
return countType; N1-LM9S
} >@|<1Fx|
public int getCountId(){ -Tt}M#W
return countId; $k?L?R1
} 2#[Y/p
} ~@O4>T+VW
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CountCache.java iUKj:q:
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/* E}GSii%S
* CountCache.java /6fPC;l
* M#p,Z F
* Created on 2007年1月1日, 下午5:01 ;wF|.^_2
* yUG5'<lX
* To change this template, choose Tools | Options and locate the template under $5o<Mj
* the Source Creation and Management node. Right-click the template and choose /l`XJs
* Open. You can then make changes to the template in the Source Editor. 5C&f-* Bh
*/ |q>Mw-=
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package com.tot.count; Rju8%FRO
import java.util.*; {3Rax5Ty
/**
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* Rb0{t[IU
* @author tvUvd(8w
*/
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public class CountCache { oGqv,[$qN
public static LinkedList list=new LinkedList(); ?x0yiV~dL
/** Creates a new instance of CountCache */ :6 fQE#(s&
public CountCache() {} QUDVsN#
public static void add(CountBean cb){ Ss:,#|
if(cb!=null){ +g[B &A!d+
list.add(cb); K_aN7?#.v`
} a8 1%M
} rifxr4c[X>
} `lhLIQ'j
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CountControl.java -T8
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/* lN'/Z&62
* CountThread.java F~AS(sk
* 7y\g~?5N
* Created on 2007年1月1日, 下午4:57 a*hThr+$M
* X
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* To change this template, choose Tools | Options and locate the template under "=(;l3-o
* the Source Creation and Management node. Right-click the template and choose {Jc!T:vJ
* Open. You can then make changes to the template in the Source Editor. aiHr2x6
*/ d/&|%Z
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package com.tot.count; w-$w
import tot.db.DBUtils; k
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import java.sql.*; ;`B35K
/** *
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* Uz|]}t5V
* @author \7/_+)0}'
*/ q9!9OcN2
public class CountControl{ l/^-:RRNKi
private static long lastExecuteTime=0;//上次更新时间 8957$g
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Y
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/** Creates a new instance of CountThread */ D3{lyi|8
public CountControl() {} Yn>zR I
public synchronized void executeUpdate(){ 8tMte!E
Connection conn=null; m #QI*R
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PreparedStatement ps=null; 0 l@P]_qq`
try{ l,FoK76G
conn = DBUtils.getConnection(); s>\g03=
conn.setAutoCommit(false); 6~ `bAe`}
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); [u80-x<
for(int i=0;i<CountCache.list.size();i++){ (do=o&9pm
CountBean cb=(CountBean)CountCache.list.getFirst(); hhGpB$A
CountCache.list.removeFirst(); %b;+/s2W
ps.setInt(1, cb.getCountId()); PNgMLQI6
ps.executeUpdate();⑴ %Z yPK,("
//ps.addBatch();⑵ :$aW@?zAY
} 3L?a4,Q"k}
//int [] counts = ps.executeBatch();⑶ ?8@*q6~8
conn.commit(); 9 Zm<1Fw
}catch(Exception e){ )uvFta<(
e.printStackTrace(); rj~ian
} finally{ Z!reX6
try{ vs|6ww
if(ps!=null) { _KVB~loT
ps.clearParameters(); :, [!8QP
ps.close(); #ya|{K
ps=null; 3SDWR@x&
} r5!M;hU1j
}catch(SQLException e){} rVy\,#|
DBUtils.closeConnection(conn); *hs<Ez.cC
} p0y?GNQ
} SsX05>
public long getLast(){ p,\bez
return lastExecuteTime; {K4t8T]
} [E
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public void run(){ X-#mv|3
long now = System.currentTimeMillis(); JK"uj%
if ((now - lastExecuteTime) > executeSep) { .oj" ru
//System.out.print("lastExecuteTime:"+lastExecuteTime); 43=-pyp
//System.out.print(" now:"+now+"\n"); ?]D+H%3[$i
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); o%PoSZZ
lastExecuteTime=now; Z4ov
executeUpdate(); So%1RY{)
} G@EjWZQ
else{ sFCs_u1tNN
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); V
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} !a(qqZ|s
} 0Y*gJ!a
} {mnSTL`
//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 8/?uU]#Q
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类写好了,下面是在JSP中如下调用。 EJaaW&>[
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<% RK:sQWG
CountBean cb=new CountBean(); /{MH'
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); B9)qv>m
CountCache.add(cb); p]|ME
out.print(CountCache.list.size()+"<br>"); ":#x\;
CountControl c=new CountControl(); zRoEx1
c.run(); x ETVtq
out.print(CountCache.list.size()+"<br>"); R
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