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: NzNA>[$[
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CountBean.java S]E.KLR?[;
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/* m>SErxU(z
* CountData.java H<1WbM:w
*
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* Created on 2007年1月1日, 下午4:44 u_rdmyq$x/
* VcoOeAKL
* To change this template, choose Tools | Options and locate the template under ~RWktv
* the Source Creation and Management node. Right-click the template and choose )Y)pmjZaG
* Open. You can then make changes to the template in the Source Editor. -ig6w.%lk
*/ >a}f{\Q
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package com.tot.count; Y/7 $1k
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/** ZI=v.wa
* 7k8 pZ
* @author <qGu7y"
*/ 7NJhRz`_
public class CountBean { h9eMcCU
private String countType; `hb%+-lj+
int countId; >KJ+-QuO&
/** Creates a new instance of CountData */ \<g*8?yFs
public CountBean() {} t]-5 ]oI
public void setCountType(String countTypes){ NC38fiH_N
this.countType=countTypes; 4R\Hpt
} /i77
public void setCountId(int countIds){ q`r**N+zn
this.countId=countIds; >vA2A1WhW
} _]:z \TDn
public String getCountType(){ [Vma^B$7Vj
return countType; KRA/MQ^7~U
} f`Fi#EKT
public int getCountId(){
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return countId; ukUGvK
} |vw"[7_aS
} O6OP =K!t:
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CountCache.java k`N^Vdr
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/* r
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* CountCache.java sQ\8>[]
* q7E~+p(>(
* Created on 2007年1月1日, 下午5:01 GmP@;[H"
* UNBH
* To change this template, choose Tools | Options and locate the template under <.? jc%
* the Source Creation and Management node. Right-click the template and choose P ! _rEV
* Open. You can then make changes to the template in the Source Editor. )h)]SF}
*/ r%+V8o
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package com.tot.count; .yEBOMNZ
import java.util.*; :n-]>Q>5=k
/** H7DJ~z~J
* T]c%!&^_
* @author .~7FyLl$
*/ N=7pK&NHSG
public class CountCache {
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public static LinkedList list=new LinkedList(); #%h-[/
/** Creates a new instance of CountCache */ (:>,u*x%
public CountCache() {} L}pt)w*V1j
public static void add(CountBean cb){ \}|o1Xh2
if(cb!=null){ z.;ez}6%V
list.add(cb); 7](KV" %V
} ys kO
} ,]d/Q<
} }|8_9Rx0*
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CountControl.java }WH&iES@P
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/* ,1+y/{S
* CountThread.java m()RU"WY
* !'9Feoez
* Created on 2007年1月1日, 下午4:57 @X;!92i
* z?*w8kU&>
* To change this template, choose Tools | Options and locate the template under 1`qMj0Y_
* the Source Creation and Management node. Right-click the template and choose yj.7'{mA
* Open. You can then make changes to the template in the Source Editor. =E#%'/ A;c
*/ Zm_UR*"
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package com.tot.count; ^Dn D>h@q
import tot.db.DBUtils; heC/\@B
import java.sql.*; /n{omx
/** 4i(JZN?
* NUWDc]@J*
* @author st:`y=F_
*/ %D%8^Zd_
public class CountControl{ Vg>dI&O
private static long lastExecuteTime=0;//上次更新时间 n%.7h3
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 2Ay*kmW
/** Creates a new instance of CountThread */ !C3MFm{B
public CountControl() {} S79;^X
public synchronized void executeUpdate(){ `-J%pEIza
Connection conn=null; Pama#6?OPh
PreparedStatement ps=null; j2StXq3
try{ CFMo)"
conn = DBUtils.getConnection(); yy i#Mo
,
conn.setAutoCommit(false); 1Vrh4g.l
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 5A3xVN=
for(int i=0;i<CountCache.list.size();i++){ bB1UZ O
CountBean cb=(CountBean)CountCache.list.getFirst(); c|B.n]Z
CountCache.list.removeFirst(); :*Z4yx
ps.setInt(1, cb.getCountId()); L\xk:j1[
ps.executeUpdate();⑴ Vk
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//ps.addBatch();⑵
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} >_-s8t=|
//int [] counts = ps.executeBatch();⑶ i]YV {
conn.commit(); e478U$
}catch(Exception e){ pz\
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e.printStackTrace(); 6;\I))"[
} finally{ c1k/UcEcg~
try{ fzb29 -
if(ps!=null) { m.#
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ps.clearParameters(); H8Bs<2
ps.close(); N `5,\TR2f
ps=null; F;4vPbH+
} k;AD`7(=
}catch(SQLException e){} [q)8N
DBUtils.closeConnection(conn); {JZZZY!n2
} Z'`gJ&6n
} r~jm`y
public long getLast(){ iNtaDX|%/
return lastExecuteTime; DS.RURzd{r
} K6v6ynp/
public void run(){ v7BA[j Qr
long now = System.currentTimeMillis(); oTU!R ,
if ((now - lastExecuteTime) > executeSep) { 9ifDcYl
//System.out.print("lastExecuteTime:"+lastExecuteTime); U@_dm/;0&
//System.out.print(" now:"+now+"\n"); 8_BV:o9kL
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); TN!j13,
lastExecuteTime=now; 8uc1iB
executeUpdate(); vM*-D{
} ]HKQDc'
else{ fi-WZ
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); LSa,1{
} ]/[FR 5>
} ddJQC|xR}
} L[oui,}_
//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 T! Y@`Ox
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类写好了,下面是在JSP中如下调用。 =x%dNf$e{W
:~b3^xhc^
<% 8;b(0^
CountBean cb=new CountBean(); [YRz*5
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ?*[N_'2W+
CountCache.add(cb); Y_;#UU689
out.print(CountCache.list.size()+"<br>"); b3&zjjQ
CountControl c=new CountControl(); \rx3aJl
c.run(); Y}t \4 di
out.print(CountCache.list.size()+"<br>"); FOv=!'So
%>