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: $kY ]HI
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CountBean.java jR^_1bu
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/* US]I[Y6V
* CountData.java yzyK$WN\[3
* +.66Ky`|[
* Created on 2007年1月1日, 下午4:44 jJe?pT]o
* bfKF6
* To change this template, choose Tools | Options and locate the template under GNoUn7Y
* the Source Creation and Management node. Right-click the template and choose uX+ YH
* Open. You can then make changes to the template in the Source Editor. 8]l(D
*/ 2@|,VN V6~
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package com.tot.count; ?GeMD
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/** F;Bq[V)R
* C]ef
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* @author ??,/85lM
*/ ed$w5dv
public class CountBean { Ev0=m;@_
private String countType; u56WB9Z
int countId; "_n})s
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/** Creates a new instance of CountData */ <!derr-K
public CountBean() {} M[7$F&&n
public void setCountType(String countTypes){ rch Kr w
this.countType=countTypes; __,F_9M
} B;J8^esypD
public void setCountId(int countIds){ b}Xh|0`b+
this.countId=countIds; nc.:Wm6Mj
} Z^#u n
public String getCountType(){ uMK8V_p*?
return countType; *JiI>[
} ,(z"s8N
public int getCountId(){ r)[Xzn
return countId; `"y:/F"{
} @$5=4HA
} 1i;#cIG
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CountCache.java !PJp()
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/* E>bpq^;r
* CountCache.java KDLrt
* 1i@a? 27|
* Created on 2007年1月1日, 下午5:01 #F'8vf'r
* Wn Ng3'6
* To change this template, choose Tools | Options and locate the template under gm7 [m}
* the Source Creation and Management node. Right-click the template and choose %(:{TR
* Open. You can then make changes to the template in the Source Editor. !>)o&sM
*/ E*d UJ.>
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package com.tot.count; _tpOVw4I
import java.util.*; Gk:k
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/** 3|4<SMm
* ?7A>|p?"
* @author 96<0=
*/ Jo:S*D
public class CountCache { 6T%5<I*&3s
public static LinkedList list=new LinkedList(); ,z`* 1b8
/** Creates a new instance of CountCache */ Xx ou1l!
public CountCache() {} \hg%J/
public static void add(CountBean cb){ >YR2h/S
if(cb!=null){ Oe lf^&m
list.add(cb); +nL#c{
} M[ ON2P;
} K7wU
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} h8icF}m
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CountControl.java L$v<t/W
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/* i-R}O6
* CountThread.java L)"CE].
* j8;Uny9
* Created on 2007年1月1日, 下午4:57 X}`39r.
* z[0tM&pv
* To change this template, choose Tools | Options and locate the template under yacN=]SW5
* the Source Creation and Management node. Right-click the template and choose $ J!PSF8PL
* Open. You can then make changes to the template in the Source Editor. X~Hm.qIR
*/ >~ L0M
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package com.tot.count; 3zMaHh)mj
import tot.db.DBUtils; )C0d*T0i
import java.sql.*; J>1%*Tz
/** C@u}tH
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* Op:$7hv
* @author Bv#?.0Ez;
*/ huvn_
public class CountControl{ 5E
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private static long lastExecuteTime=0;//上次更新时间 &.P G2f*
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 HF*j=qt!
/** Creates a new instance of CountThread */ n_kE
public CountControl() {} '1X^@]+6
public synchronized void executeUpdate(){ ]U,m
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Connection conn=null; @ ?bY,
PreparedStatement ps=null; =ba1::18
try{ 5-UrHbpCZ#
conn = DBUtils.getConnection(); &FWz7O>1
conn.setAutoCommit(false); DC0ON`
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ?*'0;K13
for(int i=0;i<CountCache.list.size();i++){ K?>sP%m)
CountBean cb=(CountBean)CountCache.list.getFirst(); 9(lcQuE9
CountCache.list.removeFirst(); RV%)~S@!R
ps.setInt(1, cb.getCountId()); sW76RKX8
ps.executeUpdate();⑴ 4<Kxo\\S
//ps.addBatch();⑵ M9?f`9
} F:8@ ]tA&
//int [] counts = ps.executeBatch();⑶ Q+s2S>U{v
conn.commit(); AOef1^S=
}catch(Exception e){ ~vcua@
e.printStackTrace(); ^0?ww&X
} finally{ <MoyL1=
try{ ijKQ`}JA
if(ps!=null) { (,b\"Q
ps.clearParameters(); (6&"(}Pai
ps.close(); g!^mewtd
ps=null; _}
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} uw(Ml=
}catch(SQLException e){} Gh352
DBUtils.closeConnection(conn); ,s/laZ)V
} FcyFE~>2
} "^wIixOH5
public long getLast(){ ;7*T6~tv
return lastExecuteTime; yw{r:fy
} ~zVe?(W
public void run(){ /#zs
long now = System.currentTimeMillis(); oA3;P]~[
if ((now - lastExecuteTime) > executeSep) { Adgfo)X5
//System.out.print("lastExecuteTime:"+lastExecuteTime); wQa,ol_p
//System.out.print(" now:"+now+"\n"); Y7;=\/SV
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); tl`x/
lastExecuteTime=now; zR)/h
executeUpdate(); O^@F?CG :1
} plpb4>
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else{ )&l5I4CIf
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); (L:Mdo
} uzhTNf
} H-mQ{K^
} ]GD&EQ
//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 ~i!I6d~
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类写好了,下面是在JSP中如下调用。 1fC)&4W
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<% 8Wgzca
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CountBean cb=new CountBean(); /T+%q#4
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); bt Bu[;
CountCache.add(cb); t%Bh'HkG
out.print(CountCache.list.size()+"<br>"); $-]I?cWlQ
CountControl c=new CountControl(); E&f/*V^
c.run(); PcI~,e%
out.print(CountCache.list.size()+"<br>");
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%>