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: $o^}<)DW
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CountBean.java 3N\X{za
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/* rbWFq|(_
* CountData.java !qq@F%tv
* H[oi? {L
* Created on 2007年1月1日, 下午4:44 ?RyvM_(N6
* yV`vu/3K
* To change this template, choose Tools | Options and locate the template under /iy/2x28>
* the Source Creation and Management node. Right-click the template and choose @UBp;pb}=h
* Open. You can then make changes to the template in the Source Editor. ]sE^=;Pv?
*/ b`=rd 4cpU
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package com.tot.count; N/p_6GYMa
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/** AO]e^Q
* BJTljg({o
* @author N9Vcp~;
*/ ABf#!G
public class CountBean { b*7i&q'H
private String countType; z""(M4
int countId; uEY5&wX`
/** Creates a new instance of CountData */ )nV x 2m4
public CountBean() {} (~4AG \
public void setCountType(String countTypes){ ]5CFL$_Q{
this.countType=countTypes; ~*WbMA
} MDt4KD+bZ
public void setCountId(int countIds){ Yzz8:n
this.countId=countIds; To95WG7G
} VI{1SIhfa
public String getCountType(){ R/7l2 *
return countType; M,P_xkLp
} !Ai;S
public int getCountId(){ 7Q&P4{hi0
return countId; #/6X44
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} <Do89
} %-.GyG$i
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CountCache.java )c_ll;%
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/* J KGZ0yn
* CountCache.java MvA_tRO
* ~Fh(4'
* Created on 2007年1月1日, 下午5:01 vJ s/ett
* JJr<cZ4]
* To change this template, choose Tools | Options and locate the template under O5w\oDhMb
* the Source Creation and Management node. Right-click the template and choose Ig2VJ s;
* Open. You can then make changes to the template in the Source Editor. [; bLlS,
*/ |ipppE=
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package com.tot.count; J/ ~]A1fP6
import java.util.*; }I0^nv1
/** > im4'-
* *BV .zbGm
* @author #;)7~69
*/ O)?0G$0
public class CountCache { >'eqOZM
public static LinkedList list=new LinkedList(); V^D#i(5
/** Creates a new instance of CountCache */ g}7B0 yo
public CountCache() {} 0%GWc}o
public static void add(CountBean cb){ s&l[GKR
if(cb!=null){ +J}M$eQ
list.add(cb); 8,Z0J
} ' =kX
} lPQH_+)Z"
} X,b}d#\
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CountControl.java [S%
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/* n >^?BU
* CountThread.java 9cQSS'`F
* WF]:?WE%
* Created on 2007年1月1日, 下午4:57 \`^jl
* g|oPRC$I'
* To change this template, choose Tools | Options and locate the template under VI4d/2e
* the Source Creation and Management node. Right-click the template and choose R.7"ZG
* Open. You can then make changes to the template in the Source Editor. <5
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*/ {>qCZ#E5WO
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package com.tot.count; gDrqs>8
import tot.db.DBUtils; \]D;HR`vo
import java.sql.*; e-WaK0Ep
/** !}%giF$-
* [
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* @author {+ m)*3~w
*/ w;:,W@K
public class CountControl{ *w;f\zW
private static long lastExecuteTime=0;//上次更新时间 j8b:+io
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 7hc(]8eP
/** Creates a new instance of CountThread */ BBDOjhik
public CountControl() {} hf'3yEm
public synchronized void executeUpdate(){ 2+'&||h
Connection conn=null; 5"sF#Y&
PreparedStatement ps=null; ifkA3]
try{ j(SQNSFD
conn = DBUtils.getConnection(); _i&\G}mrC
conn.setAutoCommit(false); mnePm{
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); $T6<9cB@
for(int i=0;i<CountCache.list.size();i++){ >&TktQO_T
CountBean cb=(CountBean)CountCache.list.getFirst(); T'X Rl@
CountCache.list.removeFirst(); >wn&+%i&
ps.setInt(1, cb.getCountId()); W^x[maz
ps.executeUpdate();⑴ @1pdyKK
//ps.addBatch();⑵ =F`h2 A;a
} gm8H)y,
//int [] counts = ps.executeBatch();⑶ ^a]:GPc
conn.commit(); nL$tXm-x
}catch(Exception e){ REw3>/=
e.printStackTrace(); >TE&myZ?*
} finally{ [x&&N*>N
try{ 1Dbe0u
if(ps!=null) { t :_7O7
ps.clearParameters(); `yhL11]~
ps.close(); .C1^QY-wL
ps=null; F'K{=
} *6h.#$\
}catch(SQLException e){} </fnbyGR
DBUtils.closeConnection(conn); w-KtxG(
} Lh+^GQ
} BdceINI
public long getLast(){ $6_J`7
return lastExecuteTime; pD]Ry"
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} ?TXFOr]g]2
public void run(){ bx@CzXre;
long now = System.currentTimeMillis(); -{O2Nv- ]]
if ((now - lastExecuteTime) > executeSep) { 6Hz=VhQrN
//System.out.print("lastExecuteTime:"+lastExecuteTime); -*WD.|k
//System.out.print(" now:"+now+"\n"); &,\S<B2.
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); \nLO.,
lastExecuteTime=now; \3KCZ
executeUpdate(); `@ObM[0p(
} {>i'Pb0mG|
else{ l6O2B/2j
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 71~V*
} wxoBq{r;
} L3/ua
} U{ Y)\hR-
//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 A_2ppEG
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类写好了,下面是在JSP中如下调用。 8z+ CYeV
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<% F2u{Wzr_@
CountBean cb=new CountBean(); bZ389dSn
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); kqyY:J
CountCache.add(cb); H1X6f7`
out.print(CountCache.list.size()+"<br>"); Y-Z.AA,
CountControl c=new CountControl(); V'9 k;SF
c.run(); 6PTD%Rf\
out.print(CountCache.list.size()+"<br>"); ,0~'#x>
%>