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: bAL!l\&2
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CountBean.java p"q4R2_/jh
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/* `BY&&Bv#?
* CountData.java &uxwz@RC0
* Mh5 =]O+
* Created on 2007年1月1日, 下午4:44 xJ)vfo
* R1\$}ep^
* To change this template, choose Tools | Options and locate the template under -42jeJS
* the Source Creation and Management node. Right-click the template and choose 6n'XRfQp)&
* Open. You can then make changes to the template in the Source Editor. fg8U*7
*/ #VM-\02o
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package com.tot.count; Sv03="&
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/** l}mzCIw%
* z_en.
* @author lof}isOz
*/ & ^JY
public class CountBean { u9) <i]2
private String countType; ]}jY]
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int countId; @W*Zrc1NF
/** Creates a new instance of CountData */ ;Z}V}B
public CountBean() {} qEB]Tj e[
public void setCountType(String countTypes){ /,2${$c!
this.countType=countTypes; }\_[+@*EJ
} ){XG%nC
public void setCountId(int countIds){ xnG,1doa
this.countId=countIds; 3}X; WE `
} w7X], auRC
public String getCountType(){ +#R<emW
return countType; Y7
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} $5a%hK
public int getCountId(){ 7eekTh, ?
return countId; [l X3":)
} -(+/u .
} 7=x]p
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CountCache.java cakb.Q
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/* \%N |
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* CountCache.java p*Hbc|?{Q&
* PEX(*GS
* Created on 2007年1月1日, 下午5:01 c`h/x>fa
* C/x<_VJzN/
* To change this template, choose Tools | Options and locate the template under x?MSHOia`P
* the Source Creation and Management node. Right-click the template and choose sz%'=J~!V
* Open. You can then make changes to the template in the Source Editor. Mlr}v^"G
*/ -g]g
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package com.tot.count; R2$;f?;:
import java.util.*; f6Io|CZWJ
/** B?)=d,E
* FGG7;0(
* @author v(2|n}qY
*/ |,Xrt8O/[
public class CountCache { _o-D},f*e
public static LinkedList list=new LinkedList(); 1f^4J~{
/** Creates a new instance of CountCache */ C) "|sG
public CountCache() {} 53cW`F
public static void add(CountBean cb){ B!cg)Y?.bd
if(cb!=null){ -(fvb
list.add(cb); QR;E>eEq
} 'Nbae-pf
} X#*|_(^
} ;n,@[v
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CountControl.java RZeU{u<O
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/* uM9[
* CountThread.java jTJ]: EN
* Z;#Ei.7p|
* Created on 2007年1月1日, 下午4:57 .<C}/Cl
* :LwNOuavN
* To change this template, choose Tools | Options and locate the template under h[0,/`qb{
* the Source Creation and Management node. Right-click the template and choose :5`BhFAd
* Open. You can then make changes to the template in the Source Editor. l[q%1-N
*/ $Z;?d@6yI
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package com.tot.count; R1DXi
import tot.db.DBUtils; U{2UKD@PM
import java.sql.*; oG )JH)!
/** w3=Bj
* }#/,nJm'
* @author v"6ijk&(
*/ <([1(SY2e
public class CountControl{ .iB?:
private static long lastExecuteTime=0;//上次更新时间 .V?i 3
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 m1k+u)7kD
/** Creates a new instance of CountThread */ FV&&
public CountControl() {} 8U07]=Bt<
public synchronized void executeUpdate(){ + fQ=G/
Connection conn=null; ddMSiwbY)
PreparedStatement ps=null; {1y-*@yU(
try{ "gD)Uis
conn = DBUtils.getConnection(); a
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conn.setAutoCommit(false); :>.~"uWo{
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); qxsK-8KT<
for(int i=0;i<CountCache.list.size();i++){ =_`4HDr
CountBean cb=(CountBean)CountCache.list.getFirst(); 0~\Dd0W/:`
CountCache.list.removeFirst(); 8S>T1st
ps.setInt(1, cb.getCountId()); |"Js iT
ps.executeUpdate();⑴ + (cTzY
//ps.addBatch();⑵ &r6VF/
} ~ (xIG
//int [] counts = ps.executeBatch();⑶ c D+IMlT
conn.commit(); Mlp[xk|
}catch(Exception e){ MEQ:[;1
e.printStackTrace(); XQu~/{A=
} finally{ fL8+J]6A6
try{ mACj>0Z'
if(ps!=null) { uhFj|r$$
ps.clearParameters(); szC~?]<YY
ps.close(); N.|Zh+!
ps=null; s fxQ
} <aR8fU
}catch(SQLException e){} ;K:)R_H
DBUtils.closeConnection(conn); >Rw[ x
} f!~gfnn
} =>Vo|LBoe
public long getLast(){ &P%3'c}G
return lastExecuteTime; vv
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} Ch`XwLY9
public void run(){ ;(Q4x"?I
long now = System.currentTimeMillis(); 6=kA
if ((now - lastExecuteTime) > executeSep) { 5A:mu+Iz6H
//System.out.print("lastExecuteTime:"+lastExecuteTime); 8VJUaL@
//System.out.print(" now:"+now+"\n"); xV'\2n=1T
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); lK%pxqx
lastExecuteTime=now; }Lx?RU+@=
executeUpdate(); J 21D/#v
} |\j'Z0
else{ j(!M
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 2B7X~t>8a
} xn&G`
} >_1*/o
JO
} zxtx~XO
//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 2;G^>BP<
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类写好了,下面是在JSP中如下调用。 DKCPi 0
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<% 8?4j-
CountBean cb=new CountBean(); I)AV
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 0(;d<u)fS
CountCache.add(cb); NamBJ\2E1[
out.print(CountCache.list.size()+"<br>"); &inu mc
CountControl c=new CountControl(); 8H3|i7.1h
c.run(); -DrR6kGjR
out.print(CountCache.list.size()+"<br>"); x-k}RI
%>