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: pvhN.z
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CountBean.java t&Jrchk
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/* c7A]\1 ~
* CountData.java 9QHV%%
* N#GMvU#R
* Created on 2007年1月1日, 下午4:44 5#~E[dr
* <-"[9 w
* To change this template, choose Tools | Options and locate the template under m1Xc3=Y
* the Source Creation and Management node. Right-click the template and choose -{ES 36
* Open. You can then make changes to the template in the Source Editor. jIck!
*/ S,f:nLT
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package com.tot.count; yOO@v6jO)
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/** RMlx[nsq
* LwcAF g|
* @author E| y
*/ 7X <#
public class CountBean { v+C%t!dx
private String countType; ;%Kh~
int countId; ;]>a7o
/** Creates a new instance of CountData */ 7M<co,"
public CountBean() {} C(n_*8{
public void setCountType(String countTypes){ cUr5x8<W).
this.countType=countTypes; _ ( $U\FW
} 7{p6&xXx
public void setCountId(int countIds){ ~p
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this.countId=countIds; lBLL45%BIN
} y.gjs<y
public String getCountType(){ 10CRgrZ
return countType; H18pVh
} t**MthnW
public int getCountId(){ 5%"sv+iO
return countId; m8Rt>DY
} $Y[C A.F
} eC`G0.op
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CountCache.java >[S\NAE>
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/* > ,x``-
* CountCache.java ?hKpJA'%
* |#zj~>7?
* Created on 2007年1月1日, 下午5:01 5=Il2
* 7`tJ/xtMy;
* To change this template, choose Tools | Options and locate the template under EzU3'x
* the Source Creation and Management node. Right-click the template and choose vf-8DB
* Open. You can then make changes to the template in the Source Editor. ]Xg7XY
*/ 7n7UL0Oc1
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package com.tot.count; ~^l;~&
import java.util.*; x#fv<Cj4
/** ''}2JJU{
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* @author s#FX2r3=Fg
*/ ;N!opg))d<
public class CountCache { 0E#?H0<OeG
public static LinkedList list=new LinkedList(); cUTG!
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/** Creates a new instance of CountCache */ "
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public CountCache() {} B#4'3Y-3
public static void add(CountBean cb){ Y+Cv9U0
if(cb!=null){ HqXS-TG
list.add(cb); $V;0z~&!'
} _Zus4&'
} M=4`^.Ocm
} T!-ly7-`
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CountControl.java >3&9Wbv>
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/* %II o
* CountThread.java /|@~:5R5H
* "Fz1:VV&
* Created on 2007年1月1日, 下午4:57 6Oy6r
* ohi0_mBz
* To change this template, choose Tools | Options and locate the template under #!t6'*
* the Source Creation and Management node. Right-click the template and choose {/i&o
* Open. You can then make changes to the template in the Source Editor. *RFBLCt
*/ r-,u)zf"
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package com.tot.count; uG(XbDZZ1W
import tot.db.DBUtils; EPU3Jban
import java.sql.*; [0lO0ik>G
/** .:=5|0m
* rN'}IS@5
* @author \{={{O
*/ fa!8+kfi
public class CountControl{ >^D5D%"
private static long lastExecuteTime=0;//上次更新时间 FY
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 V^_U=Ed@M
/** Creates a new instance of CountThread */ #lF 2qw
public CountControl() {} G4uA&"OE
public synchronized void executeUpdate(){ ,;n[_f
Connection conn=null; lD$\t/8B
PreparedStatement ps=null; ,,G'Zur7
try{ s3=slWY=
conn = DBUtils.getConnection(); r ?z}TtDp
conn.setAutoCommit(false); S7b7zJ8A
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ~'N+O K
for(int i=0;i<CountCache.list.size();i++){ zZP&`#TAy
CountBean cb=(CountBean)CountCache.list.getFirst(); .>p.k*vU
CountCache.list.removeFirst(); R#!Urhh
ps.setInt(1, cb.getCountId()); 7,Y+FZ
ps.executeUpdate();⑴ `o21f{1]X&
//ps.addBatch();⑵ nGxG!
} T$Z}1e]
//int [] counts = ps.executeBatch();⑶ G)&!f)6
conn.commit(); _po5j;"_O
}catch(Exception e){ rLA^ &P:
e.printStackTrace(); TjOK8
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} finally{ rq:sy=;
try{ `:Zgq+j&
if(ps!=null) { 3|D .r-Q
ps.clearParameters(); f{h2>nEj\
ps.close(); v.c.5@%%o
ps=null; 6E9o*YSk
} h$p}/A
}catch(SQLException e){} oz7=1;r
DBUtils.closeConnection(conn); Qjmo{'d
} zpg512\y
} {FR+a**
public long getLast(){ S 9;FD 3
return lastExecuteTime; Uurpho_~
} =KHX_ib
public void run(){ {Rn*)D9
long now = System.currentTimeMillis(); @_?Uowc8
if ((now - lastExecuteTime) > executeSep) { zKThM#.Wa
//System.out.print("lastExecuteTime:"+lastExecuteTime); #)4p,H
//System.out.print(" now:"+now+"\n"); S~M/!Xb
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ps*iE=D
lastExecuteTime=now; umt(e:3f5
executeUpdate(); $F6GCM3Cx
} ?(M]'ia{
else{ ?O0,)hro
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ~J
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} _)6r@fZ.p
} r(<91~Ww
} 3gv?rJV
//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 r9p ((ir
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类写好了,下面是在JSP中如下调用。 &_' evZ8
V!s#xXD }
<% n>,? V3ly
CountBean cb=new CountBean(); f/{ClP.
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); f'Rq#b@
CountCache.add(cb); CIz_v.&:
out.print(CountCache.list.size()+"<br>"); &UAYYH
CountControl c=new CountControl(); HcpAp]L)
c.run(); $5@[l5cJU;
out.print(CountCache.list.size()+"<br>"); ]ClqX;'weJ
%>