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: blN1Q%m6
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CountBean.java %@&)t?/=
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/* ]czy8n$+
* CountData.java )[K3p{4
* ibuI/VDF
* Created on 2007年1月1日, 下午4:44 #]
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* U KJY.W!w4
* To change this template, choose Tools | Options and locate the template under Q]7Q
* the Source Creation and Management node. Right-click the template and choose \fKE~61
* Open. You can then make changes to the template in the Source Editor. `P5"5N\h
*/ .~U9*5d
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package com.tot.count; IB6]Wj
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/** sR9F:
* i@J,u
* @author \O:xw-eG
*/ \S<5b&G
public class CountBean { Ax^'unfQ:
private String countType; h[8y$.YsC
int countId; #CS>A#Lk
/** Creates a new instance of CountData */ lX4p'R-h
public CountBean() {} 2bJFlxEU
public void setCountType(String countTypes){ c'B"Onu@m*
this.countType=countTypes; "n6Y^
} l =yHx\
public void setCountId(int countIds){ 9A_7:V]_
this.countId=countIds; /)I9+s#q9o
} vvM)Rb,
public String getCountType(){ hjG1fgEj
return countType; }gW}Vr <
} mCGcM^21-x
public int getCountId(){ uf^:3{1
return countId; ".)_kt[
} O$H150,Q
} H+;wnI>@
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CountCache.java ^8m+*t
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/* Vd0GTpB?1
* CountCache.java qj6`nbZ{va
* t4IJ%#22
* Created on 2007年1月1日, 下午5:01 =vc5,
* Rpk`fxAO
* To change this template, choose Tools | Options and locate the template under `"H?nf0
* the Source Creation and Management node. Right-click the template and choose Ds87#/Yfv
* Open. You can then make changes to the template in the Source Editor. rxK0<pWJhx
*/ K|G$s
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package com.tot.count; -"e}YN/
import java.util.*; &XsLp&Do2
/** lz (,;I'x
* %)9]dOdOk
* @author T,uIA]
*/ gxOmbQt@;
public class CountCache { V</T$V$
public static LinkedList list=new LinkedList(); z\tJ~
/** Creates a new instance of CountCache */ B0i}Y-Z
public CountCache() {} T]|O/
public static void add(CountBean cb){ gn"&/M9E
if(cb!=null){ OQ7c|O
list.add(cb); AuTplO0_rE
} <dL04F
} h,>L(=c$O
} >p*HXr|o$
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CountControl.java N
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/* 9@Sb! 9h
* CountThread.java %20-^&zZ
* n6G&^Oj
* Created on 2007年1月1日, 下午4:57 =BS'oBn^6
* XQOprIJ
U
* To change this template, choose Tools | Options and locate the template under SSLshY~d
* the Source Creation and Management node. Right-click the template and choose ^qx\ e$R
* Open. You can then make changes to the template in the Source Editor. a{*'pY(R0$
*/ Z5Ihc%J^
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package com.tot.count; qm=F6*@}
import tot.db.DBUtils; ! |h2&tH
import java.sql.*; {,FeNf46
/** " B{0-H+
* 4p8jV*:@{
* @author f*vk1dS:*3
*/ mzB#O;3=
public class CountControl{ pqN[G=0
private static long lastExecuteTime=0;//上次更新时间 k6L373e#Q
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 )[sO5X7'^
/** Creates a new instance of CountThread */ {H;|G0tR
public CountControl() {} t!SQLgA
public synchronized void executeUpdate(){ E$tk1SVo
Connection conn=null; +~Lzsh"
PreparedStatement ps=null; htYrv5q=M
try{ -Y=c g;
conn = DBUtils.getConnection(); d:pm|C|F
conn.setAutoCommit(false); %`T5a<
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); M3@fc,Ch
for(int i=0;i<CountCache.list.size();i++){ 6Y)^)dOi
CountBean cb=(CountBean)CountCache.list.getFirst(); !*Z)[[
CountCache.list.removeFirst(); m=\eL~h
ps.setInt(1, cb.getCountId()); ev%t5NZ
ps.executeUpdate();⑴ MD4 j~q\g
//ps.addBatch();⑵ 1IQOl
} +Z&&H'xD
//int [] counts = ps.executeBatch();⑶ z%3"d0
conn.commit(); = )l: ^+q
}catch(Exception e){ "!Oh#Vf
e.printStackTrace(); DUKmwKM"k
} finally{ yr9A0F0
try{ aE+$&_>ef
if(ps!=null) { .cS,T<$
ps.clearParameters(); 0aTbzOn&
ps.close(); G\N"rG =
ps=null; SE9u2Jk
} qm8n7Z/
}catch(SQLException e){} C.)&FW2F_
DBUtils.closeConnection(conn); Bb[e[,ah
} gDNTIOV
} y2"S\%7$h
public long getLast(){ z!C4>,
return lastExecuteTime; G\>\VA
} +.#S[G
public void run(){ `J#xyDL6?
long now = System.currentTimeMillis(); l[ ": tG
if ((now - lastExecuteTime) > executeSep) { a]Da`$T
//System.out.print("lastExecuteTime:"+lastExecuteTime); uM)9b*Vbo
//System.out.print(" now:"+now+"\n"); n+\Cw`'<H
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 1X"H6j[w
lastExecuteTime=now; ICCCCG*[
executeUpdate(); QGv:h[b_
} ~q?"w:@;x
else{ G'?f!fz;
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 7cmr
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} ]7S7CVDk4
} , HI%Xn
} ym*#ZE`B!
//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 Y0X94k.u
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类写好了,下面是在JSP中如下调用。 5?{ >9j5
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<% *o e0=
CountBean cb=new CountBean(); w4fJ`,
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); &PBWJ?@O)r
CountCache.add(cb); a.}:d30
out.print(CountCache.list.size()+"<br>"); 4R*<WdT(
CountControl c=new CountControl(); m wEVEx24
c.run(); BRU9LS
out.print(CountCache.list.size()+"<br>"); .`Old{<
%>