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: SZvsJ)
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CountBean.java KK</5Aw9p
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/* )3sb2
#
* CountData.java mN02T@R-
* za7wNe(s
* Created on 2007年1月1日, 下午4:44 _wCSL.
* e$=|-Jz
* To change this template, choose Tools | Options and locate the template under J?'!8,RX
* the Source Creation and Management node. Right-click the template and choose X)m2{@v D
* Open. You can then make changes to the template in the Source Editor. {'!~j!1'j
*/ h#
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package com.tot.count; YPl{5=
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/** c&&UT-Z
* #Gx@\BE{
* @author X;h~s:LM
*/
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public class CountBean { ~_%[j8o&l
private String countType; pG&.Ye]j
int countId; M .,|cx
/** Creates a new instance of CountData */ 2uIAnbW]M
public CountBean() {} FhGbQJ?[3
public void setCountType(String countTypes){ z@~rm9d
this.countType=countTypes; 14RL++
} pjFgIG2=9
public void setCountId(int countIds){ B|v
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this.countId=countIds; n:P}K?lg
} ?3#X5WT
public String getCountType(){ srL,9)OC
return countType; xh0!H|
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} uypD`%pC
public int getCountId(){ LKa_ofY
return countId; P6Ei!t,>
} x%1Rp[
} M3%<kk-_
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CountCache.java ;G$FLL1
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/* #'qW?8d}
* CountCache.java 1a<~Rmcil
* 2 O%UT?R
* Created on 2007年1月1日, 下午5:01 6k2~j j1d
* Y2Bu,/9^
* To change this template, choose Tools | Options and locate the template under A@UnrbX:
* the Source Creation and Management node. Right-click the template and choose bPNsy@"6
* Open. You can then make changes to the template in the Source Editor. a'BBp6
*/ 1Q<a+
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package com.tot.count; \T0`GpE
import java.util.*; X`&E,;bIb
/** D$\ EZ
* $3>|RlxYA
* @author \;}dSSB1
*/ "T PMSx&Ei
public class CountCache { o%:eYl
public static LinkedList list=new LinkedList(); g:HIiGN0Ic
/** Creates a new instance of CountCache */ 2sngi@\
public CountCache() {} P+[R 0QS
public static void add(CountBean cb){ 8MIHp[vm%
if(cb!=null){ Ne%X:h
list.add(cb); WVZ\4y
} c}A^0,"z>
} AOpfByw
} fOfp.`n
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CountControl.java ]l`DR4
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/* VrpYBU
* CountThread.java BtspnVBez
* q6q=,<T%S
* Created on 2007年1月1日, 下午4:57 7 UR)4dYA
* &A~ 1Q#4
* To change this template, choose Tools | Options and locate the template under a`}-^;}SW
* the Source Creation and Management node. Right-click the template and choose !T}`h'
* Open. You can then make changes to the template in the Source Editor. 7r>^_ aW
*/ Ex<loVIrP$
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package com.tot.count; /Mv'fich(
import tot.db.DBUtils; D3eK!'qS
import java.sql.*; Js'|N%pi
/** >QYxX<W
* @I%m}>4Jm
* @author b+kb7
*/ X:YxsZQ5Y
public class CountControl{ Z=#!FZ{
private static long lastExecuteTime=0;//上次更新时间 q;rU}hAzG0
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ^VA)vLj@
/** Creates a new instance of CountThread */ _Q QO&0Z
public CountControl() {} =&vV$UtV
public synchronized void executeUpdate(){ YPN|qn(
Connection conn=null; 4WLB,<b}
PreparedStatement ps=null; /SyiJCx0
try{ s;bqUY?LD
conn = DBUtils.getConnection(); BzDS
conn.setAutoCommit(false); T6tJwSS4:
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); bcQ$S;U)
for(int i=0;i<CountCache.list.size();i++){ U9Sp$$L
CountBean cb=(CountBean)CountCache.list.getFirst(); *Nv<,Br,F
CountCache.list.removeFirst(); Xh?{%?2
ps.setInt(1, cb.getCountId()); T+I|2HYqOj
ps.executeUpdate();⑴ N7|ctO
//ps.addBatch();⑵ 6uD Nqq
} s;>jy/o0 s
//int [] counts = ps.executeBatch();⑶ , =#'?>Kq
conn.commit(); Ox58L>:0m
}catch(Exception e){ EM"YjC)F
e.printStackTrace(); #6JG#!W
} finally{ /gxwp:&lY
try{ [K^RC;}nV^
if(ps!=null) { 'INdZ8j_
ps.clearParameters(); cEe>Lyt
ps.close(); !aLL|}S
ps=null; T7[ItLZ
} zzM 'uo
}catch(SQLException e){} /MA4Er r
DBUtils.closeConnection(conn); .2`S07Z
} s+aeP
} `Do-!G+W
public long getLast(){ <MoWS9s!yb
return lastExecuteTime; |',Gy\Sj
} B7cXbUAQs
public void run(){ By"
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long now = System.currentTimeMillis(); }_K7}] 1
if ((now - lastExecuteTime) > executeSep) { JD.WH|sZ5
//System.out.print("lastExecuteTime:"+lastExecuteTime); ?>2k>~xlQ
//System.out.print(" now:"+now+"\n"); hW(Mf
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); m!g
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lastExecuteTime=now; lOql(ZH`w
executeUpdate(); Y6+nfh_
} hS<+=3
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else{ 8xLvpgcZ
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); leiP/D6s
} <}G7#xg
} `w2hJP
} 90;[5c
//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 }.x?$C+\"
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类写好了,下面是在JSP中如下调用。 A%pcPzG;
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<% K"eW.$
CountBean cb=new CountBean(); QD<f)JZK
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); :hZYh.y\l
CountCache.add(cb); op;OPf,
out.print(CountCache.list.size()+"<br>"); >-f`mT
CountControl c=new CountControl(); k\A8Z[
c.run(); ]"^U
out.print(CountCache.list.size()+"<br>"); -Zkl\A$>
%>