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: *G$tfb(
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CountBean.java Os9xZ
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/* TPp%II'*
* CountData.java InMeD[*^
* DqrS5!C
* Created on 2007年1月1日, 下午4:44 NFPW#-TF
* L~Epd.,Dt
* To change this template, choose Tools | Options and locate the template under qHg\n)R"x!
* the Source Creation and Management node. Right-click the template and choose eh nN
* Open. You can then make changes to the template in the Source Editor. /<s'@!W
*/ (L8H.|.
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package com.tot.count; Bm"jf]
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/** Skl1%`
* e-H:;m5R
* @author d~uK/R-KD
*/ ^10*s,(uS?
public class CountBean { 4VSIE"8e
private String countType; cysYjuI i
int countId; WZdA<<,:o
/** Creates a new instance of CountData */ V:)k@W?P
public CountBean() {} eI; %/6#
public void setCountType(String countTypes){ 4vPQuk!
this.countType=countTypes; Fe%Q8RIh_
} ;o_4)+}
public void setCountId(int countIds){ ~UB@IV6O
this.countId=countIds; soA>&b!?
} FVT_%"%C9
public String getCountType(){ .VuZ=
return countType; 7EOn4I2@[
} #* j
public int getCountId(){ !0`44Gbq
return countId; V/$qD
} Duj9PV`2
} ik_Ll|
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CountCache.java FgrOZI;_
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/* KR%p*Nh+C
* CountCache.java ]zmY]5
* BM&95p
* Created on 2007年1月1日, 下午5:01 U:~O^
*
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* To change this template, choose Tools | Options and locate the template under Ex^7`-2,B
* the Source Creation and Management node. Right-click the template and choose ?%i|].<-'
* Open. You can then make changes to the template in the Source Editor. ^;$a_eR
*/ [ahD%UxO5
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package com.tot.count; IX']s;b
import java.util.*; f}Eoc>n
/** D@!`b6
* WM*[+8h
* @author `]_#_
*/ 0qnToV;
public class CountCache { Z9cch-u~
public static LinkedList list=new LinkedList(); ~ULuX"n
/** Creates a new instance of CountCache */ fBR,Oneo
public CountCache() {} (\e,,C%;
public static void add(CountBean cb){ VzA~w`$d
if(cb!=null){ *^ \xH ,.
list.add(cb); `8\_ ]w0
} 0yfmQ=,X
} H\W60|z9
} u^s{r`/
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CountControl.java <oS2a/Nd
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/*
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* CountThread.java O`g44LW2n
* *JZU
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* Created on 2007年1月1日, 下午4:57 ,oT?-PC$z
* 2shr&Mfp[
* To change this template, choose Tools | Options and locate the template under BLgmFE2
* the Source Creation and Management node. Right-click the template and choose 1RY}mq
* Open. You can then make changes to the template in the Source Editor. "S(m1L?
*/ <,(6*b
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package com.tot.count; &dp(CH<De
import tot.db.DBUtils; w1KLQd:yq
import java.sql.*; Se9I1~mX
/** *^bqpW2$q
* +M$2:[xRT
* @author )a.w4dH
*/ j/TsHJ=
public class CountControl{ .M!6${N);
private static long lastExecuteTime=0;//上次更新时间 =O?<WJoK
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 2P`hdg
/** Creates a new instance of CountThread */ 1y$Bz?4
public CountControl() {} 5u'"m<4
public synchronized void executeUpdate(){ ~e@QJ=r
Connection conn=null; B'"C?d<7
PreparedStatement ps=null; A-aukJg9
try{ G#ZU^%$M,
conn = DBUtils.getConnection(); ^*#5iT8/
conn.setAutoCommit(false); J
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); TFb9gOTJ
for(int i=0;i<CountCache.list.size();i++){ Ytm t+9
CountBean cb=(CountBean)CountCache.list.getFirst(); 9n]zh-
CountCache.list.removeFirst();
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ps.setInt(1, cb.getCountId()); %k_R;/fjW
ps.executeUpdate();⑴ s+YQ
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//ps.addBatch();⑵ 5&D)W>{d
} rY4{,4V
//int [] counts = ps.executeBatch();⑶ wo5"f}vd#
conn.commit(); x[U/
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}catch(Exception e){ Z)<ljW
e.printStackTrace(); T~J6(,"
} finally{
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try{ m{9m.~d
if(ps!=null) { !FX0Nx=oi
ps.clearParameters(); }` E5I&r4
ps.close(); <f%JZ4p*
ps=null; P95U{
} w{f!t8C*s
}catch(SQLException e){} /5 B{szf
DBUtils.closeConnection(conn); |&eZ[Sy(=l
} xQ\/6|
} TCYjj:/
public long getLast(){ S9S8T+
return lastExecuteTime; ~UA-GWb
} f=]+\0MQ
public void run(){ 5+\[x`
long now = System.currentTimeMillis(); e`
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if ((now - lastExecuteTime) > executeSep) { x9k(mn%,
//System.out.print("lastExecuteTime:"+lastExecuteTime); \W=~@k
//System.out.print(" now:"+now+"\n"); 28[hp[<
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); secD
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lastExecuteTime=now; 9\ZlRYnc=
executeUpdate(); 43-mv1>.
} {G&*\5W
else{ f4YcZyBGv
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); n[8ju,=
} XdE#l/#
} S
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} ^
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//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 \ofWD{*j
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类写好了,下面是在JSP中如下调用。 QxZYy}2
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<% <wWZ]P2]
CountBean cb=new CountBean(); gw' uY$
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); d/5i4g[q
CountCache.add(cb); AdB B#zd
out.print(CountCache.list.size()+"<br>"); |YCGWJaci
CountControl c=new CountControl(); _^K)>
c.run(); uJ<nW%}
out.print(CountCache.list.size()+"<br>"); Z BjyQ4h
%>