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: nb*`GE
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CountBean.java $&jVEMia
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/* VTX6_&Hc1g
* CountData.java f"4w@X2F
* x lsAct:
* Created on 2007年1月1日, 下午4:44 I2)2'j,B
* 4T~wnTH0Xg
* To change this template, choose Tools | Options and locate the template under |WT]s B0Eq
* the Source Creation and Management node. Right-click the template and choose &
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* Open. You can then make changes to the template in the Source Editor. j]mnH`#BL
*/ r0pwKRE~t
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package com.tot.count; _0ZBG(
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/** Nn?$}g
* * vqUOh
* @author l?xd3Z@7[
*/ g^jTdrW/s
public class CountBean { vr6YE;Rs
private String countType; /z}b1m+
int countId; =?\%E[j
/** Creates a new instance of CountData */ `Hu2a]e9
public CountBean() {} u2[L^]|
public void setCountType(String countTypes){ d+
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this.countType=countTypes; ZC^NhgX
} uA t{WDHm
public void setCountId(int countIds){ _ib
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this.countId=countIds; AW!A+?F6
} Ue>{n{H"y
public String getCountType(){ #D ]CuSi
return countType; 6y^GMlsI
} {lppv(U
public int getCountId(){ U+["b-c
return countId; >4+KEK
} h$6~3^g:P
} lO 0}
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CountCache.java I_R 6
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/* L7.SH#m
* CountCache.java P%!=Rj^ 2m
* Cm"S=gV
* Created on 2007年1月1日, 下午5:01 LEX @hkh
* f'M([gn^_
* To change this template, choose Tools | Options and locate the template under `UqX`MFz
* the Source Creation and Management node. Right-click the template and choose i;juwc^n}
* Open. You can then make changes to the template in the Source Editor. EiZa,}A
*/ $++O@C5
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package com.tot.count; y(^\]-fE
import java.util.*; .t&G^i'n
/** M7&G9SGZ
* P>`|.@
* @author hR.vJ2oa
*/ 5/CF_v
public class CountCache { RU>qj
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public static LinkedList list=new LinkedList(); @Q;s[Kg{!
/** Creates a new instance of CountCache */ !*?9n^PaF
public CountCache() {} @tJic|)x
public static void add(CountBean cb){ O,NVhU7,
if(cb!=null){ 8f65;lyN
list.add(cb); OF-VVIS
} y3PrLBTz
} ;=6EBP%
} ,^DP
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CountControl.java 3Y&4yIx
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/* *D9H3M[o#
* CountThread.java _,d<9 Y)
* T{yJL<
* Created on 2007年1月1日, 下午4:57 VC%.u.< F
* $3%+N|L
* To change this template, choose Tools | Options and locate the template under o-;/x)
* the Source Creation and Management node. Right-click the template and choose +F2X2e)g"
* Open. You can then make changes to the template in the Source Editor. ]M'~uTf
*/ 6}|h
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package com.tot.count; "{Y6.)x
import tot.db.DBUtils; S.<4t*,
import java.sql.*; wTG(U3{3K
/** O}}rosA
* /?Mr2!3N
* @author YhC|hDC
*/ Z aS29}
public class CountControl{ KCH`=lX
private static long lastExecuteTime=0;//上次更新时间 9b@yDq3hQ
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 tE-g]y3
/** Creates a new instance of CountThread */ M* {5> !\
public CountControl() {} Z/|=@gpw
public synchronized void executeUpdate(){ :3b02}b7
Connection conn=null; W,_2JqQp
PreparedStatement ps=null; <td]k%*+
try{ h ^s8LE3
conn = DBUtils.getConnection(); JO90TP
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conn.setAutoCommit(false); k1s5cg=n(
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); >Q?8tGfB
for(int i=0;i<CountCache.list.size();i++){ @7V~CNB+
CountBean cb=(CountBean)CountCache.list.getFirst(); >VX'`5r>uw
CountCache.list.removeFirst(); ZE~zs~z|
ps.setInt(1, cb.getCountId()); KD H<T4#x
ps.executeUpdate();⑴ :F@goiuC
//ps.addBatch();⑵ ErQ6a%~,
} UP%6s:>:
//int [] counts = ps.executeBatch();⑶ mm.%Dcn
conn.commit(); 7?y7fwER
}catch(Exception e){
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e.printStackTrace();
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} finally{ ^5(d^N
try{ 5O
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if(ps!=null) { ts=:r
ps.clearParameters(); M CP GDr
ps.close(); y\Utm$)j
ps=null; ()F{kM8
}
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}catch(SQLException e){} ZmNNR 1%/
DBUtils.closeConnection(conn); p(8 @
} *c&|2EsZ
} jIVD i~Ld
public long getLast(){ 2A:h&t/|C
return lastExecuteTime; \xv(&94U
} ?( z"Ub]
public void run(){ VxARJ*4=Y
long now = System.currentTimeMillis(); a6 0rJ#GD
if ((now - lastExecuteTime) > executeSep) { F[`dX
//System.out.print("lastExecuteTime:"+lastExecuteTime); E0EK88
//System.out.print(" now:"+now+"\n"); J_m@YkK
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); $ ]#WC\Hv
lastExecuteTime=now; As`=K$^Il.
executeUpdate(); CH;U_b
} ^w2 HF
else{ CyW|k
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); cDE5/!
} !\9^|Ef?
} P=\{
} P".IW.^kk~
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 +oq<}CNr{
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类写好了,下面是在JSP中如下调用。 F"O\uo:3
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<% b78~{ht`
CountBean cb=new CountBean(); (/,l0
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); xIC@$GP
CountCache.add(cb); h:r?:C>n
out.print(CountCache.list.size()+"<br>"); DuZ Zu
CountControl c=new CountControl(); %Ta"H3ZW
c.run(); x\f~Gtt7Y
out.print(CountCache.list.size()+"<br>"); Gn_DIFa
%>