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: @QX4 \
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CountBean.java ZgK@Fl*k
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/* m9k2h1
* CountData.java s1v{~xP
* fW[_+r]
* Created on 2007年1月1日, 下午4:44 8m \;P
* zM)M_L
* To change this template, choose Tools | Options and locate the template under #W.bZ]&WA
* the Source Creation and Management node. Right-click the template and choose %K`4k.gN
* Open. You can then make changes to the template in the Source Editor.
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*/ `}ZL'\G
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package com.tot.count; oX2r?.j#M
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/** &4[<F"W>47
* <)"iL4 kDI
* @author Scf.4~H 0
*/ 2Sv>C `FMU
public class CountBean { YqkA&qL]#;
private String countType; 9B&
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int countId; t<8z08
/** Creates a new instance of CountData */ 5NFq7&rJ6
public CountBean() {} A<]&JbIt
public void setCountType(String countTypes){ \gjl^#;
this.countType=countTypes; EwC5[bRjUp
} |:{g?4Mi
public void setCountId(int countIds){ "hJ7 Vv_
this.countId=countIds; e3G7K8
} 6_x}.bkIx=
public String getCountType(){ elNB7%Y/
return countType; <d3PDO@w/
} wbn^R'
public int getCountId(){ OA\vT${5
return countId; N;e}dwh&
} &9S8al
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} )j$b9ZBk
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CountCache.java tvGg@Xs\
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/* IY-(-
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* CountCache.java vQ?MM&6
* ^U R-#WaQ
* Created on 2007年1月1日, 下午5:01 &Xj {:s#
* U]+b`m
* To change this template, choose Tools | Options and locate the template under oFX"F0rx
* the Source Creation and Management node. Right-click the template and choose JS }_q1H
* Open. You can then make changes to the template in the Source Editor. OaX HJ^k
*/ WK/b=p|#o
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package com.tot.count; ^Tb}]aHg
import java.util.*; z_5rAlnwT.
/** 1jR=h7^=
* GLbc/qs
* @author PmuEL@'^ U
*/ oAIY=z
public class CountCache { b|\{ !N]
public static LinkedList list=new LinkedList(); 9Ba%=
/** Creates a new instance of CountCache */ R !:eYoQ
public CountCache() {} KqT#zj
public static void add(CountBean cb){ v9X7-GJ~
if(cb!=null){ [a#?}((
list.add(cb); jV(xYA3
} # CP9^R S
} 0R2S@4%Y
} Y^*Lh/:h
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CountControl.java :pL1F)-*
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/* f}evw K[S
* CountThread.java
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* >x|A7iWn{,
* Created on 2007年1月1日, 下午4:57 '7RR2f>V
* Zpn*XG
* To change this template, choose Tools | Options and locate the template under op.PS{_t
* the Source Creation and Management node. Right-click the template and choose Q{ |+3!!'
* Open. You can then make changes to the template in the Source Editor. }QApeZd+q
*/ W[jW;uk
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package com.tot.count; 1A)wbH)
import tot.db.DBUtils; k`iq<b
import java.sql.*; Q9 x` Uy
/** fed[^wW
* $Nt]${0
* @author mTb2d?NS
*/ 7Dx .;
public class CountControl{ Bcd0
private static long lastExecuteTime=0;//上次更新时间 |aOnV,}
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 e5"-4udCn
/** Creates a new instance of CountThread */ 4/mj"PBKL
public CountControl() {} 2\iD;Z#gM
public synchronized void executeUpdate(){ JUaKj@a|
Connection conn=null; (`uC"M Lk
PreparedStatement ps=null; +gD)Yd
try{ s6eq?1l3
conn = DBUtils.getConnection(); u[6`Jr~
conn.setAutoCommit(false); ?SsRN jeL
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); DY+8m8!4H
for(int i=0;i<CountCache.list.size();i++){ @]VvqCk
CountBean cb=(CountBean)CountCache.list.getFirst(); +2k|g2
CountCache.list.removeFirst(); Tr}$Pb1
ps.setInt(1, cb.getCountId()); 7Hr4yh[j&
ps.executeUpdate();⑴ ke;*uS
//ps.addBatch();⑵ [y&h_w.
} 4{;8 ]/.a
//int [] counts = ps.executeBatch();⑶ Ph7(JV{
conn.commit(); ?`[ uh%
}catch(Exception e){ qzU2H
e.printStackTrace(); xzGsfd
} finally{ WHD/s
try{ ?` ZGM
if(ps!=null) { ` $x#_-Hn
ps.clearParameters(); c_8 mQ
ps.close(); 1o"oa<*_
ps=null; <K.C?M(9
} 'm p{O
}catch(SQLException e){} LXLIos55S
DBUtils.closeConnection(conn); %>z8:oJ
} (Ss77~W7
} gJ[q
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public long getLast(){ >J75T1PH=
return lastExecuteTime; '>WuukC
} E,yzy[gl
public void run(){ R7;rBEt8
long now = System.currentTimeMillis(); LXEu^F~{u#
if ((now - lastExecuteTime) > executeSep) { $^+KR]\q
//System.out.print("lastExecuteTime:"+lastExecuteTime); ^[?+=1
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//System.out.print(" now:"+now+"\n"); )eGu4iEPM
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); #?|1~HC
lastExecuteTime=now; h'q0eqYeu)
executeUpdate(); )1yUV*6
} ][K8\
else{ IOES3
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); tS/APSY
} _(s|Q
} AiHDoV+-
} k-PRV8WO
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 U!UX"r
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类写好了,下面是在JSP中如下调用。 Pv$"DEXA2
% |Gzht\
<% ^A$XXH'
CountBean cb=new CountBean(); 1B]wSvP@
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); yD
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CountCache.add(cb); ~Wd8>a{w
out.print(CountCache.list.size()+"<br>"); `[u>NEb
CountControl c=new CountControl(); i@?<]n
c.run(); XK9*,WA9r
out.print(CountCache.list.size()+"<br>"); ia.B@u1/
%>