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: qSd
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CountBean.java 1:t>}[Y
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/* /b|sv$BN
* CountData.java xpk|?/6
* 9wC; m :
* Created on 2007年1月1日, 下午4:44 Cw}\t!*!
* \);rOqh
* To change this template, choose Tools | Options and locate the template under 7`}z7nk
* 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. &g!/@*[Nhh
*/ C0%%@
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package com.tot.count; 'w2;oO
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/** f-<6T
* 2YyZiOMSc
* @author ?q P}=nJ
*/ D|o@(V
public class CountBean { ||V:',#,W
private String countType; -eMRxa>
int countId; FScQS.qF
/** Creates a new instance of CountData */ ?>Aff`dHY
public CountBean() {} TRZ^$<AG
public void setCountType(String countTypes){ vF&b|V+,
this.countType=countTypes; Nz;;X\GI
} n1Jz49[r
public void setCountId(int countIds){ U6Ak"
this.countId=countIds; Pa}vmn1$
} hbeC|_+
public String getCountType(){ {/<&
return countType; (=j!P*
} +mQSlEo
public int getCountId(){ pQNFH)=nw
return countId; MQ44uHJ
} 5qy}~dQ
} kR|y0V {K*
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CountCache.java eXK`%'
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/* +b+sQ<w?.
* CountCache.java D;]%
* 7&4,',0VL
* Created on 2007年1月1日, 下午5:01 .KN]a"]
* :!$z1u8R
* To change this template, choose Tools | Options and locate the template under >Il`AR;D
* the Source Creation and Management node. Right-click the template and choose ,X^_w
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* Open. You can then make changes to the template in the Source Editor. ^v-'=1ub?
*/ 919g5f`
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package com.tot.count; =f!M=D
import java.util.*; __j8jEV
/** .TC
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* 4:$>,D\
* @author Q8y|:tb$Y
*/ M-N2>i#
public class CountCache { ozLJ#eOE9
public static LinkedList list=new LinkedList(); fP58$pwu
/** Creates a new instance of CountCache */ (, "E9.
public CountCache() {} $8k_M
public static void add(CountBean cb){ keskD
if(cb!=null){ NrcCUZ .:N
list.add(cb); @'@6vC
} Tm\[q
} c'";36y
} dH|^\IQ
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CountControl.java x[UO1% _o-
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/* Kdu\`c-lB
* CountThread.java ,rQ)TT
* x-&v|w '
* Created on 2007年1月1日, 下午4:57 r%d11[z
* a}fClI-u
* To change this template, choose Tools | Options and locate the template under p^P y,
* the Source Creation and Management node. Right-click the template and choose OPW"ABJ
* Open. You can then make changes to the template in the Source Editor. CDnz
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*/ /T[ICd2J
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package com.tot.count; RWCS
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import tot.db.DBUtils; aa8Qslm
import java.sql.*; bK\WdG\;
/** yPYJc
* ?4e6w
* @author u=o"^
*/ @BUqQ9q:
public class CountControl{ DA`sm
private static long lastExecuteTime=0;//上次更新时间 #G` ,
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 mo[<4Uks
/** Creates a new instance of CountThread */ 2F@)nh
public CountControl() {} xc.D!Iav
public synchronized void executeUpdate(){ x}'4^Cv
Connection conn=null; :xS&Y\ry
PreparedStatement ps=null; ii
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try{ BWdc^
conn = DBUtils.getConnection(); S.|kg2
conn.setAutoCommit(false); AYIz;BmWy
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Ir"Q%>K0f
for(int i=0;i<CountCache.list.size();i++){ m\M+pjz
CountBean cb=(CountBean)CountCache.list.getFirst(); s}9tK(4v
CountCache.list.removeFirst(); dqA[|bV
ps.setInt(1, cb.getCountId()); < iI6@X>
ps.executeUpdate();⑴ ++DQS9b{
//ps.addBatch();⑵ ,, %:vK+V
} VHr7GAmU
//int [] counts = ps.executeBatch();⑶ ]^jdO# #M
conn.commit(); u#WTh%/
}catch(Exception e){ /I'u/{KB
e.printStackTrace(); 9+
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} finally{ e>9Z:vY
try{ =4<S8Cp
if(ps!=null) { X|E+K
ps.clearParameters(); rw[ {@|)'z
ps.close(); aroVyUs3j
ps=null; 9<h]OXv
} ds;cfj[
}catch(SQLException e){} nVn|$ "r
DBUtils.closeConnection(conn); 4z%#ZIy3
} rn:zKTyhw
} )S}; k=kG
public long getLast(){ )9L pX
return lastExecuteTime; F4E3c4
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} lkH;N<U
public void run(){ `k]!6osZo
long now = System.currentTimeMillis(); E? eWv)//
if ((now - lastExecuteTime) > executeSep) { }?]yxa ~
//System.out.print("lastExecuteTime:"+lastExecuteTime); [~c'|E8Q
//System.out.print(" now:"+now+"\n"); <o!&Kk 9
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); _b_?9b-)D
lastExecuteTime=now; ``|RO[+2
executeUpdate(); RF~Ofi
} ^qGA!_
else{ X";ZUp
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); E<Dh_K
} 6QLQ1k`
} Fiu!!M6
} ;=+Zw1/g
//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 ,ah*!Zm.kk
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类写好了,下面是在JSP中如下调用。 =Y/fF
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<% W.`Xm(y
CountBean cb=new CountBean(); Zfy~mv$
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); (y~laW!
CountCache.add(cb); MATgJ`lsy
out.print(CountCache.list.size()+"<br>"); MuoctW
CountControl c=new CountControl(); ;=-j;x
c.run(); 6L,lq;
out.print(CountCache.list.size()+"<br>"); R'I_xjC
%>