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: eBw6k09C+
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CountBean.java @m*^v\q<u
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/* }=)
* CountData.java <B,z)c
* p[kEFE,%
* Created on 2007年1月1日, 下午4:44 nP9zTa
* ko-:)z
* To change this template, choose Tools | Options and locate the template under NWK+.{s>m
* the Source Creation and Management node. Right-click the template and choose 85$W\d
* Open. You can then make changes to the template in the Source Editor. ``l7|b jJ
*/ |7
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package com.tot.count; H}TzNs
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/** 0FL PZaRP
* zq(R !a6
* @author Q&p'\6~
*/ 9NX/OctFa'
public class CountBean { Dwvd
private String countType; nYfZ[Q>v
int countId; LP_w6fjT
/** Creates a new instance of CountData */ Knd2s~S
public CountBean() {} G5JZpB#o
public void setCountType(String countTypes){ :C%cnU;N
this.countType=countTypes; 8KQD
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} $@H]0<3,
public void setCountId(int countIds){ Qw&It
this.countId=countIds; ?Q`u\G3.m
} u$A*Vsmr
public String getCountType(){ |&O7F;/_
return countType; =&kd|o/i
} *|Cmm>z"7
public int getCountId(){ x RV@_
return countId; }Xn5M&>?
} Yv}V =O%
} pf_(?\oz>
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CountCache.java :BIgrz"Jz
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/* \YV`M3O
* CountCache.java W<W5ih,#
* #x)lN
* Created on 2007年1月1日, 下午5:01 =#tQhg,_
* @"B"*z-d
* To change this template, choose Tools | Options and locate the template under Re`'dde=
* the Source Creation and Management node. Right-click the template and choose HY
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* Open. You can then make changes to the template in the Source Editor. D_n(T')
*/ )0RznFJ+X
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package com.tot.count; JYE[
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import java.util.*; AD_aI
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/** !KYX\HRW
* q6xm#Fd'.
* @author 3_AVJv
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*/ 4tv}5llSG
public class CountCache { DOk(5gR
public static LinkedList list=new LinkedList(); 7hg)R
@OC
/** Creates a new instance of CountCache */ ;@I4[4ph}
public CountCache() {} :$=r^LSH
public static void add(CountBean cb){ 4[\[Ho
if(cb!=null){ 6k|^Cs6~z
list.add(cb); +\@)
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} {w,g~ew
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} D7|=ev
} @qszwQav$
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CountControl.java Sqt'}
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/* y":Y$v,P
* CountThread.java 3,x|w
* n"p|tEK
* Created on 2007年1月1日, 下午4:57 Stw%OP@?
* a{oG[e
* To change this template, choose Tools | Options and locate the template under 38I .1p9
* the Source Creation and Management node. Right-click the template and choose ,};UD
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* Open. You can then make changes to the template in the Source Editor. h3}gg@Fm
*/ sBsf{%I[{
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package com.tot.count; 9GH11B_A
import tot.db.DBUtils; G-54D_ 4
import java.sql.*; f{m,?[1C,
/** x/Nh9hh"
* ]HpKDb0+
* @author O.ce"5Y^
*/ C`p)S`d
public class CountControl{ 5x([fG
private static long lastExecuteTime=0;//上次更新时间 F4Jc7k2
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 x4r=ENO)q
/** Creates a new instance of CountThread */ L<GF1I)
public CountControl() {} ~E]ct F
public synchronized void executeUpdate(){ N+l 0XjZD9
Connection conn=null; _8-iO.T+2
PreparedStatement ps=null; (W=J3?hn
try{ ;w\7p a
conn = DBUtils.getConnection(); 2}NWFM3C
conn.setAutoCommit(false); 2HxT+|~d6
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 88K=jo))b
for(int i=0;i<CountCache.list.size();i++){ ?1DA
CountBean cb=(CountBean)CountCache.list.getFirst(); Y,?!"
CountCache.list.removeFirst(); CG`s@5y>5
ps.setInt(1, cb.getCountId()); __F?iRrCM
ps.executeUpdate();⑴ `cz%(Ry,
//ps.addBatch();⑵ e 58
} uQ} 0hs
//int [] counts = ps.executeBatch();⑶ R a> k#pQ
conn.commit(); /b$0).fj@,
}catch(Exception e){ fmDn1N-bG
e.printStackTrace(); 2l7Sbs7
} finally{ m'L7K K-Y)
try{ 'aq9]D_k
if(ps!=null) { $r>\y (W
ps.clearParameters(); lphELPh
ps.close(); \0{g~cU4
ps=null; 6m=FWw3y
} 6:(R/9!P
}catch(SQLException e){} \[nvdvJv
DBUtils.closeConnection(conn); NXJyRAJ*%
} d]kP@flOV
} -G!W6$Y
public long getLast(){ c
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return lastExecuteTime; li U=&wM>
} 5|4=uoA<
public void run(){ cz2guUu
long now = System.currentTimeMillis(); ,b&-o?.{
if ((now - lastExecuteTime) > executeSep) {
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//System.out.print("lastExecuteTime:"+lastExecuteTime); 1l8kuwH
//System.out.print(" now:"+now+"\n"); dG}.T_l
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); e:h(,
lastExecuteTime=now; POnI&y]
executeUpdate(); jJX-S
} M-K.[}}-d
else{ h1y6`m9
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); L\:f#b~W
} SGZ]_
} H1FD|Q3
} r35'U#VMk?
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 4 yk!T
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类写好了,下面是在JSP中如下调用。 P ~pC /z
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<% 7]i=eD8
CountBean cb=new CountBean(); dzK]F/L]
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); j:JM v
CountCache.add(cb); vlHE\%{
out.print(CountCache.list.size()+"<br>"); s+=JT+g
CountControl c=new CountControl(); P,(Tu.EPk
c.run(); l$i^e|*
out.print(CountCache.list.size()+"<br>"); Ab"mX0n
%>