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: u!O)\m-
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CountBean.java },l3N K
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/* MD +Q_
* CountData.java +7=3[K
* B9]KC i
* Created on 2007年1月1日, 下午4:44 (uSfr]89'
* S;Vj5
* To change this template, choose Tools | Options and locate the template under [ACa<U/
* the Source Creation and Management node. Right-click the template and choose um/iK}O
* Open. You can then make changes to the template in the Source Editor. 8"+Kz
*/ r'&VH]m
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package com.tot.count; 4XRVluD%W.
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/** p &A3l
* [L:,A{rve
* @author 0ZO!_3m$r
*/ /0A}N$?>:
public class CountBean { V[#jrwhA
private String countType; :p89J\
int countId; _f/6bpv
/** Creates a new instance of CountData */ >y5~:L
public CountBean() {} ct`89~"
public void setCountType(String countTypes){ Hd
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this.countType=countTypes; \]zHM.E1
} gF&1e5`i
public void setCountId(int countIds){ Zf ;U=]R
this.countId=countIds; GujmBb
} 'Je;3"@
public String getCountType(){ BPW2WSm@<
return countType; HN\9d
} 0y*8;7-|r)
public int getCountId(){ {$Qw]?Yv
return countId; @,$>H7o
} EsdA%`
} d4~!d>{n|c
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CountCache.java />H9T[3=
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/* }5`Kn}rY
* CountCache.java s~3"*,3@
* {>9vm!<[*\
* Created on 2007年1月1日, 下午5:01 `2G 0B@
* ^)TZHc2a[
* To change this template, choose Tools | Options and locate the template under qeypa!
* the Source Creation and Management node. Right-click the template and choose +Y-Gp4"
* Open. You can then make changes to the template in the Source Editor. r3'0{Nn+
*/ 8K'3iw>z
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package com.tot.count; XsEDI?p2
import java.util.*; 09/Mg
/** ,VI2dNst\
* 6YNd;,it>p
* @author U&GSMjqg
*/ voiWf?X
public class CountCache { )m|)cLT&
public static LinkedList list=new LinkedList(); f]Xh7m(Gh
/** Creates a new instance of CountCache */ H>X:#xOA_
public CountCache() {} 1
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public static void add(CountBean cb){ y2cYRHN[X}
if(cb!=null){ !#3v<_]#d
list.add(cb); *jM]:GpyoU
} G8}k9?26(
} XkDIP4v%
} I|(r1.[K
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CountControl.java pC^d-Ii
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/* K|]/BjB/
* CountThread.java s+DOr$\
* n&1q*
* Created on 2007年1月1日, 下午4:57 NYw>Z>TD8c
* :<hM@>eFn
* To change this template, choose Tools | Options and locate the template under #A\@)wJ
* the Source Creation and Management node. Right-click the template and choose k..AP<hH
* Open. You can then make changes to the template in the Source Editor. }20~5!
*/ uVN2}3!)Y
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package com.tot.count; W[/Txc0$
import tot.db.DBUtils; WUrE1%u
import java.sql.*; 0~4Ww=#
/** E6XDn`:
* k'QI`@l&l
* @author IK1'" S|
*/ nvbzC tC
public class CountControl{ jl9hFubwW
private static long lastExecuteTime=0;//上次更新时间 SMonJ;Y
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 i]9C"Kw$L
/** Creates a new instance of CountThread */ $+w:W85B
public CountControl() {} T5|e\<l
public synchronized void executeUpdate(){ rny(8z%Ck-
Connection conn=null; 5:|9pe)
PreparedStatement ps=null; Np7+g`nG
try{ ,Wv+Ek
conn = DBUtils.getConnection(); ~[<C6{
conn.setAutoCommit(false); #zRHYZc'T|
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Wz%H?m:g#
for(int i=0;i<CountCache.list.size();i++){ galzk $D
CountBean cb=(CountBean)CountCache.list.getFirst(); LY-,cXm&|
CountCache.list.removeFirst(); zG{P5@:.R
ps.setInt(1, cb.getCountId()); 9A~w2z\G
ps.executeUpdate();⑴ rtNYX=P
//ps.addBatch();⑵ U$|q]N
} e.\dqt~%y
//int [] counts = ps.executeBatch();⑶ <p/zm}?')
conn.commit(); bMn)lrsX
}catch(Exception e){ -U*J5Q
e.printStackTrace(); Qo32oT[DM
} finally{ ,.Lwtp,n
try{ ;.'?(iEB
if(ps!=null) { 9TX2h0U?
ps.clearParameters(); bgLa`8
ps.close(); IdqCk0lVD
ps=null; C#-HWoSi
} }{y)a<`
}catch(SQLException e){} EHN(K-
DBUtils.closeConnection(conn); OClG dFJ|
} NOg/rDs'{
} 0<7sM#sI!
public long getLast(){ auga`*
return lastExecuteTime; _3(rwD
} !wN2BCSY@
public void run(){ 3\2%i6W6
long now = System.currentTimeMillis(); Ge_fU'F
if ((now - lastExecuteTime) > executeSep) { +5S>"KAUt0
//System.out.print("lastExecuteTime:"+lastExecuteTime); @^T~W^+
//System.out.print(" now:"+now+"\n"); p#).;\M
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); rY6x):sC
lastExecuteTime=now; D=Q.Q
executeUpdate(); >$7x]f
} FQJiLb._Z
else{ %N)B8A9kh
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ]DKRug5
} Q 9fK)j1$
} /78]u^SW
} ((C|&$@M
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 M!+J[q
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类写好了,下面是在JSP中如下调用。 &Ts!#OcB,
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<% GF6 o
CountBean cb=new CountBean(); b"WF]x|^
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); b"uO BB
CountCache.add(cb); n&Ckfo_D
out.print(CountCache.list.size()+"<br>"); f`:GjA,J$
CountControl c=new CountControl(); - w*fS,O
c.run(); U$mDAi$
out.print(CountCache.list.size()+"<br>"); hw,nA2w\
%>