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: BnH<-n_
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CountBean.java 5haJPWG|'
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/* 8$<jd^w
* CountData.java fU_itb(
* [QA@XBy6
* Created on 2007年1月1日, 下午4:44 0qSd#jO
* Ji SJi?
* To change this template, choose Tools | Options and locate the template under hKb-l`KO
* the Source Creation and Management node. Right-click the template and choose me@4lHBR
* Open. You can then make changes to the template in the Source Editor. A P><l@
*/ g"|QI=&_J
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package com.tot.count; Kx?3 ]
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/** y yfm
* {:c*-+?
* @author
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*/ w\KO1 Ob
public class CountBean { PgAC3%M6
private String countType; YC4S,fY`
int countId; fkWuSGi
/** Creates a new instance of CountData */ G8OLx+!0e
public CountBean() {} $O,$KAC
public void setCountType(String countTypes){ 2SEfEkk
this.countType=countTypes; g@YJ#S (}
} AQ 3n=Lr
public void setCountId(int countIds){ zghUwW |K
this.countId=countIds; tG(?PmQ
} z
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public String getCountType(){ EY;C5P4
return countType; JnH>L|G{;%
} 1Qui.],c
public int getCountId(){ =mYY8c Yl
return countId; :
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} r>4.{\C
} A 1x?_S"a
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CountCache.java ,tv
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/* =7ul,
* CountCache.java fb[f >1|
* =ZjF5,@
* Created on 2007年1月1日, 下午5:01 x3O$eKy\|5
* @U'I_`LL
* To change this template, choose Tools | Options and locate the template under vK)^;T ;
* the Source Creation and Management node. Right-click the template and choose DSad[>Uj],
* Open. You can then make changes to the template in the Source Editor. W4Nbl
*/ #+V-65v
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package com.tot.count; mR:G,XytxM
import java.util.*; ECqcK~h#E
/** Y!* \=h6h
* B!H46w~
* @author A~&Tp
*/ sG*1 ?
public class CountCache { 6j@3C`Yd
public static LinkedList list=new LinkedList(); |=2E?&%?
/** Creates a new instance of CountCache */ MHmaut#
public CountCache() {} :Lqz`
public static void add(CountBean cb){ `|e?91@vEa
if(cb!=null){ wMNtN3
list.add(cb); i6M_Gk}
} Au,xIe!t
} msOk~ZPE6\
} cx M=#Go
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CountControl.java XzGPBi
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/* ;=>4
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* CountThread.java wND0KiwH
* .t|vwx
* Created on 2007年1月1日, 下午4:57 !Vl>?U?AN
* 5xL%HX[S
* To change this template, choose Tools | Options and locate the template under >u#c\s
* the Source Creation and Management node. Right-click the template and choose (5rH72g(
* Open. You can then make changes to the template in the Source Editor. 4tU3+e5h
*/ thcj_BZ8
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package com.tot.count; Z5[TmVU
import tot.db.DBUtils; <&E3QeK
import java.sql.*; K*jV=lG
/** 7sZVN
* F`g oYwA%
* @author ,\zp&P"p
*/ P3C|DO4
public class CountControl{ Rf2$k/lZ
private static long lastExecuteTime=0;//上次更新时间 V~M>K-AL
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 {^ 1s
/** Creates a new instance of CountThread */ #aUe7~
public CountControl() {} 6[>UF!.=
public synchronized void executeUpdate(){ zk= 3L} C
Connection conn=null; E8#RG-ci
PreparedStatement ps=null; +[@Ug`5M
try{ e8O[xM
conn = DBUtils.getConnection(); ,":_=Tf.
conn.setAutoCommit(false); $ KQ7S>T
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); =FUORj\O
for(int i=0;i<CountCache.list.size();i++){ 'aMT^w4if)
CountBean cb=(CountBean)CountCache.list.getFirst(); I@~hz%'
CountCache.list.removeFirst(); s,>1n0a
ps.setInt(1, cb.getCountId()); Z'p7I}-qr
ps.executeUpdate();⑴ LyR to
//ps.addBatch();⑵ ?LAKH$t
} G>f-w F6
//int [] counts = ps.executeBatch();⑶ ;hU56lfZ)X
conn.commit(); 9v&{;
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}catch(Exception e){ 4L\bT;dQ|.
e.printStackTrace(); f@Mm{3&.
} finally{ V4'G%!NY
try{
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if(ps!=null) { VOH.EK?5
ps.clearParameters(); l&cYN2T
b
ps.close(); BtDi$d%'
ps=null; sr,8zKM)
} `P}T{!P+6
}catch(SQLException e){} l1On .s
DBUtils.closeConnection(conn); h3Kv0^{
} ] >-#T
} %tiFx:F+
public long getLast(){ HI6;=~[
return lastExecuteTime; Q|Uq.UjY
} Q| >
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public void run(){ l<0BMw S8
long now = System.currentTimeMillis(); LQ
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if ((now - lastExecuteTime) > executeSep) { *+TIF"|1
//System.out.print("lastExecuteTime:"+lastExecuteTime); UqRm\h
//System.out.print(" now:"+now+"\n"); +*-u_L\'
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); f.,ozL3*
lastExecuteTime=now; (:W=8G,p
executeUpdate(); -N+'+
} w.exLC
else{ HT7V} UiaO
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); C(7uvQ
} Q)x`'[3"7W
} ^pA|ubZ
} TUzpln
//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 vy\;#X!
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类写好了,下面是在JSP中如下调用。 3l"7 $B
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<% J2H/z5YRJ4
CountBean cb=new CountBean(); )P>Cxzs
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); h7mJXS)t|
CountCache.add(cb); bAv>?Xqa
out.print(CountCache.list.size()+"<br>"); (@Q@B%!!K
CountControl c=new CountControl(); 3#vhQ*xU
c.run(); fhlhlOg
out.print(CountCache.list.size()+"<br>"); 2)(P;[m^o
%>