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: !XM<`H/
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CountBean.java v~yw-}fk%
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/* w/"vf3}(9
* CountData.java \.}ZvM$
* ^b|I^TN0
* Created on 2007年1月1日, 下午4:44 =<7z
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* |a
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* To change this template, choose Tools | Options and locate the template under Xs# _AX
* the Source Creation and Management node. Right-click the template and choose JWYe~
* Open. You can then make changes to the template in the Source Editor. J@"UFL'^
*/ ,RM8D)m\
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package com.tot.count; G.^)5!By
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/** '2hy%
* 2g~ @99`
* @author <QO1Yg7}
*/ 0kNKt(_
public class CountBean { REYvFx?i
private String countType; ;obOr~Jx'5
int countId; d7mn(= &
/** Creates a new instance of CountData */ Vo+.s#wN`h
public CountBean() {} 9_nbMs
public void setCountType(String countTypes){ '=%`;?j
this.countType=countTypes; $(+xhn(O
} K0>+-p oL
public void setCountId(int countIds){ 1KbZ6Msy
this.countId=countIds; S,ea[$_
} MBU|<tc
public String getCountType(){ ;']u}Nh
return countType; @x!,iT
} .@%L8_sMR
public int getCountId(){ v|\#wrCT?
return countId; fQ~TZ:UrU
} TnKv)%VF
} F_9
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CountCache.java MmfBFt*
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/* EI7n|X
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* CountCache.java [3s-S+n
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* p5tb=Zg_
* Created on 2007年1月1日, 下午5:01 (QL:7
* ('Qq"cn#
* To change this template, choose Tools | Options and locate the template under 'S9o!hb'@
* the Source Creation and Management node. Right-click the template and choose f6yj\qq]
* Open. You can then make changes to the template in the Source Editor. ]s\vc:cc?
*/ c61OT@dZEA
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package com.tot.count; ~CbiKez
import java.util.*; pgiZA?r*<
/** 2O*At%CzW
* 6W{Nw<
* @author F8dr-"G
*/ 8>W52~^fU
public class CountCache { Du65>O
public static LinkedList list=new LinkedList(); 8h }a:/
/** Creates a new instance of CountCache */ qg=`=]j
public CountCache() {} {?Y\T
public static void add(CountBean cb){ U;4i&=.!
if(cb!=null){ uR{)%udu
list.add(cb); :aomDK*
} i{TPf1OY`M
} J]XLWAM
} t!SxJB e
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CountControl.java ygj%VG
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/* :9ia|lN
* CountThread.java OylUuYy~j
* yj#FO'UY
* Created on 2007年1月1日, 下午4:57 ZS4dW_*[
* )B"{B1(
* To change this template, choose Tools | Options and locate the template under 2uN3:_w
* the Source Creation and Management node. Right-click the template and choose DbLo{mFEIj
* Open. You can then make changes to the template in the Source Editor. dO%f ;m>#
*/ XHj%U
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package com.tot.count; 036m\7+Qj
import tot.db.DBUtils; YTZ :D/
import java.sql.*; ZD'mwj+K
/** D
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* 3<+ZA-2
* @author V 0Oqq0\
*/ }BU%<5CQ
public class CountControl{ 6vAZLNG3
private static long lastExecuteTime=0;//上次更新时间 X/cb1#
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 h U-FSdR
/** Creates a new instance of CountThread */ !reOYt|
public CountControl() {} =pi,]m
public synchronized void executeUpdate(){ Uq_lT,
Connection conn=null; iKV|~7nwO
PreparedStatement ps=null; YVa,?&i=N
try{ Zv!XNc!"$y
conn = DBUtils.getConnection(); ;`LG WT-<F
conn.setAutoCommit(false); du$M
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ?%$O7_ThvA
for(int i=0;i<CountCache.list.size();i++){ +aL
CountBean cb=(CountBean)CountCache.list.getFirst(); ,cS#
CountCache.list.removeFirst(); &'&)E((
ps.setInt(1, cb.getCountId()); }xt^}:D
ps.executeUpdate();⑴ mj e9i
//ps.addBatch();⑵ s|A[HQUtJ
} e+-#/i*
//int [] counts = ps.executeBatch();⑶ }A@:JR+|
conn.commit(); W)bSLD
}catch(Exception e){ f3G:J<cL
e.printStackTrace(); BKtb@o~(
} finally{ Z8FgxR
try{ <!FcQVH+L
if(ps!=null) { ]s0wJD=
ps.clearParameters(); ZCj1Cz]"l<
ps.close(); SyI~iW#Y1
ps=null; Qt{){uE
} iTq&h=(n
}catch(SQLException e){} tt2
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DBUtils.closeConnection(conn); oF>`>
} Z81;Y=(
} 9/e>%1.
public long getLast(){ /eH37H
return lastExecuteTime; B
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} 4]tg! ks
public void run(){ wU!-sf;]y
long now = System.currentTimeMillis(); BXU0f%"8U
if ((now - lastExecuteTime) > executeSep) { 0+op|bdj
//System.out.print("lastExecuteTime:"+lastExecuteTime); (?8i^T?WP=
//System.out.print(" now:"+now+"\n"); yUJ#LDW
// System.out.print(" sep="+(now - lastExecuteTime)+"\n");
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lastExecuteTime=now; D
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executeUpdate(); n0co*
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} x$` lQ%
else{ $Z]@N
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); !`H{jwH
} /"st
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} R|(X_A
} NYP3u_
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//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 ~Yg)8
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类写好了,下面是在JSP中如下调用。 BWxJ1ENM
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<% -hW>1s<
CountBean cb=new CountBean(); Xwo+iZ(a
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); *9r(lmrfj
CountCache.add(cb); kP[fhOpn
out.print(CountCache.list.size()+"<br>"); G\MeJSt*
CountControl c=new CountControl(); K;"oK
c.run();
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out.print(CountCache.list.size()+"<br>"); HP_h!pvx
%>