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: Znv3h
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CountBean.java O?6ph4'
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/* tp6-j`7u
* CountData.java <B
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* !)Y T_ib
* Created on 2007年1月1日, 下午4:44 O}Ipg[h
* cv .R`)l
* To change this template, choose Tools | Options and locate the template under b,Z\{M:f;F
* the Source Creation and Management node. Right-click the template and choose Kzj9!'0R
* Open. You can then make changes to the template in the Source Editor. lK}W%hzU
*/ Z{9
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package com.tot.count; -3z$~
{
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/** Kx-s95t
* C
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* @author #J=@} S)
*/ 8PR1RCJ
public class CountBean { 7Fg-}lJAC
private String countType; :o)4Y
int countId; o=&tT,z
/** Creates a new instance of CountData */ p\"WX
public CountBean() {} lURL;h
public void setCountType(String countTypes){ 6X2~30pdE
this.countType=countTypes; 5IwQ<V
} WOv m%sX
public void setCountId(int countIds){ {^Y0kvnd
this.countId=countIds; *!~jHy8F
} $KmhG1*s
public String getCountType(){ #RJFJb/
return countType; 4axc05
} ceW,A`J
public int getCountId(){ U_X /
return countId; w7(jSPB
} 1x"S^j
} I6q]bQ="
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CountCache.java S)$)AN<O
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/* Id<3'ky<N
* CountCache.java 'S[&-D%(3
* L~WC9xguDl
* Created on 2007年1月1日, 下午5:01 a*qf\&Vb|
* Hn-k*Y/P
* To change this template, choose Tools | Options and locate the template under SR+<v=i
* the Source Creation and Management node. Right-click the template and choose 5kRP
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* Open. You can then make changes to the template in the Source Editor. n1"QHA
*/ [K*>W[n
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package com.tot.count; i*T>,z
import java.util.*; THFzC/~Q
/** QJsud{ada
* |uT&M`7\{
* @author +2ZBj6 e9
*/ 7QO QG:-
public class CountCache { fsA-}Qc
public static LinkedList list=new LinkedList(); f|U
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/** Creates a new instance of CountCache */ /5PV|onO
public CountCache() {} e5"?ol0
public static void add(CountBean cb){ ^Hdru]A$2
if(cb!=null){ &fIx2ZM[
list.add(cb); Ah_Ttj
} ",qcqG(
} b8>2Y'X
} JfrPK/Vn
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CountControl.java 'ot,6@~x>
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/* |%i|P)]
* CountThread.java Ot^<:\<`G
* A `H&"A
* Created on 2007年1月1日, 下午4:57 ]tu:V,q
* Q9\6Pn ]T
* To change this template, choose Tools | Options and locate the template under "I7 Sed7
* the Source Creation and Management node. Right-click the template and choose +Vf39}8
* Open. You can then make changes to the template in the Source Editor. #?V7kds]
*/ aCwb[7N
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package com.tot.count; ",pN.<F9O
import tot.db.DBUtils; ql+tqgo
import java.sql.*; +1R
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/** uia[>&2
* 3hPj;-u
* @author Zl:Z31
*/ }gfs
public class CountControl{ +RuPfw{z
private static long lastExecuteTime=0;//上次更新时间 y5v}EX`m&
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 a9w1Z4
/** Creates a new instance of CountThread */ w<4,;FFlZ/
public CountControl() {} Gx$rk<;ZW
public synchronized void executeUpdate(){ .t7mTpi
Connection conn=null; !Q0aKkMfL
PreparedStatement ps=null; '(qVA>S
try{ ,o_Ur.UJ
conn = DBUtils.getConnection(); Py3Y*YP
conn.setAutoCommit(false); ,)CRozC\}K
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 4;_<CB
for(int i=0;i<CountCache.list.size();i++){ o|FY-+
CountBean cb=(CountBean)CountCache.list.getFirst(); h|DKD.
CountCache.list.removeFirst(); RyJN=;5p
ps.setInt(1, cb.getCountId()); PN +<C7/
ps.executeUpdate();⑴ fV\ eksBF
//ps.addBatch();⑵ ?11\@d
} gO E3x^X*{
//int [] counts = ps.executeBatch();⑶ C Q(;L{}
conn.commit(); xIrRFK9[Q
}catch(Exception e){ (ohza<X;6
e.printStackTrace(); <]/z45?
} finally{ (t{m(;/
try{ dp&bcR)
if(ps!=null) { 4ZRE3^y\"
ps.clearParameters(); .&Vyo<9Ck
ps.close(); o
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ps=null; p{sbf;-x}
} W$l%= /
}catch(SQLException e){} x;G~c5
DBUtils.closeConnection(conn); ub#>kCL9
} il)LkZ@
} .\W6XRw
public long getLast(){ \Jcj4
return lastExecuteTime; 6*cY[R|q!
} @eQo
public void run(){ w'Cn3b)`
long now = System.currentTimeMillis(); RCS91[
if ((now - lastExecuteTime) > executeSep) { f a9n6uT
//System.out.print("lastExecuteTime:"+lastExecuteTime); cITF=Ez
//System.out.print(" now:"+now+"\n"); :EXH8n&|
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); N~w4|q!]
lastExecuteTime=now; mJ>@Dh3>G
executeUpdate(); bhIyq4N
} @aA1=9-L
else{ -quWnn/
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); CQLh;W`Dc
} gEE6O%]g
} CUS^j
} z_jTR[dY
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 kH)JBx.
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类写好了,下面是在JSP中如下调用。 mp{r$tc
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<% HfF4BQxm
CountBean cb=new CountBean(); #*g .hL<
cb.setCountId(Integer.parseInt(request.getParameter("cid")));
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CountCache.add(cb); zeXMi:X
out.print(CountCache.list.size()+"<br>"); ~4{E0om@
CountControl c=new CountControl(); LGOeBEAMV^
c.run(); &SzLEbU!
out.print(CountCache.list.size()+"<br>"); 5&uS700
%>