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: JcfGe4
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CountBean.java ^)a j,U[
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/* 9XUk.Nek
* CountData.java G6xNR
* b7gN|Hw5 H
* Created on 2007年1月1日, 下午4:44 Zvra > %
* LX =cx$K
* To change this template, choose Tools | Options and locate the template under 2~vvE
* the Source Creation and Management node. Right-click the template and choose c}H}fyu%n
* Open. You can then make changes to the template in the Source Editor. QC6QqcOX
*/ ]!s@FKC{;
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package com.tot.count; {z9z#8`C;
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/** EZT 8^m
* $
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* @author *Y!RU{w+Z
*/ b~<:k\EE
public class CountBean { f>&*%[fw
private String countType; *<}R=X.
int countId; %:sP #BQM
/** Creates a new instance of CountData */ "_=t1UE
public CountBean() {} bXqTc2>=
public void setCountType(String countTypes){ ,?+uQXfXR
this.countType=countTypes; +I}!)$/
} 0sCWIGUW
public void setCountId(int countIds){ 8>xd
this.countId=countIds; Lg7dJnf
} Y@ vC!C
public String getCountType(){ ~aXJ5sY"f&
return countType; ,F+,A].wG
} *)vy%\
public int getCountId(){ R0|4KT-i
return countId; ;hh.w??
} -M4VC^_
} IIF <Zkpb
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CountCache.java rX)_!mR
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/* _94R8?\_V7
* CountCache.java w$""])o,
* o"kL,&
* Created on 2007年1月1日, 下午5:01 _lC0XDZ
* 2Zg%4/u,Zp
* To change this template, choose Tools | Options and locate the template under g[\8s~g,
* the Source Creation and Management node. Right-click the template and choose -"XHN=H
* Open. You can then make changes to the template in the Source Editor. 7|o}m}yVx
*/ %zhSSB=BJ
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package com.tot.count; ,vBB". LY'
import java.util.*; &2n5m&
/** VJ1rU mO~
* -MORd{GF
* @author =)x+f/c]
*/ 1)f <
public class CountCache { H;[?8h(
public static LinkedList list=new LinkedList(); =Q6JXp
/** Creates a new instance of CountCache */ y I[kaH"J
public CountCache() {} 42:,*4t(
public static void add(CountBean cb){ RVF<l?EI4R
if(cb!=null){ /2Ok;!.
list.add(cb); 6y"T;.FAo
} [+!+Yn6:
} M<Y{Cs
} p<y\^a
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CountControl.java g!z &lQnZ
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/* JIf.d($
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* CountThread.java [ fs.D /
* S %wdXe
* Created on 2007年1月1日, 下午4:57 B3I0H6O
* >LB*5
* To change this template, choose Tools | Options and locate the template under A+z}z@K
* 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.
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*/ G-#rWZ&
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package com.tot.count; Dv4 H^
import tot.db.DBUtils; -a'D~EGB^
import java.sql.*; c(!pcB8
/** IBW-[lr7
* 6H;\Jt
* @author }*vE/W
*/ Q<yvpT(
public class CountControl{ t"5ZYa
private static long lastExecuteTime=0;//上次更新时间 >D_)z/v?"
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 s%A?B8,
/** Creates a new instance of CountThread */ aPX'CG4m
public CountControl() {} =<AG}by![
public synchronized void executeUpdate(){ SPauno <M
Connection conn=null; v|@EuN14<
PreparedStatement ps=null; jY ;Hdb''
try{ klTRuU(
conn = DBUtils.getConnection(); cqcH1aSv
conn.setAutoCommit(false); oq,*@5xV2
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); <y#@v G
for(int i=0;i<CountCache.list.size();i++){ <)"2rxX&5
CountBean cb=(CountBean)CountCache.list.getFirst(); ^KV:.up6
CountCache.list.removeFirst(); lXD=uRCI
ps.setInt(1, cb.getCountId()); 2Tv
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ps.executeUpdate();⑴ //bQD>NBO
//ps.addBatch();⑵ Fw^^sB
} R''2o_F6
//int [] counts = ps.executeBatch();⑶ ?`75ah
conn.commit(); (@=h(u .
}catch(Exception e){ pi/&WMZ<
e.printStackTrace(); vorb? iVf>
} finally{ bzZ7L-yD
try{ DW)X3A(^
if(ps!=null) { Gq7\b({=
ps.clearParameters(); Q,};O$h
ps.close(); a;&0u>
ps=null; +KOhDtLMG
} yvnvI y
}catch(SQLException e){} 2<d'!cm
DBUtils.closeConnection(conn); L:.Rv0XT
} TZdJq
} h|<;:o?yh
public long getLast(){ EH'eyC-B<
return lastExecuteTime; \@zoM:[sN
} ('.I)n
public void run(){ ;)ERxMun
long now = System.currentTimeMillis(); {
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if ((now - lastExecuteTime) > executeSep) { #(Yd'qKo
//System.out.print("lastExecuteTime:"+lastExecuteTime); ciW;sK8
//System.out.print(" now:"+now+"\n"); _6L'}X$)N
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); WY26Iq@C
lastExecuteTime=now; V h5\'Sn
executeUpdate(); 4% 6@MQ[
} dE3M
else{ ~$1g"jIw
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); aaI5x
} msOE#QL6a
} 'yh)6mid
} Jt)J1CAYo
//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 f3<2531/}
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类写好了,下面是在JSP中如下调用。 }t1 q5@QU
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<% iZ(JwY
CountBean cb=new CountBean(); vpdT2/F
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 59V8cO+qH
CountCache.add(cb); $M1;d1e6'
out.print(CountCache.list.size()+"<br>"); D8b9T.[(
CountControl c=new CountControl(); G%CS1#
c.run(); S5cs(}Bq
out.print(CountCache.list.size()+"<br>"); !)`m mr
%>