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: L|DSEth
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CountBean.java aOYRenqu
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/* l\l\T<wa,
* CountData.java !/0XoIf"
* 2fc8w3
* Created on 2007年1月1日, 下午4:44 Ugmg,~U~k
* /wIev1Z!Y
* To change this template, choose Tools | Options and locate the template under 1KxtHLLU
* the Source Creation and Management node. Right-click the template and choose h~$Q\WCm#
* Open. You can then make changes to the template in the Source Editor. %v++AcE
*/ GiBq1U-Q
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package com.tot.count; 6ju+#]T
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/** 8;3T65KY
* qIQvix$8
* @author VHsNz WI
*/ DBi3 j
public class CountBean { ;(3fr0cr:
private String countType; h+$1+Es
int countId; /Ny/%[cu
/** Creates a new instance of CountData */ 2S^xqvh
public CountBean() {} 6USet`#
public void setCountType(String countTypes){ n?@o:c5,r
this.countType=countTypes; .a:Oj3=0
} k}-%NkQ
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public void setCountId(int countIds){ <PkDfMx2
this.countId=countIds; gDnG!i+
} &G55<tRE
public String getCountType(){ avls[Bq
return countType; %@(6,^3%i
} Jg|3Wjq5
public int getCountId(){ <u44YvLBm
return countId; Cg
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} =1n>vUW+J
} Bd m<<<
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CountCache.java 6"
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/* /S9Mu
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* CountCache.java > ^3xBI:Q
* 7w)#[^
* Created on 2007年1月1日, 下午5:01 B7t#H?
* ?Z!itB~
* To change this template, choose Tools | Options and locate the template under D]b5*_CT
* the Source Creation and Management node. Right-click the template and choose pM[UC{
* Open. You can then make changes to the template in the Source Editor. O\OG~`HBN
*/ wlKpHd*
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package com.tot.count; ~"EkX
import java.util.*; x#dJH9NR[
/** I+O!<SB
* 7"4|`y^#
* @author UDyvTfh1X
*/ !l6B_[!@
public class CountCache { :'GTCo$3
public static LinkedList list=new LinkedList(); ]2zx}D4f
/** Creates a new instance of CountCache */ N!RyncJ
public CountCache() {} %XG X(
public static void add(CountBean cb){ 5
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if(cb!=null){ RWTv,pLK
list.add(cb); pSq\3Hp]Q
} s'\"%~nF<
}
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} :Np&G4IM>
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CountControl.java 3CQpe
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/* W,Dr2$V
* CountThread.java (a7IxW
* %I Y-0\
* Created on 2007年1月1日, 下午4:57 |Z 3POD"9
* f.+e
* To change this template, choose Tools | Options and locate the template under NV9= ~cx
* the Source Creation and Management node. Right-click the template and choose Y]8l]l 1
* Open. You can then make changes to the template in the Source Editor. d2X#_(+d
*/ _,Fwt
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package com.tot.count; , is
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import tot.db.DBUtils; o]Vx6
import java.sql.*; ` S85i*
/** 9@D,ZSi
* zP=J5qOZ8
* @author ,u]kZ ]
*/ }
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public class CountControl{ 5QmF0z)wR
private static long lastExecuteTime=0;//上次更新时间 /.WD'*H
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 a+]=3o
/** Creates a new instance of CountThread */ iQa Q"s
public CountControl() {} l^0
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public synchronized void executeUpdate(){ yY_]YeeR
Connection conn=null; lBh {8a|2W
PreparedStatement ps=null; W=)}=^N0
try{ t]vX9vv+D
conn = DBUtils.getConnection(); 9pjk3a
conn.setAutoCommit(false); >656if O
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); s
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for(int i=0;i<CountCache.list.size();i++){ dd4yS}yBlR
CountBean cb=(CountBean)CountCache.list.getFirst(); o~GhV4vq
CountCache.list.removeFirst(); F1Z20)8K
ps.setInt(1, cb.getCountId()); $<33E e:a
ps.executeUpdate();⑴ XTeU2I
//ps.addBatch();⑵ i1G}mYz_
} _r,# l5~U
//int [] counts = ps.executeBatch();⑶ 4L5Wa~5\
conn.commit(); T@Q.m.iV4
}catch(Exception e){ }){hQt7
e.printStackTrace(); , H[o.r=
} finally{ $\P!P.
try{ 9Xm"kVqd/
if(ps!=null) { MCYrsgg}
ps.clearParameters(); Za01z^
ps.close(); a<\m`
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ps=null; O9>/WmLe
} fwl
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}catch(SQLException e){} j
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DBUtils.closeConnection(conn); fk",YtS*
} `,7BU??+u
} St(7@)gvY
public long getLast(){ x3M`l|
return lastExecuteTime; v.Q)Obyn
} /Hd\VI
public void run(){ >)VrbPRuA
long now = System.currentTimeMillis(); ="I]D
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if ((now - lastExecuteTime) > executeSep) { 52%.^/
//System.out.print("lastExecuteTime:"+lastExecuteTime); (,<?Pg7v:f
//System.out.print(" now:"+now+"\n"); Crey}A/N
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Wxg|jP$~
lastExecuteTime=now; .Wa6?r<g
executeUpdate(); S*\`LBl"nX
} 12rr:(#%s
else{ _ :][{W#
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); #U6Wv1H{Lp
} fd)}I23Q'
} :z^c<KFX
} G-;pMFP(?
//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 l[h??C`
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类写好了,下面是在JSP中如下调用。 z1YC%Y|R
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<% $aVcWz%
CountBean cb=new CountBean(); M\T6cN@m
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); oFY'Ek;d
CountCache.add(cb); wRWN]Vo
out.print(CountCache.list.size()+"<br>"); ]i{-@Ven
CountControl c=new CountControl(); t/y0gr tm6
c.run(); 58=fT1
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out.print(CountCache.list.size()+"<br>"); CaK 0o*D
%>