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: j5:4/vD
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CountBean.java :/5GHfyj
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/* /({oN1X>i
* CountData.java V3cKdlu Na
* DBaZ cO(U
* Created on 2007年1月1日, 下午4:44 y>E:]#F
* @73kry v
* To change this template, choose Tools | Options and locate the template under hO3
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* the Source Creation and Management node. Right-click the template and choose $)KODI>|
* Open. You can then make changes to the template in the Source Editor. aN*{nW
*/ iZ}c[hC'3`
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package com.tot.count; #T>?g5I
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/** z?Z"*z
* d(^HO~p
* @author `<v$+mG
*/ Z}vDP^rf
public class CountBean {
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private String countType; &v;fK$=2C
int countId; <N~9=g3
/** Creates a new instance of CountData */ j[\:#/J
public CountBean() {} D bi ^%
public void setCountType(String countTypes){ T!9AEG
this.countType=countTypes; B?^~1Ua9Zv
} J;wBS w%1
public void setCountId(int countIds){ >2),HZp^I
this.countId=countIds; P=<lY},
} rf@47H
public String getCountType(){ w[3a^
return countType; t&w.Wc X)
} ~&ns?z>x
public int getCountId(){ /E\04Bs
return countId; (*6 .-Xn
} a]5y
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} rf]z5;
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CountCache.java C<T6l'S{?
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/* Qt>kythi
* CountCache.java 0$-|Th:o
* ZDp^k{AN9a
* Created on 2007年1月1日, 下午5:01 D8~\*0->
* )h0>e9z>Y
* To change this template, choose Tools | Options and locate the template under k%Tp9x$
* the Source Creation and Management node. Right-click the template and choose 2TB'HNTFx
* Open. You can then make changes to the template in the Source Editor. /\mYXi\
*/ LQ%QFfC
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package com.tot.count; `\"<%CCe
import java.util.*; *}#HBZe(9
/** [!3cWJCt
* *3={s"a.(
* @author v_U/0
0
*/ &XI9%h9|
public class CountCache { {2T u_2>
public static LinkedList list=new LinkedList(); X|!@%wuGC
/** Creates a new instance of CountCache */ > vXJ9\
public CountCache() {} (
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public static void add(CountBean cb){ A ep](je
if(cb!=null){ OMo /a%`
list.add(cb); V6c8o2G;+
}
)
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} h~qvd--p0
} u0k'Jh]K
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CountControl.java #Q["[}flVv
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/* ONpvx5'#
* CountThread.java 3w p@OF_
* BKI-Dh
* Created on 2007年1月1日, 下午4:57 q)C
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* zx:;0Z:S6>
* To change this template, choose Tools | Options and locate the template under 6+ptL-Zt<
* 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. F|!=]A<
*/ 9mXmghoCO
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package com.tot.count; ALO/{:l(
import tot.db.DBUtils; _D{FQRU<YD
import java.sql.*; t(PA+~sIp
/** `.pd %\
* nwfu@h0G
* @author SCMvq?9
*/ %q;y74
public class CountControl{ V(LfFO{^>?
private static long lastExecuteTime=0;//上次更新时间 ZR|s]'
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 u^]Gc p
/** Creates a new instance of CountThread */ AEWrrE
public CountControl() {} D(|+z-}M
public synchronized void executeUpdate(){ N`H`\+
Connection conn=null; ABp8PD
PreparedStatement ps=null; M
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try{ L$!2<eK
conn = DBUtils.getConnection(); aA>!p{/x
conn.setAutoCommit(false); y,jpd#Y
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ir\)Hz2P
for(int i=0;i<CountCache.list.size();i++){ !U2<\!_
CountBean cb=(CountBean)CountCache.list.getFirst(); *M`,#
CountCache.list.removeFirst(); Si23w'T
ps.setInt(1, cb.getCountId()); 9)=bBQyr:
ps.executeUpdate();⑴ Vx5fQ mx
//ps.addBatch();⑵ O#J7GbrHO
} %$)Sz[=
//int [] counts = ps.executeBatch();⑶ LB$0'dZU
conn.commit(); yD!GgnW
}catch(Exception e){ qJl DQc-
e.printStackTrace(); J%q)6&
} finally{ In:V.'D/>t
try{ 0%HAa|L,,
if(ps!=null) { KC9VQeSc
ps.clearParameters(); Wq 1OYZ,
ps.close(); YaQ5Z-c
ps=null; d0%Wz5Np
} 4~oRcO8!Y
}catch(SQLException e){} =1!.g"0
DBUtils.closeConnection(conn); &IDT[J
} /']`}*d
} &ns??:\+T
public long getLast(){ 9X#]Lg?b
return lastExecuteTime; [;-;{
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} 5__B
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public void run(){ V}2[chbl
long now = System.currentTimeMillis(); Lq6nmjL
if ((now - lastExecuteTime) > executeSep) { &"Cy&[
//System.out.print("lastExecuteTime:"+lastExecuteTime); `s=Z{bw
//System.out.print(" now:"+now+"\n"); 0/z$W.!
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); #\xy,C'Y
lastExecuteTime=now; 3FO-9H
executeUpdate(); EUgKJ=jw
} Dcs O~mg
else{ 4 s9^%K\8{
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); &FZ~n?;hQ
} ) R5[aO
} 7NvRZ!
} !VudZ]Sg
//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 ?wIEXKI
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类写好了,下面是在JSP中如下调用。 |vG?H#y
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<% 0f3>s>`M
CountBean cb=new CountBean(); q/@r#
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); H#nJWe_9A
CountCache.add(cb); hQL@q7tUr
out.print(CountCache.list.size()+"<br>"); YF;2jl Nm
CountControl c=new CountControl(); ?f:0GE7
c.run(); ?e+y7K}"]
out.print(CountCache.list.size()+"<br>"); r`+G9sj3U
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