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: "U/NMGMj
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CountBean.java rC=p;BC@dD
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/* <[ g$N4
* CountData.java n r'YWW
* ANA2S*r
* Created on 2007年1月1日, 下午4:44 S&4w`hdD>~
* "k>{b:R|
* To change this template, choose Tools | Options and locate the template under {GGO')p
* the Source Creation and Management node. Right-click the template and choose zJB+C=]D7H
* Open. You can then make changes to the template in the Source Editor. 6E*Zj1KX
*/ )w}*PL
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package com.tot.count; [ *mCa:^
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/** oHP>v_X
* 2u I`$A:
* @author 9M-NItFos
*/ rRA_'t;uK
public class CountBean { tZJ
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private String countType; 1*x5/b
int countId; z=8_%r
/** Creates a new instance of CountData */ z9uEOX&2\
public CountBean() {} *y[~kWI
public void setCountType(String countTypes){ %r}KvJgd
this.countType=countTypes; '3Lx!pMhN
} lHj7O&+
public void setCountId(int countIds){ v J,xz*rc`
this.countId=countIds; ?tal/uC
} h} b^o*
public String getCountType(){ -*]9Ma<wa
return countType; Y
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} ,XF6Xsg2
public int getCountId(){ Z?G3d(YT
return countId; X\^3,k."
} w~FO:/
} `[W)6OUCx}
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CountCache.java H 29 _ /
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/* -7A!2mRiz
* CountCache.java ,R9f;BR
* sO f)/19
* Created on 2007年1月1日, 下午5:01 |SJ%
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* 5SPl#*W
* To change this template, choose Tools | Options and locate the template under e\bF_
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* the Source Creation and Management node. Right-click the template and choose b^=8%~?%4
* Open. You can then make changes to the template in the Source Editor. 56~da ){gd
*/ G%x,t-
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package com.tot.count; D3Ea2}8
import java.util.*; J~ gkGso
/** =S?-=jPtg
* mrBhvp""
* @author f~(^|~ZT
*/ ywa .cq
public class CountCache { t+Tg@~K2[>
public static LinkedList list=new LinkedList(); C(Bar#
/** Creates a new instance of CountCache */ I{P$B-
public CountCache() {} 0z2R`=)
public static void add(CountBean cb){ I7-PF?
if(cb!=null){ \=:g$_l
list.add(cb); 98%a)s)(a
} ]r{#268
} oeqJ?1=!
} (fjXp75
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CountControl.java 0eu$oel-
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/* ZI:d&~1i1
* CountThread.java mjJlXA
* Mh@ylp+q
* Created on 2007年1月1日, 下午4:57 0|3B8m
* r-DD*'R
* To change this template, choose Tools | Options and locate the template under dL Py%q
* the Source Creation and Management node. Right-click the template and choose 7JK 'vT
* Open. You can then make changes to the template in the Source Editor. ZCq\Zk1O&
*/ p<.!::* %(
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package com.tot.count; Sf8Xj|u
import tot.db.DBUtils; :zTj"P>"I
import java.sql.*; I,q~*d
/** f#JF5>o
* M)It(K8R
* @author @n y{.s+
*/ _!T$|,a
public class CountControl{ ku8Z;ONeH
private static long lastExecuteTime=0;//上次更新时间 a*@Z^5f
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ~wV98u-N
/** Creates a new instance of CountThread */ o`]FH_
public CountControl() {} m^&mCo,
public synchronized void executeUpdate(){ NQ{Z
Connection conn=null; IBHG1<3
PreparedStatement ps=null; CHSD8D
try{ HCZ%DBU96
conn = DBUtils.getConnection(); NWX%0PGZ
conn.setAutoCommit(false); x{w ?X.Nt
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); lY8Qy2k|
for(int i=0;i<CountCache.list.size();i++){ 8U$UI
CountBean cb=(CountBean)CountCache.list.getFirst(); {
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CountCache.list.removeFirst(); F}mwQ%M
ps.setInt(1, cb.getCountId()); .}op mI
ps.executeUpdate();⑴ Q9
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//ps.addBatch();⑵ ^Rh ~+
} J*k=|+[
//int [] counts = ps.executeBatch();⑶ LA3,e (e
conn.commit(); 745PCC'FK
}catch(Exception e){ 0|k[Wha#
e.printStackTrace(); ~H."{
} finally{ %zVv3p:
try{ agot
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if(ps!=null) { Vi~+C@96
ps.clearParameters(); En%o7^W++
ps.close(); ;Q 6e&Ips/
ps=null; 4IpFT; `q
} vCr$miZ
}catch(SQLException e){} l$@lk?dc
DBUtils.closeConnection(conn); IKj1{nZvDc
} 6!m#_z8qG3
} <\
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public long getLast(){ .;Yei6H
return lastExecuteTime; mSp7H!
} ?NeB_<dLa`
public void run(){ {[#
long now = System.currentTimeMillis(); !7|9r$
if ((now - lastExecuteTime) > executeSep) { BE;iC.rW
//System.out.print("lastExecuteTime:"+lastExecuteTime); 1@Gv`{v
//System.out.print(" now:"+now+"\n"); T!$HVHh&,}
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); LZ$!=vg4
lastExecuteTime=now; Qk?Jy<Ra
executeUpdate(); ,X):2_m
} < duM8
else{ *Ux"3IXO
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); A>S2BL#=
} l0)6[yXK
} ZmF32Ir
} J>|`
//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 ~0:c{v;4
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类写好了,下面是在JSP中如下调用。 X ^)5O>>|t
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<% ]P5u:~U
CountBean cb=new CountBean(); BGOI
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); -hfY:W`Dz
CountCache.add(cb); NyNu1V$
out.print(CountCache.list.size()+"<br>"); $x0F(|wxt
CountControl c=new CountControl(); W;yZ$k#q}(
c.run(); ;B@l0)7(x
out.print(CountCache.list.size()+"<br>"); @[lr
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%>