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: =g)SZK
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CountBean.java JQSczE3
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/* O*9d[jw[
* CountData.java IW=%2n(<1
* "Jg*
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* Created on 2007年1月1日, 下午4:44 d V3R)
* T5aeO^x
* To change this template, choose Tools | Options and locate the template under )_K:A(V>
* the Source Creation and Management node. Right-click the template and choose X`7O%HiX/`
* Open. You can then make changes to the template in the Source Editor. Hm_&``='
*/ =j8g6# 'u
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package com.tot.count; ,9W!cD+0
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/** *s!T$oc
* +Rq]_sDu
* @author Xliw(B'\a4
*/ u9{Z*w3L7
public class CountBean { 2Iq*7n:v0
private String countType; =64Ju Wvo
int countId; avd`7eH2
/** Creates a new instance of CountData */ `LJ.NY pP
public CountBean() {} !~]'&9
public void setCountType(String countTypes){ _J0(GuG=~
this.countType=countTypes; ^NrC8,p
} F "-GhjK
public void setCountId(int countIds){ o6 8;-b'n
this.countId=countIds; \ZC0bHsA
} hho\e
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public String getCountType(){ 7+m.:~H3}
return countType; FeJKXYbk<
} ^;;gPhhWV
public int getCountId(){ Xnxb.{C
return countId; G4"[ynlWV
} uC"Gm;0
} 8e_9u@p+w
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CountCache.java <'O|7.
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/* >x${I`2w
* CountCache.java d4LH`@SUZ-
* _p%@x:\
* Created on 2007年1月1日, 下午5:01 -V:7j8
* 2MDY nMy
* To change this template, choose Tools | Options and locate the template under `%=!_|
* the Source Creation and Management node. Right-click the template and choose
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* Open. You can then make changes to the template in the Source Editor. 0~cbB
*/ }QJ6"s
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package com.tot.count; D#11
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import java.util.*; B{NGrC`5)
/** 78E<_UgcB
* l6T5]$
* @author ?8$h%Ov-
*/ .7n`]S/
public class CountCache { P,7beHjf
public static LinkedList list=new LinkedList(); n ZzGak
/** Creates a new instance of CountCache */ =]0AZ
public CountCache() {} f:h<tlob
public static void add(CountBean cb){ !3Q^oR
if(cb!=null){ 2bTM0-
list.add(cb); 3NrWt2?
} oTf^-29d
} |]OI)w*
} z_87;y;=
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CountControl.java 0lpUn74F
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/* yu=(m~KX
* CountThread.java f6%7:B d
* )IGx3+I
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* Created on 2007年1月1日, 下午4:57 S{JBV@@tC
* -nk0Q_7N
* To change this template, choose Tools | Options and locate the template under Og"\@n
* the Source Creation and Management node. Right-click the template and choose :JzJ(q/
* Open. You can then make changes to the template in the Source Editor. ''B}^yKEW
*/ kDWvjT
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package com.tot.count; ,/..f!bp
import tot.db.DBUtils; X1GM\*BE
import java.sql.*; v;IuB
/** >\>!Q V1@
* k
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* @author RGLi#:0_.x
*/ ,kE"M1W
public class CountControl{ CDWchY
private static long lastExecuteTime=0;//上次更新时间 ;V4f6[<]'z
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 s6_[H
/** Creates a new instance of CountThread */ E=l^&[dIl
public CountControl() {} LZApz}
public synchronized void executeUpdate(){ "@@Z{
Connection conn=null; +<n8O~h
PreparedStatement ps=null; pv,I_"
try{ Dqm;twd>
conn = DBUtils.getConnection(); >Q|S#(c
conn.setAutoCommit(false); =%9j8wHX
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ]D|Hq4ug
for(int i=0;i<CountCache.list.size();i++){ N"2P]Zr
CountBean cb=(CountBean)CountCache.list.getFirst(); 3 ~\S]
CountCache.list.removeFirst(); `6y\.6j
ps.setInt(1, cb.getCountId()); axdRV1+s
ps.executeUpdate();⑴ [2nPr^
//ps.addBatch();⑵ (J`EC
} *@[+C~U
//int [] counts = ps.executeBatch();⑶ 6q~*\KRk
conn.commit(); /w:~!3Aj0+
}catch(Exception e){ a9TKp$LP`
e.printStackTrace(); Eb9{
} finally{ hB-<GGcO <
try{ M}`G}*
if(ps!=null) { b "5WsJ:'#
ps.clearParameters(); `Qo}4nuRs
ps.close(); 4AuJ1Z
ps=null; <k-hRs2d
} W>rx:O+
}catch(SQLException e){} U,GY']J
DBUtils.closeConnection(conn); |BA<> WE
} >y
iE}
} =s1Pf__<k
public long getLast(){ X1Y+ao 1)
return lastExecuteTime; `i3fC&?C
} 5gY9D!;:0D
public void run(){ O@? *5
long now = System.currentTimeMillis(); - x]gp5
if ((now - lastExecuteTime) > executeSep) { JbEQ35r
//System.out.print("lastExecuteTime:"+lastExecuteTime); is}Y+^j.
//System.out.print(" now:"+now+"\n"); T>pz?e^5&
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); !<j)D_
lastExecuteTime=now; '1Q [&
executeUpdate(); =bB7$#al
} /&G )IY]g
else{ Fx' E"d
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); g+M& _n
} ,SSq4
} /S&8%fb
} K!_''Fg
//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 "\1QJ
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类写好了,下面是在JSP中如下调用。 t+Hx&_pMj
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<% m6M:l"u
CountBean cb=new CountBean(); {-)*.l=
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); x>~.cey
CountCache.add(cb); =CjN=FM
out.print(CountCache.list.size()+"<br>"); nwPU{4#l<
CountControl c=new CountControl(); UvM_~qo
c.run(); q.NvwJ
out.print(CountCache.list.size()+"<br>"); ,N`D{H"F
%>