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: ZSs@9ej
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CountBean.java x9AFN
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/* cS'{h
* CountData.java zPxR=0|
* W7Y@]QMX
* Created on 2007年1月1日, 下午4:44 B;?)X&n|X
* /y$ Fw9R;
* To change this template, choose Tools | Options and locate the template under b*.aaOb
* the Source Creation and Management node. Right-click the template and choose k qL.ZR
* Open. You can then make changes to the template in the Source Editor.
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*/ x(cv}#}S8
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package com.tot.count; - om9 Z0e
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/** NhCucSU<K
* P1Z"}Qw
* @author E*u*LMm
*/ BvsSrse
public class CountBean { 1f<R,>
private String countType; #G.eiqh$a
int countId; aopZ-^
/** Creates a new instance of CountData */ +]nIr'V
public CountBean() {} MqB@}!
public void setCountType(String countTypes){ mEbI\!}H0
this.countType=countTypes; eb}P/
} @lF?+/=$
public void setCountId(int countIds){ t^KQ*8clG
this.countId=countIds; Ku%tM7 ad
} Ny^f'tsA
public String getCountType(){ _
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return countType; FGx)?
} Hf@4p'
public int getCountId(){ e`s1z|h
return countId; uE41"?GS
} In^mE(8YO
} Uffwzd!
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CountCache.java ",.f
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/* "qNFDr(WM
* CountCache.java K<wFr-z
* |~e"i<G#
* Created on 2007年1月1日, 下午5:01 w8w0:@0(
* l)vC=V6MG
* To change this template, choose Tools | Options and locate the template under h AAh
* the Source Creation and Management node. Right-click the template and choose *qm|A{FQR
* Open. You can then make changes to the template in the Source Editor. CYLab5A
*/ .@E5dw5
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package com.tot.count; 953qz]Q8
import java.util.*; vII{i
/** dI
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* @k&6\1/U
* @author Vf&U`K
*/ D9[19,2r`
public class CountCache { T2MC`s|`
public static LinkedList list=new LinkedList(); )b #5rQ
/** Creates a new instance of CountCache */ o 2Nu@^+
public CountCache() {} V!+iq*Z|=
public static void add(CountBean cb){ 3"7Q[9Oj
if(cb!=null){ b^Z2Vf:k]
list.add(cb); G;}WZy
} hHN[K
} ?@9v+Am!
} 6X*vCylI
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CountControl.java ud r\\5
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/* h(HpeN%`#
* CountThread.java !xfDWbvHV
* \jwG*a
* Created on 2007年1月1日, 下午4:57 1H-Y3G>jN
* ]]PNYa
* To change this template, choose Tools | Options and locate the template under 7b[sW|{
* the Source Creation and Management node. Right-click the template and choose SG)Fk *1
* Open. You can then make changes to the template in the Source Editor.
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*/ z3uR1vF'
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package com.tot.count; C P}fxDW
import tot.db.DBUtils; bO\++zOF
import java.sql.*; ^x\VMd3*w
/** pPBXUu'
* |CDM(g>%
* @author V|MHDMD=
*/
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public class CountControl{ E+lR&~mK=
private static long lastExecuteTime=0;//上次更新时间 &SE}5ddC7
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 EwzR4,r\M
/** Creates a new instance of CountThread */ ChTq !W
public CountControl() {} +Ww] %`_
public synchronized void executeUpdate(){ MW7~=T
Connection conn=null; * @4@eQF
PreparedStatement ps=null; 9fEe={ B+
try{ 'Gn>~m
conn = DBUtils.getConnection(); T]De{nH u
conn.setAutoCommit(false); SA +d4P_T
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); +c))fPuV
for(int i=0;i<CountCache.list.size();i++){ e"t0 rScA
CountBean cb=(CountBean)CountCache.list.getFirst(); $Q/@5f'T`9
CountCache.list.removeFirst(); HDHG~<s
ps.setInt(1, cb.getCountId()); -i`jS_-Cv-
ps.executeUpdate();⑴ +& B?f
//ps.addBatch();⑵ .t_t)'L
} 5G`HJ6
//int [] counts = ps.executeBatch();⑶ hI:.Qp`r
conn.commit(); ']1n?K=A
}catch(Exception e){ l;iU9<~
e.printStackTrace(); mH$tG
$
} finally{ <Q~N9W
try{ r@4A%ql<
if(ps!=null) { t(#9.b`W)
ps.clearParameters(); 2t\0vV2)/O
ps.close(); [Arf!W-QG
ps=null; &>zH.6%$
} VvyRZMR
}catch(SQLException e){} tP@NQCo
DBUtils.closeConnection(conn); i//H5D3
} |SkQe[t
} L+8ar9es
public long getLast(){ INN}xZ
return lastExecuteTime; Xf`e 4
} |Mb{0mKb
public void run(){ lcdhOjz!N
long now = System.currentTimeMillis(); {$^'oRk
if ((now - lastExecuteTime) > executeSep) { ?P'$Vxl
//System.out.print("lastExecuteTime:"+lastExecuteTime); <l<O2 l
//System.out.print(" now:"+now+"\n"); ]I\GnDJ^
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 3=.YQE0!dx
lastExecuteTime=now; ;bE/(nz M
executeUpdate(); Z A(u"T~
} 1,fR kQ
else{ r^~+<"
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); >5CK&6
} e=0]8l>\V
} %y RGN
} XDY]LAV
//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 U!(.i1^n
+HS]kF H
类写好了,下面是在JSP中如下调用。 eN=jWUoCh
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<% i1B!oZ3q
CountBean cb=new CountBean(); t1?aw<
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); j$)ogGu
CountCache.add(cb); sLr47 NC
out.print(CountCache.list.size()+"<br>"); 7 9tE
CountControl c=new CountControl(); u_k[<&$
c.run(); iJzBd7
out.print(CountCache.list.size()+"<br>"); WWunS|B!
%>