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: w[+!c-A:H
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CountBean.java ri^yal<'
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/* 37[C^R!1c
* CountData.java 'oEmbk8Hg
* Iymz2
* Created on 2007年1月1日, 下午4:44 |S8pq4eKJ_
* '
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* To change this template, choose Tools | Options and locate the template under C;ye%&g>
* the Source Creation and Management node. Right-click the template and choose w}i.$Qt
* Open. You can then make changes to the template in the Source Editor. ,]Ma, 2
*/ gf=*m"5
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package com.tot.count; CMr`n8M
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/** c9[5)
* TGLXvP&
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* @author b1OB'P8
*/ l*u@T|Fc$
public class CountBean { k);!H +
private String countType; -5[GX3h0
int countId; x9e
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/** Creates a new instance of CountData */ N#:"X;
public CountBean() {} '$zFGq
}}
public void setCountType(String countTypes){ S!]}}fKEFm
this.countType=countTypes; J\*d4I<(Rt
} T,fz/5w
public void setCountId(int countIds){ Ame%:K!t
this.countId=countIds; Qi61(lK
} bsm,lx]bH^
public String getCountType(){ Q'VS]n
return countType; \);rOqh
} ?1uAY.~ZZB
public int getCountId(){ f/x "yUq
return countId; C0%%@
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} UQ)}i7v
} Kf4z*5Veqr
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CountCache.java Exr7vL
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/* qHCs{ u
* CountCache.java 'gGB-=yvbO
* 1N+#(<x@,
* Created on 2007年1月1日, 下午5:01 vF&b|V+,
* lu_Gr=#O
* To change this template, choose Tools | Options and locate the template under tp<V OUa
* the Source Creation and Management node. Right-click the template and choose d
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* Open. You can then make changes to the template in the Source Editor. * 5n:+Tw(
*/ +mQSlEo
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package com.tot.count; (4LLTf0
import java.util.*; B/OO$=>(
/** 7,TWCVap
* }U9jsm
* @author &}O!l'
*/ 1RA$hW@}
public class CountCache { 1'
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public static LinkedList list=new LinkedList(); cy 4'q?r
/** Creates a new instance of CountCache */ 919g5f`
public CountCache() {} YW<2:1A|
public static void add(CountBean cb){ p/h&_^EXU
if(cb!=null){ cAS_?"V
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list.add(cb); 4:$>,D\
} t5h_Q92N
} Br5Io=/wg
} F/sBr7I
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CountControl.java 9#ft;c
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/* *a!!(cZZ
* CountThread.java Ib!rf:
* 31& .Lnq
* Created on 2007年1月1日, 下午4:57 I})t
* K/`RZ!
* To change this template, choose Tools | Options and locate the template under GDp p`'\
* the Source Creation and Management node. Right-click the template and choose Q/)ok$A&
* Open. You can then make changes to the template in the Source Editor. "Q{~Bj~
*/ PU5mz.&0'
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package com.tot.count; aa8Qslm
import tot.db.DBUtils; <C;>$kX
import java.sql.*; f<Tz#w&6W
/** :)95 b fa.
* N+qLxk
* @author mo[<4Uks
*/ <0)ud)~u
public class CountControl{ ROS"VV<
private static long lastExecuteTime=0;//上次更新时间 -WvgK"k
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 h6y4Ii
/** Creates a new instance of CountThread */ AYIz;BmWy
public CountControl() {} BK9x`Oo 2
public synchronized void executeUpdate(){ d`uO7jlm
Connection conn=null; :gscW&k
PreparedStatement ps=null; lk1Gs{(qhH
try{ VHr7GAmU
conn = DBUtils.getConnection(); f&|A[i>g
conn.setAutoCommit(false); C_cs(}wi
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); (0#F]""\e
for(int i=0;i<CountCache.list.size();i++){ Q4Fq=kTE
CountBean cb=(CountBean)CountCache.list.getFirst(); rw[ {@|)'z
CountCache.list.removeFirst(); _iJXp0g
ps.setInt(1, cb.getCountId()); W^.-C
ps.executeUpdate();⑴ X2dc\v.x
//ps.addBatch();⑵ ~vSAnjeR
} jS3(>
//int [] counts = ps.executeBatch();⑶ #z!Hb&Qi\
conn.commit(); }BdVD t
}catch(Exception e){ aT:AxYn8
e.printStackTrace(); D`:d'ow~KQ
} finally{ w&yGYHg
try{ GyAgPz
if(ps!=null) { .um&6Q=2<
ps.clearParameters(); ?koxt44
ps.close(); E<Dh_K
ps=null; 1i /::4=
} $@_t5?n``F
}catch(SQLException e){} \!JS7!+
DBUtils.closeConnection(conn); [Z5[~gP3
} }PQSCl^I
} (y~laW!
public long getLast(){ Ft;u\KT
return lastExecuteTime; daB l%a=
} o4%Vt} K
public void run(){ YYE8/\+B.
long now = System.currentTimeMillis(); Cb{A:\>Q{
if ((now - lastExecuteTime) > executeSep) { +an^e'
//System.out.print("lastExecuteTime:"+lastExecuteTime); g6VD_
//System.out.print(" now:"+now+"\n"); u-QO>3oY6
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); >bA$SN
lastExecuteTime=now; K6v
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executeUpdate(); 0SMQDs5j
} |O(-CDQe
else{ 7"F|6JP"$c
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Ln=>@
}
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} xaWGa1V'z
} ,rZn`9
//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 w53z*l>ek
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类写好了,下面是在JSP中如下调用。 GG_^K#*
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<% Dd0Qp-:2
CountBean cb=new CountBean(); 4|6&59?pnc
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); X'FEOF
CountCache.add(cb); NtY*sUKRD
out.print(CountCache.list.size()+"<br>"); &[5n0e[
CountControl c=new CountControl(); YX ;n6~y
c.run(); @ /UOSU
out.print(CountCache.list.size()+"<br>"); 3>Q@r>c
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