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: VmM?KlC
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CountBean.java P#5&D*`}h
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/* M&Aeh8>uX
* CountData.java $i&u\iL
* epa)~/sA
* Created on 2007年1月1日, 下午4:44 |T: 'G
* e1ru#'z
* To change this template, choose Tools | Options and locate the template under >gqM|-uY
* the Source Creation and Management node. Right-click the template and choose MM8r*T4g/
* Open. You can then make changes to the template in the Source Editor. 7Pu.<b}
*/ ,B]kX/W
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package com.tot.count; u!TVvc
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/** Q C?*O?~#
* 2aiZ
* @author >D'Kt?L<]m
*/ _h1n]@
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public class CountBean { Q%6Lc.i
private String countType; B\BxF6 y
int countId; CCp&P5[67
/** Creates a new instance of CountData */ _:4n&1{.E
public CountBean() {} wmh[yYWc
public void setCountType(String countTypes){ <t[WHDO`
this.countType=countTypes; _l}"gUti w
} 6@_Vg~=S
public void setCountId(int countIds){ e>W}3H5w0
this.countId=countIds; \Q[u ?/TF
} dQ+{Dv3A
public String getCountType(){ z>HeM
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return countType; alM
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} (~t/8!7N
public int getCountId(){ 7U_~_yb
return countId; 8':^tMd
} .<8kDyim
} J}IHQZS
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CountCache.java PfKIaW<
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/* PS ,@ \
* CountCache.java nY7
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* Aa^%_5
* Created on 2007年1月1日, 下午5:01 tjw4.L<r
* }r`m(z$z
* To change this template, choose Tools | Options and locate the template under ;Js-27_0
* the Source Creation and Management node. Right-click the template and choose J)R;NYl
* Open. You can then make changes to the template in the Source Editor. jcNYW_G
*/ 8RC7Ei
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package com.tot.count; 5e^t;
import java.util.*; \OMWE/qMy
/** A*)G. o:
* MpZ
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* @author f=%k9Y*)
*/ +D
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public class CountCache { hiKgV|ZD
public static LinkedList list=new LinkedList(); R~nbJx$
/** Creates a new instance of CountCache */ "p<B|
public CountCache() {} %hcn|-"F
public static void add(CountBean cb){ iXl6XwWT%8
if(cb!=null){ A1{ 7g<k6
list.add(cb); 8 /3`rEW
} |q&&"SpA
} x^_(gve:
} . e' vc
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CountControl.java HFV4S]U=
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/* [gK (x%
* CountThread.java ZMs$C3
* 7aAT
* Created on 2007年1月1日, 下午4:57 hdZ{8 rP
* FGzMbi<l#(
* To change this template, choose Tools | Options and locate the template under L`>uO1O
* the Source Creation and Management node. Right-click the template and choose .GG6wL<$?
* Open. You can then make changes to the template in the Source Editor. *aKT&5Ch-
*/ o&tETJ5Bhe
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package com.tot.count; [~cb&6|M
import tot.db.DBUtils; ^{L/) Xy5
import java.sql.*; 3<:(Eda}
/** 7g'jg7
* ,9T-\)sT
* @author m0XdIC]s
*/ JO\F-xO
public class CountControl{ u,]?_bK)
private static long lastExecuteTime=0;//上次更新时间 F'eV%g
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 G&P[n8Z$
/** Creates a new instance of CountThread */ =pQ'wx|>|
public CountControl() {} Uy8r
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public synchronized void executeUpdate(){ {FV_APL9_
Connection conn=null; Ja$Ple*XU8
PreparedStatement ps=null; k%UE^
try{ ]xhZJ~"@u
conn = DBUtils.getConnection();
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conn.setAutoCommit(false); TFrZ+CcWp2
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); MfzSoxCb
for(int i=0;i<CountCache.list.size();i++){ ivy+e-)
CountBean cb=(CountBean)CountCache.list.getFirst(); _T,X z_
CountCache.list.removeFirst(); udCum4
ps.setInt(1, cb.getCountId()); P.G`ED|K!Y
ps.executeUpdate();⑴ ,Mt/*^|
//ps.addBatch();⑵ ~zEBJgeyh
} x8L$T (^
//int [] counts = ps.executeBatch();⑶ ~`7L\'fs
conn.commit(); FT0HU<." 1
}catch(Exception e){ rnB-e?>
e.printStackTrace(); DEmU},<S
} finally{ {<\ [gm\X
try{ lPA:aHcj
if(ps!=null) { 9
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ps.clearParameters(); wWaO"N]
ps.close(); %!_okf
ps=null; mGf@J6wGz
} Z_Tu*
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}catch(SQLException e){} $9_yD&&
DBUtils.closeConnection(conn); \\\%pBT7]\
} 3v oas
} La$*)qD,
public long getLast(){ Fu@2gd
return lastExecuteTime; y]dA<d?u
} 37j-FLbW
public void run(){ =&kd|o/i
long now = System.currentTimeMillis(); N~<H`
if ((now - lastExecuteTime) > executeSep) { gpo+-NnG
//System.out.print("lastExecuteTime:"+lastExecuteTime); hrLPyV:
//System.out.print(" now:"+now+"\n"); 5.1 c#rL
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); zUw=e}?:
lastExecuteTime=now; RtE2%d$JT
executeUpdate(); !F@9xG
} ^o`;C\
else{ )FF3|dZ";K
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); *)+K+J
} L.5 /wg
} pA
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} ^ Tr )gik
//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 g\Ck!KJ/y
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类写好了,下面是在JSP中如下调用。 Gw\-e;,
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<% ukZ>_ke`+
CountBean cb=new CountBean(); $)V_oQSqn
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ]VarO'
CountCache.add(cb); 2swHJ.d\
out.print(CountCache.list.size()+"<br>"); !|SVRaS
CountControl c=new CountControl(); Rds_Cd C
c.run(); [;rty<Z^b
out.print(CountCache.list.size()+"<br>"); /FP;Hsw%
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