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: 7@W>E;go
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CountBean.java f3y=Wxk[
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/* |2A:eI8 ^
* CountData.java SOIN']L|V[
* do'GlU oMC
* Created on 2007年1月1日, 下午4:44 'LDQgC*%
* \s\?l(ooq"
* To change this template, choose Tools | Options and locate the template under wUJcmM;
* the Source Creation and Management node. Right-click the template and choose P]C<U aW'!
* Open. You can then make changes to the template in the Source Editor. G' 1'/
*/ =Dj#gV
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package com.tot.count; xyXa .
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/** 3Jn;}
* ]6j{@z?{
* @author
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*/ #GFr`o0$^
public class CountBean { @2i9n
private String countType; <:CkgR$/{
int countId; ))Za&S*<
/** Creates a new instance of CountData */ r<$y=B
public CountBean() {} M"L=L5OH-
public void setCountType(String countTypes){ }x,S%M-
this.countType=countTypes; /yZcDK4
} 1|:KQl2q
public void setCountId(int countIds){ ;hq\
this.countId=countIds; Q/Rqa5LI:
} h{qgEIk&
public String getCountType(){ 8eRLy/`gd
return countType; #<xm.
} 6aj!Q*(WT
public int getCountId(){ \{NO?%s0p
return countId; VIbq:U
} "<gOzXpa
} N2o7%gJw
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CountCache.java \OoWo
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/* izR"+v
* CountCache.java ~}Pfu
* P$,Ke<
* Created on 2007年1月1日, 下午5:01 $/ ],tSm
* |uJ%5y#
* To change this template, choose Tools | Options and locate the template under Dha1/g1q
* the Source Creation and Management node. Right-click the template and choose ~$J2g
* Open. You can then make changes to the template in the Source Editor. ia?
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*/ [G3E%z
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package com.tot.count; RM/ 0A|
import java.util.*; fN2lLn9/u
/** CvdN"k
* : rVnc =k
* @author cz$2R
*/ T
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public class CountCache { Zwx%7l;C
public static LinkedList list=new LinkedList(); !5N.B|Nt
/** Creates a new instance of CountCache */ St^5Byd<
public CountCache() {} xyxy`qR A
public static void add(CountBean cb){ y
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if(cb!=null){ 7|H$ /]
list.add(cb); }QmqoCAE~m
} _u Il
} xYB{;K
} ;F Eqe49
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CountControl.java 1.>m@Slr>
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/* O".=r}
* CountThread.java QsW/X0YBv
* L RF103nw
* Created on 2007年1月1日, 下午4:57 *NQ/UXE
* V.2_i*
* To change this template, choose Tools | Options and locate the template under e}W)LPR!
* the Source Creation and Management node. Right-click the template and choose phz&zlD
* Open. You can then make changes to the template in the Source Editor. FGkVqZ Y2?
*/ |l!aB(NW
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package com.tot.count; yDh6KUK
import tot.db.DBUtils; D/' dTrR
import java.sql.*; {c0`Um3&>
/** 4Po_-4
* Ea=P2:3*
* @author v-Sd*( 6
*/ 6w7 7YTJ
public class CountControl{ *z2s$EZ
private static long lastExecuteTime=0;//上次更新时间 *lb<$E]="!
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Q59W#e)
/** Creates a new instance of CountThread */ t$ *0{w
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public CountControl() {} @o.I ;}*N
public synchronized void executeUpdate(){ : E?V.
Connection conn=null; `F6C-
PreparedStatement ps=null; p b,. r
try{ :v 4]D4\o
conn = DBUtils.getConnection(); IRbfNq^:
conn.setAutoCommit(false); WF"k[2
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); #LCb
for(int i=0;i<CountCache.list.size();i++){ LgYq.>Nl9
CountBean cb=(CountBean)CountCache.list.getFirst(); [00m/fT6
CountCache.list.removeFirst(); ,+ ~W4<f
ps.setInt(1, cb.getCountId()); !!y a
ps.executeUpdate();⑴ E\$W_Lmr
//ps.addBatch();⑵ Q@H V- (A
} Y\tui+?J
//int [] counts = ps.executeBatch();⑶ !&\INl-Z
conn.commit(); i6N',&jFU
}catch(Exception e){ -$@h1Y
e.printStackTrace(); H)&R=s
} finally{ ItCv.yv35
try{ mA} "a<0
if(ps!=null) { -']56o_sQ/
ps.clearParameters(); ^C%<l(b
ps.close(); \Og+c%
ps=null; "w_aM7x_
} i?;Kq~,
}catch(SQLException e){} 'f|o{
DBUtils.closeConnection(conn); L rPkxmR
} y?!"6t7&
} 4.(4x&
public long getLast(){ *|l/6!WM
return lastExecuteTime; CQ2jP
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} <7$1kGlA
public void run(){ ^}C\zW
long now = System.currentTimeMillis(); jqkqZF
if ((now - lastExecuteTime) > executeSep) { B\n[.(].r
//System.out.print("lastExecuteTime:"+lastExecuteTime); F5#YOck&,
//System.out.print(" now:"+now+"\n"); H:\k}*w
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); "h ^Z
lastExecuteTime=now; aN=B]{!
executeUpdate(); Er[A X.3
} J-4:H
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else{ 'W#D(l9nI
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); !%>7Dw(kt
} bN88ua}k{
} iR0y"Cii
} O1kl70,`R
//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 jRSV
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类写好了,下面是在JSP中如下调用。 cGD(.=
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<% yppo6HGD
CountBean cb=new CountBean(); $7uA%|\
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 5M_H
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CountCache.add(cb); p<;0g9,1
out.print(CountCache.list.size()+"<br>"); ,Lt[\_
CountControl c=new CountControl(); iyog`s c
c.run(); Xry47a
)
out.print(CountCache.list.size()+"<br>"); %07SFu#
%>