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: E6^S2J2
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CountBean.java M:Y!k<p
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/* '`goy%Wd
* CountData.java CK`3
* WbD C
* Created on 2007年1月1日, 下午4:44 ofrlTw&o
* ;|$]Qq
* To change this template, choose Tools | Options and locate the template under )i6U$,]
* the Source Creation and Management node. Right-click the template and choose $b
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* Open. You can then make changes to the template in the Source Editor. . =foXN
*/ ks`
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package com.tot.count; )'I<xx'1
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/** sxQ ,x/O
* 7!yF5+_d
* @author _ L:w;Oy9T
*/ my\oC^/9
public class CountBean { Z FrXw+
private String countType; Ef*.}gcU
int countId; sFz4^Kn
/** Creates a new instance of CountData */ nTtt$I@hW
public CountBean() {} yNMwd.r[
public void setCountType(String countTypes){ vheAh`u^&
this.countType=countTypes; OFAqP1o{$
} {j=hQL3
public void setCountId(int countIds){ R^O)fL 0_
this.countId=countIds; LAVt/TcZS|
} 2'^OtM,
public String getCountType(){ N4]6LA6x6
return countType; [t=+$pf(-
} ;51!aC
public int getCountId(){ #&8pp8wd,}
return countId; ~i&< !O&
} ToXFMkwY
} fF]&{b~wk
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CountCache.java c"&!=@
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/* !J?=nSu
* CountCache.java OsSiBb,W79
* >`V|`Zi ?
* Created on 2007年1月1日, 下午5:01 _j<M}
* iuk8c.TAR
* To change this template, choose Tools | Options and locate the template under mS;Q8Crh
* the Source Creation and Management node. Right-click the template and choose r_<i*l.
* Open. You can then make changes to the template in the Source Editor. V^5k>`A
*/ OuIW|gIu0
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package com.tot.count; p`.fYW:p
import java.util.*; 2+Y`pz47W
/** iwTBE]J
* BL^Hj
* @author PaI63 !
*/ l#f]KLv4N_
public class CountCache { 9d(v^T
public static LinkedList list=new LinkedList(); <EN[s
/** Creates a new instance of CountCache */ (2(;u1
public CountCache() {} :;u]Y7
public static void add(CountBean cb){ 2<. /HH*f
if(cb!=null){ ;}9Ws6#XQs
list.add(cb); ^p%+r B.j[
} q9z!g/,d/
} zyn =Xv@p
} B-p5;h>
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CountControl.java hfa_M[#Q-
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/* _~&vs<
* CountThread.java {j4:.fD
* w)SxwlW}
* Created on 2007年1月1日, 下午4:57 soK_l|z:J
* \D k^\-
* To change this template, choose Tools | Options and locate the template under =y/Lbe}:
* the Source Creation and Management node. Right-click the template and choose n8D;6#P^
* Open. You can then make changes to the template in the Source Editor. |N.q[>^R
*/ Bq=](<>>
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package com.tot.count; w}<I\*\`!
import tot.db.DBUtils; x(6.W"-S
import java.sql.*; A/6nVn
/** m64\@
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* ]`U?<9~Ob
* @author uXa}<=O
*/ R,Uy3N
public class CountControl{ @!HMd{r
private static long lastExecuteTime=0;//上次更新时间 w|*G`~l09
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ! r\ktX
/** Creates a new instance of CountThread */ wm[d5A4
public CountControl() {} \Le#+P
public synchronized void executeUpdate(){ 0`zq*OQ
Connection conn=null; `,=p\g|D
PreparedStatement ps=null; ?bi^h/f
try{ qiJ;v1
conn = DBUtils.getConnection(); j0NPd^
conn.setAutoCommit(false); I}3K,w/7mi
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); *Z(C')7r
for(int i=0;i<CountCache.list.size();i++){ 9
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CountBean cb=(CountBean)CountCache.list.getFirst(); iEO2Bil]
CountCache.list.removeFirst(); EB<tX`Wp
ps.setInt(1, cb.getCountId()); f3|=T8"t
ps.executeUpdate();⑴ j-\u_#kx%
//ps.addBatch();⑵ 2_DtzY:=
} :#KURYO<
//int [] counts = ps.executeBatch();⑶ }+Z;zm@/6
conn.commit(); ttt&sW`
}catch(Exception e){ &,|uTIs
e.printStackTrace(); 9:5NX3"p
} finally{ UZ0O
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try{ 3+PM_c)Y
if(ps!=null) { OtqLigt&l
ps.clearParameters(); \K=PIcH
ps.close(); {D.0_=y~2
ps=null; 45JLx?rN_
} +@v} (
}catch(SQLException e){} 2xm?,p`
DBUtils.closeConnection(conn); Y0'^S<ox
} #Jb$AA!z
} Mi-9sW
public long getLast(){ +& Qqu`)?F
return lastExecuteTime; @2O\M ,g5
} 6%axbB
public void run(){ K?eo)|4)DB
long now = System.currentTimeMillis(); IMEoov-x
if ((now - lastExecuteTime) > executeSep) { +T;qvx6
//System.out.print("lastExecuteTime:"+lastExecuteTime); ;:1mv
//System.out.print(" now:"+now+"\n"); lK@r?w|<M
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); '*.};t~;"d
lastExecuteTime=now; : P2;9+v
executeUpdate(); ~qxc!k!w4
} t":>O0>cz
else{ +}'K6x_
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); "FD~XSRL
} ^el:)$
} Pk2"\y@q/
} Z)4P>{
//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 NE nP3A
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类写好了,下面是在JSP中如下调用。 2AE|N_v8W
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<% zj4JWUM2
CountBean cb=new CountBean(); sNTfRPC
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); L j\<qF~n
CountCache.add(cb); +fmZ&9hFNJ
out.print(CountCache.list.size()+"<br>"); 4K% YS
CountControl c=new CountControl(); "fwuvT
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c.run(); <VPtbM@(m
out.print(CountCache.list.size()+"<br>"); ,^T2hY`
%>