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: P!{
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CountBean.java ~ (xIG
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/* `V@{#+X
* CountData.java u $N2uFc
* VR>;{>~
* Created on 2007年1月1日, 下午4:44 $^Dx4:k<2
* 3+;}2x0-F
* To change this template, choose Tools | Options and locate the template under pNo<:p
* the Source Creation and Management node. Right-click the template and choose 05\A7.iy
* Open. You can then make changes to the template in the Source Editor. {iqH 27\E
*/ V=}b>Jo2j
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package com.tot.count; 9IKFrCO9,
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/** dE*n!@
* =>Vo|LBoe
* @author )POuH*j
*/ vv
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public class CountBean { 1FS Jqad
private String countType; \k1psqw^O
int countId; 6=kA
/** Creates a new instance of CountData */ D5]sf>~
public CountBean() {} Nw}y_Qf{
public void setCountType(String countTypes){ xV'\2n=1T
this.countType=countTypes; lK%pxqx
} TE4{W4I
public void setCountId(int countIds){ J 21D/#v
this.countId=countIds; XQhBnam%
} j(!M
public String getCountType(){ 2B7X~t>8a
return countType; xn&G`
} >_1*/o
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public int getCountId(){ zxtx~XO
return countId; cjU*
}
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} LXaT_3;
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CountCache.java 8?4j-
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/* h5&l#>8&
* CountCache.java LoLmT7
* 8oG0tX3i
* Created on 2007年1月1日, 下午5:01 B~cQl
* q28i9$Yqj\
* To change this template, choose Tools | Options and locate the template under AHP_B&s,Qe
* the Source Creation and Management node. Right-click the template and choose lkK+Fm
* Open. You can then make changes to the template in the Source Editor. @X_x?N
*/ oQ= Q}
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package com.tot.count; 1e*+k$-{
import java.util.*; *M5=PQfb
/** T=}(S4n#BX
* *doK$wYP
* @author -cCujDM#T
*/ |eIN<RY5
public class CountCache { }\`MXh's
public static LinkedList list=new LinkedList(); w} *;^n
/** Creates a new instance of CountCache */ P=eVp(/x
public CountCache() {} @^:R1c![s
public static void add(CountBean cb){ uh3%}2'P
if(cb!=null){ pGz-5afL
list.add(cb); \~1M\gZP
} *
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} D[m;rcl
} Ns2M8
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CountControl.java V<AT"vU[
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/* GFOd9=[
* CountThread.java !@!,7te
* A^_BK(EY
* Created on 2007年1月1日, 下午4:57 Mf%0Cx `
* ^!-*xH.dK
* To change this template, choose Tools | Options and locate the template under .oYUA}
* the Source Creation and Management node. Right-click the template and choose Fd-PjW/E8
* Open. You can then make changes to the template in the Source Editor. rG1l:Z)
*/ Y@N}XH<4R
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package com.tot.count; }3F8[Td.~N
import tot.db.DBUtils; FyX\S=
import java.sql.*; m(E-?VMHo
/** ~`c?&YixU
* +~\1Zgw
* @author <<gk<_7`
*/ YYHtd,0\+
public class CountControl{ ;1&%Wj"d
private static long lastExecuteTime=0;//上次更新时间 <\GP\G
private static long executeSep=60000;//定义更新间隔时间,单位毫秒
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/** Creates a new instance of CountThread */ LFob1HH*8
public CountControl() {} 9D++SU2:}
public synchronized void executeUpdate(){ )f9f_^;
Connection conn=null; X>j% y7v
PreparedStatement ps=null; O emi }
try{ `uy)][j-
conn = DBUtils.getConnection(); ulV)X/]1
conn.setAutoCommit(false); xz5 Jli
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); jXkz,]Iy
for(int i=0;i<CountCache.list.size();i++){ F6R+E;"4R'
CountBean cb=(CountBean)CountCache.list.getFirst(); 5\}A8Ng
CountCache.list.removeFirst(); -! Hn,93
ps.setInt(1, cb.getCountId()); L6Ykv/V
ps.executeUpdate();⑴ NS@j`6/U
//ps.addBatch();⑵ -;cZW.<
} C1^=se
//int [] counts = ps.executeBatch();⑶ 7A?~a_Ep
conn.commit(); BpZE
}catch(Exception e){ [ ps5;
e.printStackTrace(); #N_C|v/
} finally{ cq+|fg~Yy
try{ 6Y0k}+j|>E
if(ps!=null) { @6 uB78U4O
ps.clearParameters(); k'{'6JR
ps.close(); .ml24SeC
ps=null; Aa-L<wZVPt
} fOCLN$x^
}catch(SQLException e){} ;@GlJ
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DBUtils.closeConnection(conn); yB\}e'J^
} MW8GM }Ho[
} 6= s!~
public long getLast(){ ]#;;)K}>
return lastExecuteTime; >&3M
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} T1jAY^^I
public void run(){ #L5H-6nz
long now = System.currentTimeMillis(); R!b<Sg
if ((now - lastExecuteTime) > executeSep) { 6gV-u~j [#
//System.out.print("lastExecuteTime:"+lastExecuteTime); 2apR7
//System.out.print(" now:"+now+"\n"); p9Zi}!
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); =#dW^?p
lastExecuteTime=now; oBiJiPE=`
executeUpdate(); A#$oY{" 2Y
} Y3+DTR0|'
else{ iTF`sjL
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n");
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} }#5Vt
} .dX ^3
} hAtf)
//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 nI.K|hU:P
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类写好了,下面是在JSP中如下调用。 /]m5HW(P7K
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<% U8qb2'a8
CountBean cb=new CountBean(); U;u@\E@2
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ~kPHf_B;z
CountCache.add(cb); ] W39HL
out.print(CountCache.list.size()+"<br>"); $q,2VH :Ip
CountControl c=new CountControl(); -qaJ@T+J+7
c.run(); 5H#f;L\k
out.print(CountCache.list.size()+"<br>"); *Z\B9mx
%>