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: :`zO%h
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CountBean.java P O 5Wi
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/* OcO/wA(&{
* CountData.java ~qj(&[U{c\
* ,c|MB
* Created on 2007年1月1日, 下午4:44 O*GF/ R8B
* !IdVg $7
* To change this template, choose Tools | Options and locate the template under _wK.n.,S~
* the Source Creation and Management node. Right-click the template and choose
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* Open. You can then make changes to the template in the Source Editor. &TBFt;
*/ xws{"m,NX~
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package com.tot.count; c>K]$;}
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/** -
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* F0p=|W
* @author XDJE]2^52?
*/ 6T'UWh0S
public class CountBean { =DJ:LmK
private String countType; 'k[qx}
int countId; ,\iHgsZ
/** Creates a new instance of CountData */ G9^`cTvv'8
public CountBean() {} Z! O4hA4
public void setCountType(String countTypes){ M,_
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this.countType=countTypes; &{.IUg
} Z8ea)_{#
public void setCountId(int countIds){ \hgd&H0UU
this.countId=countIds; P0}{xq'k9v
} 9>w~B|/
public String getCountType(){ 3\@2!:>
return countType; IZj`*M%3
} olv?$]
public int getCountId(){ o& FOp'
return countId; rL1yq|]I
} a%B&F|u
} '~&W'='b;
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CountCache.java 6whPW
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} 7
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/* uL^; i""
* CountCache.java xj;:B( i
* ih".y3
* Created on 2007年1月1日, 下午5:01 ^#<L!yo^
* {\D&*
* To change this template, choose Tools | Options and locate the template under KJ'ID
* the Source Creation and Management node. Right-click the template and choose qx5`lm~L
* Open. You can then make changes to the template in the Source Editor. 'G l~P><e
*/ z1Bi#/i
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package com.tot.count; |qn2b=
import java.util.*; W :]2Tp
/** ]5"k%v|
* t<Yi!6
* @author "jum*<QZz
*/ PiKP.
public class CountCache { o@zxzZWg
public static LinkedList list=new LinkedList(); :TU|:2+
/** Creates a new instance of CountCache */ aNEah
public CountCache() {} z qq
public static void add(CountBean cb){ VQHB}Y@^
if(cb!=null){ vd[7Pxe
list.add(cb); '_G\_h}5
} q k^FyZ<
} I;t@wbY,
} tJ6@Ot
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CountControl.java .@,t}:lD
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/* /%& d:
* CountThread.java dR]-R/1|
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* Created on 2007年1月1日, 下午4:57 T06(Q[)
* Q
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* To change this template, choose Tools | Options and locate the template under (p%|F`
* the Source Creation and Management node. Right-click the template and choose pz
/[${X
* Open. You can then make changes to the template in the Source Editor. z)^|.
*/ 2/*u$~
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package com.tot.count; `xBoNQai
import tot.db.DBUtils; ~|}]
import java.sql.*; ^ f! M"@
/** 9-c3@>v
* 8<C*D".T$
* @author "V>}-G&
*/ %i9 e<.Ot
public class CountControl{ |MZ1j(_
private static long lastExecuteTime=0;//上次更新时间 T ?[28|
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 1 jidBzu<
/** Creates a new instance of CountThread */ BI`)P+K2
public CountControl() {} C>+n>bH]L
public synchronized void executeUpdate(){ ,~d0R4)
Connection conn=null; N@c GjpQ
PreparedStatement ps=null; +-<G(^
try{ <}RI<96
conn = DBUtils.getConnection(); n>ui'}L
conn.setAutoCommit(false); TF/NA\0c$
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); U*r54AyP
for(int i=0;i<CountCache.list.size();i++){ }pMVl
CountBean cb=(CountBean)CountCache.list.getFirst(); VC88re`
CountCache.list.removeFirst(); $z%(He
ps.setInt(1, cb.getCountId()); >)ekb7
ps.executeUpdate();⑴ q~R8<G%YK
//ps.addBatch();⑵ OS,!`8cw
} *<xu3){:c
//int [] counts = ps.executeBatch();⑶ uslu-|b!%
conn.commit(); "@nH;Xlq
}catch(Exception e){ 4?+K
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e.printStackTrace(); l/G+Xj4M
} finally{ dxs5woP
try{ %VO+\L8Fs
if(ps!=null) { 'Bue*
ps.clearParameters(); h:8P9WhWF
ps.close(); +06{5-,
ps=null; <YU?1y?V
} ^L2d%d\5
}catch(SQLException e){} Hx gC*-A$/
DBUtils.closeConnection(conn); s6|'s<x"j
}
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} ~b~Tq
public long getLast(){ j9h/`Bn
return lastExecuteTime; 0DicrnH8
} d{7ZO#E
public void run(){ "] V\ Y!
long now = System.currentTimeMillis(); {cs>Sy
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if ((now - lastExecuteTime) > executeSep) { M~2Us{ `
//System.out.print("lastExecuteTime:"+lastExecuteTime); kg^0 %-F
//System.out.print(" now:"+now+"\n"); h vYRAQR:
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); .2E/(VM
lastExecuteTime=now; 0zH-g
executeUpdate(); R2Tt6
} ^!\1q<@n
else{ #"UO`2~`l
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); wG,"X'1
} H@uu;:l<7A
} x2B8G;6u
} `}?;Ow&2CY
//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 QOXo(S
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类写好了,下面是在JSP中如下调用。 Lm4`O%
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<% +|LM"
CountBean cb=new CountBean(); 5C!zEI)
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); }%u#TwZ
CountCache.add(cb); D -tRy~}
out.print(CountCache.list.size()+"<br>"); K+}0:W=P
CountControl c=new CountControl(); V~dhTdQ5}
c.run(); [q?RJmB]
out.print(CountCache.list.size()+"<br>"); &4-;;h\H
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