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: }!eF
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CountBean.java ~wa%fM
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/* qK{|Q
* CountData.java ?OdV1xB
* UB5}i('L
* Created on 2007年1月1日, 下午4:44 1 d=0q?nH
* j~Xj
* To change this template, choose Tools | Options and locate the template under 6.k^m&-A
* the Source Creation and Management node. Right-click the template and choose -6AOK<kfI
* Open. You can then make changes to the template in the Source Editor. 9cl{hdP{
*/ Z@<q/2).|
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package com.tot.count; f:n] Exsy
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/** FrgW7`s[A
* YN_X0+b3C
* @author x&QNP
*/ /;zZnF\e
public class CountBean { 37%`P\O;s
private String countType; =%Q\*xaR.W
int countId; zNNzsT8na
/** Creates a new instance of CountData */ eL>K2Jxq
public CountBean() {} Z'voCWCd
public void setCountType(String countTypes){ 5Xp$yX =
this.countType=countTypes; 9` OG
} ,G916J*XA
public void setCountId(int countIds){ jK&
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this.countId=countIds; iSnIBs9\
} Kh>?!`lL
public String getCountType(){ ['/;'NhdlY
return countType; VC/R)%@%
} hdo+Qezu:
public int getCountId(){ }".\
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return countId; tpN]evp|
} B)(p9]q
} nwZ[Ygl|
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CountCache.java j4.Qvj >:4
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/* V`WI"HO+
* CountCache.java gn-=##fT:i
* "r5'lQI
* Created on 2007年1月1日, 下午5:01 0L3Bo3:k
* gubb .EY
* To change this template, choose Tools | Options and locate the template under =YS!soO
* the Source Creation and Management node. Right-click the template and choose ]hCWe0F
* Open. You can then make changes to the template in the Source Editor. 9nP*N`
*/ daaga}]d
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package com.tot.count; $M:4\E5(
import java.util.*; MAsWds`bpB
/** pkrl@jv >
* e_fg s>o`(
* @author !Ei Ze.K
*/ AlPL;^Y_l
public class CountCache { O^QR;<t'
public static LinkedList list=new LinkedList(); Y!K^-Y}
/** Creates a new instance of CountCache */ 9+WY@du+
public CountCache() {} *Y|lO
public static void add(CountBean cb){ 34&u]4=L)
if(cb!=null){ V Z4nAG
list.add(cb); mafAC73
} {|8:U}<#h
} eZa3K3^
} d +*T@k]>M
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CountControl.java )W_ Y3M,
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/* '=@-aVp
* CountThread.java 20SF<V
* b;&Yw-\nZ;
* Created on 2007年1月1日, 下午4:57 ~FK+bF?%
* rRF+\cP?.
* To change this template, choose Tools | Options and locate the template under $g}/T_26
* the Source Creation and Management node. Right-click the template and choose LbtlcpF*~5
* Open. You can then make changes to the template in the Source Editor. 1Ud
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*/ YyX^lL_
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package com.tot.count; >X@.f1/5X
import tot.db.DBUtils; zWKrt.Dg
import java.sql.*; fzPgX
/** K284R=j -&
* }RC.Q`b
* @author 4nVO.Ud0$X
*/ (o6A?37i
public class CountControl{ K4K3<Pg
private static long lastExecuteTime=0;//上次更新时间 -7C=- \]
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 AOvH&9**
/** Creates a new instance of CountThread */ Z.cG`Km*
public CountControl() {} 3!ajvSOI9j
public synchronized void executeUpdate(){ bOnukbJ
Connection conn=null; j,gM+4V^
PreparedStatement ps=null; DcFV^8O&
try{ .q'FSEkMJ
conn = DBUtils.getConnection(); h:US]ZC^Z
conn.setAutoCommit(false); K2vPj|
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); y7}~T!UyfF
for(int i=0;i<CountCache.list.size();i++){
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CountBean cb=(CountBean)CountCache.list.getFirst(); f6/\JVi)-
CountCache.list.removeFirst(); s525`Q;
ps.setInt(1, cb.getCountId()); ;1(qGy4
ps.executeUpdate();⑴ D%5 {A=
//ps.addBatch();⑵ YA/H;707l
} W+-f `
//int [] counts = ps.executeBatch();⑶ <try%p|f
conn.commit(); /ab K/8ZQ
}catch(Exception e){ E`sapk
e.printStackTrace(); e2VL/>y`
} finally{ ;Kq<',u~
try{ n=#[Mi $Y
if(ps!=null) { +(=[M]5#n
ps.clearParameters(); S4uR\|
ps.close(); #q^>qX
y
ps=null; sov62wuqU
} =-a?oH-
}catch(SQLException e){} y+~Aw"J}
DBUtils.closeConnection(conn); .,iw2:
} l*V72!Mv
} aV92.Z_Ku
public long getLast(){ 'E4(!H,k
return lastExecuteTime; \[hrG?A
} #f jX|b
public void run(){ 3 `C3+
long now = System.currentTimeMillis(); ~jrU#<'G9
if ((now - lastExecuteTime) > executeSep) { y|2g"J
//System.out.print("lastExecuteTime:"+lastExecuteTime); iR4,$Nn>
//System.out.print(" now:"+now+"\n"); R.n`R|NOd
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 5Dh&ez`oR'
lastExecuteTime=now; 6`{)p&9
executeUpdate();
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} E rRMiT
else{ a}I z
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); D-;43>yi<
} 'rcsK
} E`Zh\u)
} XQ?)
//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 W1M/Z[h6)5
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类写好了,下面是在JSP中如下调用。 4 9+}OIX
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<% n*]x02:LjZ
CountBean cb=new CountBean(); A5J#x6@
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); /(}l[jf
CountCache.add(cb); kQ:>j.^e
out.print(CountCache.list.size()+"<br>"); E<.{
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CountControl c=new CountControl(); J jL0/&
c.run();
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out.print(CountCache.list.size()+"<br>"); =F;^^VX
%>