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: %w/:mH3FA
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CountBean.java [Ue"#w
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/* @Y&(1Wl
* CountData.java wF['oUwHH
* $\nAGmp@
* Created on 2007年1月1日, 下午4:44 \!r,>P
* c 9zMI
* To change this template, choose Tools | Options and locate the template under k3e?:t 9
* the Source Creation and Management node. Right-click the template and choose 1tCe#*|95
* Open. You can then make changes to the template in the Source Editor. nqib`U@"
*/ ~_4$|WKl
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package com.tot.count; MrS~u
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/** {
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* ;J?zD9
* @author mS-{AK
*/ 1jj.oa]
public class CountBean { R"JT+m
private String countType; (V8lmp-F
int countId; {F*81q\
/** Creates a new instance of CountData */ Q$^Kf]pD
public CountBean() {} fq[,9lK
public void setCountType(String countTypes){ 9Jf.Ls
this.countType=countTypes; <\5E{/7Tl
} "3uPK$
public void setCountId(int countIds){ t1]svVX,w
this.countId=countIds; ?Ns aZ
} PZCOJK
public String getCountType(){ T_4y;mf!@O
return countType; )Yw m_f-N
} .RWKZB
public int getCountId(){ |z.Z='`
return countId; :*E#w"$,j
} koOp:7r
} 7|pF(sb0
jb!15Vlt"
CountCache.java @ u2P&|:{
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/* !XrnD#
* CountCache.java w 8oIq*
* L
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* Created on 2007年1月1日, 下午5:01 ;rJ/Diz!g
* ZS?4<lXF
* To change this template, choose Tools | Options and locate the template under +Zi@+|"BCN
* the Source Creation and Management node. Right-click the template and choose $pYT#_P!/
* Open. You can then make changes to the template in the Source Editor. '0E^th#u-0
*/ /Es&~Fn
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package com.tot.count; ;{Su:Ixg
import java.util.*; vip&
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/** vKcc|#
* /-&a]PJ
* @author 1
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*/ ~z*A%vp6ER
public class CountCache { TmO3hKaP
public static LinkedList list=new LinkedList(); t(.xEl;Ma
/** Creates a new instance of CountCache */ sRf?JyB
public CountCache() {} _6&TCd<
public static void add(CountBean cb){ 9A9yZl t
if(cb!=null){ Q.])En >i
list.add(cb); ~;B@ {kFY)
} '/H+
} b:>t1S Ul
} d"hW45L
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CountControl.java 9..! g:
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/* j= Ebk;6p
* CountThread.java A@k`$xevVj
* N\WEp?%~
* Created on 2007年1月1日, 下午4:57 j?cE0
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* |c5r&oM&m
* To change this template, choose Tools | Options and locate the template under ;bxL$1
* the Source Creation and Management node. Right-click the template and choose 8X2NEVH]
* Open. You can then make changes to the template in the Source Editor. _^"0"<,
*/ h(wu5G0C#u
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package com.tot.count; d#]XyN>
import tot.db.DBUtils; 9Fv VM9
import java.sql.*; lDm0O)Dh!
/** SLMnEtyTS
* Hwm]l`E]
* @author mtg3}etA
*/ A +J&(7N
public class CountControl{ ` p)$7!
private static long lastExecuteTime=0;//上次更新时间 G^=C#9c.m
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 | ?])]F
/** Creates a new instance of CountThread */ CHX- 4-84{
public CountControl() {} j6{9XIRo_
public synchronized void executeUpdate(){ :")iS?l
Connection conn=null; 4!
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PreparedStatement ps=null; f)/5%W7n}
try{ =]yzy:~ey
conn = DBUtils.getConnection(); 'WLh
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conn.setAutoCommit(false); GH!Lu\y\
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); EvEI5/z
for(int i=0;i<CountCache.list.size();i++){
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CountBean cb=(CountBean)CountCache.list.getFirst(); Qt+;b
CountCache.list.removeFirst(); XrD@q
ps.setInt(1, cb.getCountId()); c O[Hr
ps.executeUpdate();⑴ .gK>O2hI
//ps.addBatch();⑵ S;]][h=
} BVk&TGa;[$
//int [] counts = ps.executeBatch();⑶ yG<`7v
conn.commit(); /MUa
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}catch(Exception e){ vuE 1(CR
e.printStackTrace(); U4hFPK<
} finally{ +Tug.[A
try{ pN
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if(ps!=null) { pAd 8-a
ps.clearParameters(); #.kDin~!
ps.close(); )$_b?
ps=null; u= u#6%
} _9Zwg+oO[
}catch(SQLException e){} eURj'8o),
DBUtils.closeConnection(conn); :_y}8am;H~
} CVyE5w
} vw/L|b7G
public long getLast(){ [Q5>4WY
return lastExecuteTime; tEXY>=
} 3Bk_4n
public void run(){ FV->226o%
long now = System.currentTimeMillis(); #nOS7Q#uW
if ((now - lastExecuteTime) > executeSep) { SZ[,(h
//System.out.print("lastExecuteTime:"+lastExecuteTime); Fs,#d%4 @%
//System.out.print(" now:"+now+"\n"); ?UGA-^E1
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); bdUe,2Yi n
lastExecuteTime=now; VS{po:]A
executeUpdate(); .+ w#n<
} |6d0,muN
else{ R;68C6 4
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); U:n3V
} KPcOW#.T
} A=S_5y
} @!UuK;
//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 ]a}K%D)H
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类写好了,下面是在JSP中如下调用。 IY='tw
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<% Fuuy_+p@G
CountBean cb=new CountBean(); Ur/+nL{
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); @{|vW
CountCache.add(cb); lSu\VCG
out.print(CountCache.list.size()+"<br>"); B]o5HA<k
CountControl c=new CountControl(); 2#y!(D8
c.run(); "DniDA
out.print(CountCache.list.size()+"<br>"); <FfdOK_
%>