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: "t+VF4r
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CountBean.java 29g("(}TK
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/* Sd.i1w&
* CountData.java WigC'
* >JFAE5tj&2
* Created on 2007年1月1日, 下午4:44 ^f{+p*i}:
* tvptawA.
* To change this template, choose Tools | Options and locate the template under XljiK8q;%
* the Source Creation and Management node. Right-click the template and choose rUkiwqr~E
* Open. You can then make changes to the template in the Source Editor. Y%$57,Bu n
*/ WlVC0&
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package com.tot.count; AigL:4[
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/** {A4"KX(U
* `LL#Ai a
* @author M_V\mYC8I
*/ M'D;2qo
public class CountBean { c"%XE#D
private String countType; 2.Ym
int countId; hq/k}Y
/** Creates a new instance of CountData */ 7ZHM;_
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public CountBean() {}
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public void setCountType(String countTypes){ $kJvPwRO
this.countType=countTypes; GLA,,i'i9
} !3K6ew>Sf
public void setCountId(int countIds){ OqDLb
this.countId=countIds; x+(h#+F
} Z>Nr"7k
public String getCountType(){ $%VFk 53I
return countType; y";{k+
} pi? q<p%
public int getCountId(){ 8^ ;[c
return countId; )`Tny]M
} .:c^G[CQ^9
} 7|3Z+#|T
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CountCache.java *&>1A A
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/* Oh<[8S7]C
* CountCache.java RNuOwZ1m
* ;Gxp'y
* Created on 2007年1月1日, 下午5:01 >t u3m2
* RX:\@c&
* To change this template, choose Tools | Options and locate the template under kRnh20I
* the Source Creation and Management node. Right-click the template and choose $lci{D32,
* Open. You can then make changes to the template in the Source Editor. 7ZS5u+o
*/ *G$tfb(
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package com.tot.count; M cE$=Vv
import java.util.*; k( 1rp|qf
/** ="3Hc=1?R
* BOn2`|oLuF
* @author [#n~ L6
*/ 2(LS<HqP[
public class CountCache { NFPW#-TF
public static LinkedList list=new LinkedList(); @!^c@
/** Creates a new instance of CountCache */ {AqN@i
public CountCache() {} B[ooT3V
public static void add(CountBean cb){ R>[2}R30
if(cb!=null){ o87. (
list.add(cb); o`\l&jUNe
} ^V v7u@y
} Afo(! v
} |h(!CFR
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CountControl.java #\iQ`Q<B
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/* |vA3+kG
* CountThread.java
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* S0 M-$
* Created on 2007年1月1日, 下午4:57 ^]^Y~$u
* X1!m]s(I
* To change this template, choose Tools | Options and locate the template under dx}()i\@
* the Source Creation and Management node. Right-click the template and choose "jmi
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* Open. You can then make changes to the template in the Source Editor. #
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*/ !NK8_p|X
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package com.tot.count; .Ff;St
import tot.db.DBUtils; XCoN!~
import java.sql.*; R>BI;IcX
/** =El.uBz{
* E}mnGe
* @author 15#v|/wI'
*/ wqyx{W`~w
public class CountControl{ `4}zB#3
private static long lastExecuteTime=0;//上次更新时间 ,*a8]L
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 qS>P,>C
/** Creates a new instance of CountThread */ OF,<K%A
public CountControl() {} 8 wQV^G
public synchronized void executeUpdate(){ [oKc<o7)~"
Connection conn=null; k
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PreparedStatement ps=null; ,d<wEB?\`
try{ /!oi`8D
conn = DBUtils.getConnection(); ${ad[hs
conn.setAutoCommit(false); J %jfuj
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); AnG/A!G
for(int i=0;i<CountCache.list.size();i++){ AF ZHS\
CountBean cb=(CountBean)CountCache.list.getFirst(); ~<Uwumv
CountCache.list.removeFirst(); tx Lo=
ps.setInt(1, cb.getCountId()); KnbT2
ps.executeUpdate();⑴ / _-?NZ
//ps.addBatch();⑵ m*|3
} 2sjV*\Udf
//int [] counts = ps.executeBatch();⑶ 'y}l9alF
conn.commit(); xKEHNgen
}catch(Exception e){ tn+i5Eso
e.printStackTrace(); A5z`_b4f
} finally{ K=M5d^K<E
try{ NtkEb :
if(ps!=null) { .<^dv?@
ps.clearParameters(); l~AmHw
e
ps.close(); ,*?bET
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ps=null; k]`I3>/L
} Sb> ;k(;`:
}catch(SQLException e){} .1.n{4z>:
DBUtils.closeConnection(conn); 0vQ@n7
} fOm=#:O
} &9, 6<bToP
public long getLast(){ {$bAs9L
return lastExecuteTime; (ScL C
} Xgn^)+V:
public void run(){ 5@P2Z]Q
long now = System.currentTimeMillis(); \;I%>yOIu
if ((now - lastExecuteTime) > executeSep) { $dFEC}1t
//System.out.print("lastExecuteTime:"+lastExecuteTime); ?%i|].<-'
//System.out.print(" now:"+now+"\n"); Cd#[b)d ?^
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); FGG Fi(
lastExecuteTime=now; PbJn8o
executeUpdate(); bqFGDmu6'
} 66fvS}x
else{ s[nXr
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ])'22sY
} o?b$}Qrl
} P-ys$=
} -wvrc3F
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 NwIl~FNK
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类写好了,下面是在JSP中如下调用。 VT?JTW
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<% Z9cch-u~
CountBean cb=new CountBean(); @ T'!;)
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Dh BUMDoB
CountCache.add(cb); .8uJ%'$)
out.print(CountCache.list.size()+"<br>"); qS*qHT(u19
CountControl c=new CountControl(); 9(QY~F
c.run(); \'&:6\-fw
out.print(CountCache.list.size()+"<br>"); R#`hT
%>