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: SE@TY32T
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CountBean.java F kf4R5Y?
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/* &FT`z"^
* CountData.java D15-pz|Q
* u a_w5o7
* Created on 2007年1月1日, 下午4:44 g\@ .qKF
* S.1>bs2
* To change this template, choose Tools | Options and locate the template under ztX$kX:_m
* the Source Creation and Management node. Right-click the template and choose ;v2eAe@7
* Open. You can then make changes to the template in the Source Editor. 0)~c)B:5
*/ x9a\~XL>a
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package com.tot.count; knph549
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/** rxyeix
* t8h*SHD9
* @author -T{2R:\{
*/ B@i%B+qCLv
public class CountBean { "-dA\,G
private String countType; Zl3e=sg=
int countId; ~yw]<{ ?
/** Creates a new instance of CountData */ ~LV]cX2J(
public CountBean() {} HF_8661g
public void setCountType(String countTypes){ Q~svtN
this.countType=countTypes; 1E&S{.
} eL(<p]
public void setCountId(int countIds){ GN!
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this.countId=countIds; L3xN#W;m7
} *.k*JsU~B
public String getCountType(){ 2y;vX|lX]
return countType; ~&qv[XS
} /_{ZWLi(
public int getCountId(){ KA?%1s(kJ
return countId; sCrP+K0D
} OW\vbWX
} at@tS>Dv
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CountCache.java &?H$-r1/?V
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/* BSgT
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* CountCache.java 7g+T
* 42"nbJ
* Created on 2007年1月1日, 下午5:01 QkD
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* 6Z J-oT!.
* To change this template, choose Tools | Options and locate the template under 7kE+9HmfMk
* the Source Creation and Management node. Right-click the template and choose j7gTVfO
* Open. You can then make changes to the template in the Source Editor. >A-{/"p#
*/ )?(Ux1:w)
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package com.tot.count; /NCN wAj7
import java.util.*; GPhhg
/** p!^K.P1 '
* 8zj&e8&v
* @author U), HrI>;
*/ qmFbq<&
public class CountCache { rM
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public static LinkedList list=new LinkedList(); C`kqsK
/** Creates a new instance of CountCache */ ~//E'V-
public CountCache() {} MQN~I^v3
public static void add(CountBean cb){
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if(cb!=null){ \X%FM"r
list.add(cb); tm=,x~
} *9kg\#
} Z Se30Rl\
} ov,s]g83
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CountControl.java *#Ia8^z=p
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/* n~|?)EL
* CountThread.java ki@C}T5
* H8? Y{H
* Created on 2007年1月1日, 下午4:57 xp95KxHHo
* .Hqq!&
* To change this template, choose Tools | Options and locate the template under 5=
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* the Source Creation and Management node. Right-click the template and choose Y8v[kuo7
* Open. You can then make changes to the template in the Source Editor. xlwf @XW
*/ T:{r*zLSN
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package com.tot.count; (P-^ PNz&
import tot.db.DBUtils; 'hBnV xd&
import java.sql.*; !JrKTB%
/** M`'DD-Q
* 8Z9>h:c1
* @author ez[x8M>
*/ {._'Q[
public class CountControl{ _%D7D~2r|
private static long lastExecuteTime=0;//上次更新时间 "%^_.Db>|
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 [[AO6.Z
/** Creates a new instance of CountThread */ B47 I?~{
public CountControl() {} #vyf*jPr
public synchronized void executeUpdate(){ cw
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Connection conn=null; 8YlZ({f
PreparedStatement ps=null; HOWpTu(
try{ Fovah4q%V
conn = DBUtils.getConnection(); %?gG-R
conn.setAutoCommit(false); a"U3h[;$y
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); -sJD:G,%
for(int i=0;i<CountCache.list.size();i++){ H<i!C|AF
CountBean cb=(CountBean)CountCache.list.getFirst(); E:**gvfq
CountCache.list.removeFirst(); 8o%Vn'^t
ps.setInt(1, cb.getCountId()); {X(nn.GpC
ps.executeUpdate();⑴ @#,/6s7?
//ps.addBatch();⑵ FD
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} g&2g>]
//int [] counts = ps.executeBatch();⑶ ?|W3RK;
conn.commit(); Bt@?l]Y
}catch(Exception e){ zc)nDyn
e.printStackTrace(); E#(e2Z=
} finally{ 4uoZw3O
try{ O5p$
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if(ps!=null) { ~s HdOMw
ps.clearParameters(); b=MW;]F
ps.close(); kGAgXtE
ps=null; 0O`Rh"O
} d>)=|
}catch(SQLException e){} ZXYyG`3+
DBUtils.closeConnection(conn); T=42]h
} SQf[1}$ .
} !vu-`u~86
public long getLast(){ Kj
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return lastExecuteTime; Oz-/0;1n
} g*oX`K.
public void run(){ iEtR<R>=
long now = System.currentTimeMillis(); ^z)De+,!4
if ((now - lastExecuteTime) > executeSep) { v\?J=|S+
//System.out.print("lastExecuteTime:"+lastExecuteTime); ~v2(sRJ
//System.out.print(" now:"+now+"\n"); Ep./->fOA
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); #?S"y:
lastExecuteTime=now; A~vx,|I
executeUpdate(); e Fz$h2*B
} 4_QfM}Fyp
else{ t.;._'
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); =T2SJ)
} 9;7"S.7AV
} @B>D>B
} 7_s+7x =
//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 S5>ztK.e
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类写好了,下面是在JSP中如下调用。 X+A@//,7
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<% oZY|o0/9
CountBean cb=new CountBean(); A? B+
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); +0%r@hTv&>
CountCache.add(cb); 56s%Qlgx
out.print(CountCache.list.size()+"<br>"); klQmo30i
CountControl c=new CountControl(); +:jonN9d
c.run(); >uYQt~s
out.print(CountCache.list.size()+"<br>"); 8493Sw
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