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: )5y"T0]
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CountBean.java VZtFgN$J
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/* uyWw3>
* CountData.java "5?1S-Vl
* _j*I\
* Created on 2007年1月1日, 下午4:44 sD&V_
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* 3Wx\Liw,
* To change this template, choose Tools | Options and locate the template under C@<gCM j,"
* the Source Creation and Management node. Right-click the template and choose #7}YSfm^6
* Open. You can then make changes to the template in the Source Editor. xr7M#n
*/ a`?Vc}&
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package com.tot.count; <:mK&quf
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/** ;:>q;%
* <P@O{Xi+K
* @author \~t!M~H
*/ TmM~uc7mj
public class CountBean { %az6\"n
private String countType; H$pgzNL
int countId; ?IoA;GBg
/** Creates a new instance of CountData */ DF
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public CountBean() {} 6s
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public void setCountType(String countTypes){ 4gWlSm)
this.countType=countTypes; ]1W]
} )r)ZmS5O
public void setCountId(int countIds){ 8#o2 qQ2+
this.countId=countIds; \w(0k^<7
} Cb.M
public String getCountType(){ */K]sQZa
return countType; og&h$<uOZt
} LnsYtkbr
public int getCountId(){ Q&"oh
return countId; y0/FyQs
} |sP0z !)b
} 6BM$u v4
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CountCache.java s#")hMJQ
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/* |`V=hqe{
* CountCache.java !$!%era`
* iM6(bmc.
* Created on 2007年1月1日, 下午5:01 dO,;k+
* gr{*wYL
* To change this template, choose Tools | Options and locate the template under Np+pJc1
* the Source Creation and Management node. Right-click the template and choose uY/CiTWr
* Open. You can then make changes to the template in the Source Editor. {zLgLBM
*/ |YfJ#Agm+
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package com.tot.count; Q~P|=*
import java.util.*; GhjqStjS&l
/** {K?e6-N(z
* \C$cbI=;+
* @author qElPYN*wF
*/ vL^ +X`.td
public class CountCache { RZ ?SiwE
public static LinkedList list=new LinkedList(); |zd5P
/** Creates a new instance of CountCache */ w|*D{`O
public CountCache() {} !;hp
public static void add(CountBean cb){ i'^! SEt
if(cb!=null){ f|)~_JH
list.add(cb); up0=Y
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} >g@@ yR,
} 8s-X H
} ~,xso0
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CountControl.java 0($On`#
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/* }m7$,'C%P
* CountThread.java )ZFc5m^+u
* TqOH(={
* Created on 2007年1月1日, 下午4:57 J(=y$8xje
* =En1?3?
* To change this template, choose Tools | Options and locate the template under _9Rj,
* the Source Creation and Management node. Right-click the template and choose !T8sWMY
* Open. You can then make changes to the template in the Source Editor. 1rLxF{,
*/ NmF8BmIj
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package com.tot.count; &fU48n1Uh
import tot.db.DBUtils; N S*Lv
import java.sql.*; YQD/vc~8G
/** ~@[<y1g?nG
* c"t&,OU:
* @author !67xN?b
*/ ;lhW6;oI'
public class CountControl{ P 6=5:-Hh
private static long lastExecuteTime=0;//上次更新时间 ^),t=!;p
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ;W FiMM\
/** Creates a new instance of CountThread */ ez5>V7Y
public CountControl() {} HW#@e kh
public synchronized void executeUpdate(){ L 7LUy$M-<
Connection conn=null; :C,}DyZy
PreparedStatement ps=null; -pQ?ybQ
try{ E0DquVrz
conn = DBUtils.getConnection(); giW9b_
conn.setAutoCommit(false); =U8+1b
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); )a`kL,
for(int i=0;i<CountCache.list.size();i++){ }Gx@1)??
CountBean cb=(CountBean)CountCache.list.getFirst(); uf:'"7V7
CountCache.list.removeFirst(); N%e^2O)
ps.setInt(1, cb.getCountId()); ]&P 4QT)f
ps.executeUpdate();⑴ t'.:"H8BI
//ps.addBatch();⑵ }9;mtMR$
} b' ~WS4xlD
//int [] counts = ps.executeBatch();⑶ }LLQ+
conn.commit(); 5 [4{1v
}catch(Exception e){ 4nh0bI N1
e.printStackTrace(); HYY+Fv5
} finally{ Q|2*V1"r<2
try{ t"e %'dFv
if(ps!=null) { NZFUC D)
ps.clearParameters(); :()K2<E
ps.close(); \(`C*d
ps=null; L&uPNcZ`-
} _?$w8 S%
}catch(SQLException e){} cjd-B:l
DBUtils.closeConnection(conn); S?VKzVDB.S
} 2t>>08T
} ~d ~oC$=TC
public long getLast(){ G{Uqp'=G
return lastExecuteTime; A6
} @3FQMs4
public void run(){ ?@MWV
long now = System.currentTimeMillis(); &!HG.7AY
if ((now - lastExecuteTime) > executeSep) { 6q
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//System.out.print("lastExecuteTime:"+lastExecuteTime); HsT6 #K
//System.out.print(" now:"+now+"\n"); %kgT=<E'
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); j_0l'S aj
lastExecuteTime=now; m#RMd,'X
executeUpdate(); Xr88I^F;
} :&2%x
else{ B8!$?1*^a
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); R"\(a
} dX[Xe
} wjT#D|soI
} r/HG{XH`
//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 Ea0EG>Y
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类写好了,下面是在JSP中如下调用。 Y/pK
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<% J{Ld)Q,^
CountBean cb=new CountBean(); #'RfwldD9
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); yC4%z)t&R
CountCache.add(cb); f rV_5yK'
out.print(CountCache.list.size()+"<br>"); #BZ5Mxzj
CountControl c=new CountControl(); [TxvZq*4
c.run(); .SSPJY(
out.print(CountCache.list.size()+"<br>"); 4!
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