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: WUZusW5s
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CountBean.java *$Bx#0J8
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/* Sw%^&*J
* CountData.java ~Cm_=[
* l 'm!e '7_
* Created on 2007年1月1日, 下午4:44 V-IXtQR
* ?`lIsd
* To change this template, choose Tools | Options and locate the template under =[`B -?
* the Source Creation and Management node. Right-click the template and choose Igrr"NuDZ
* Open. You can then make changes to the template in the Source Editor. .liVlo@
*/ G*JasHFs
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package com.tot.count; 8k vG<&D
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/** E:(DidSE@
* c<fl6o)
* @author `r+zNJ@q
*/ 5LM Ay"
public class CountBean { 8Q4yllv4
private String countType; Y,n&g45m
int countId; QbrR=[8b
/** Creates a new instance of CountData */ {Dup k0'(
public CountBean() {} v)1@Ew=Y%
public void setCountType(String countTypes){ n%X5TJE
this.countType=countTypes; > &tmdE
} }6b" JoC
public void setCountId(int countIds){ bWv2*XC
this.countId=countIds; b
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} rU/8R'S
public String getCountType(){ k}18
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return countType; S+2we
} hX4V}kj
public int getCountId(){ "!,)Pv
return countId; +@G#Z3;l!
} XN|[8+#U<@
} ]?c9;U
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CountCache.java eU(cn8/}
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/* mM(Z8PA9-
* CountCache.java a1#",%{I
* 6 H{G$[2
* Created on 2007年1月1日, 下午5:01 ?hBj q
* <*_DC)&79
* To change this template, choose Tools | Options and locate the template under !KC4[;Y
* the Source Creation and Management node. Right-click the template and choose yo^M>^P\N
* Open. You can then make changes to the template in the Source Editor. Q{=DLm`
*/ ({$>o] <h
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package com.tot.count; me@k~!e"z
import java.util.*; Fe L !%z
/** s+0n0C
* aE(DNeG-H
* @author U2G[uDa;
*/ YgV" *~
public class CountCache { }y>/#]X
public static LinkedList list=new LinkedList(); ?+_Y!*J2b
/** Creates a new instance of CountCache */ GahIR9_2
public CountCache() {} _J&IL!S2
public static void add(CountBean cb){ VPvQ]}g6k
if(cb!=null){ Qa#Em1co
list.add(cb); q~. .Z Y`7
} ;q?WU>c{?
} gY {/)"
} ovk^
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CountControl.java P" aw--f(
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/* xey?.2K1A
* CountThread.java ^XT;n
* *4y0Hq
* Created on 2007年1月1日, 下午4:57 *RD<*l
* NCp]!=uM;
* To change this template, choose Tools | Options and locate the template under RPw1i*
* the Source Creation and Management node. Right-click the template and choose jO.c>C[?
* Open. You can then make changes to the template in the Source Editor. mXT{c=N)w
*/ .A F94OlE/
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package com.tot.count; 9Xe|*bT
import tot.db.DBUtils; yRWZ/,9x
import java.sql.*; iw^"?:'%
/** 04c`7[
* \7WZFh%:
* @author {!*dk
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*/ ~.Er
public class CountControl{ H,(4a2zx
private static long lastExecuteTime=0;//上次更新时间 OzV|z/R2'
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 v*&WqVg
/** Creates a new instance of CountThread */ 7I0K=
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public CountControl() {} .-:@+=(
public synchronized void executeUpdate(){ 8bX?HeYrr
Connection conn=null; Na.)!h_Kn'
PreparedStatement ps=null; ;F:Qz^=.a
try{ 7Ga'FT.F
conn = DBUtils.getConnection(); ,-V7~gM%}
conn.setAutoCommit(false); k&= iye(
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ,#.9^J
for(int i=0;i<CountCache.list.size();i++){ 7#sb},J{
CountBean cb=(CountBean)CountCache.list.getFirst(); VrKFpFd
CountCache.list.removeFirst(); s;,ulME
ps.setInt(1, cb.getCountId()); CTZ#QiNP
ps.executeUpdate();⑴ g7r0U6Y
//ps.addBatch();⑵ i}kMo@
} oF.H?lG7`
//int [] counts = ps.executeBatch();⑶ y^:6D(SR
conn.commit(); J5zu}U?
}catch(Exception e){ i> PKE.
e.printStackTrace(); =UV=F/Af^
} finally{ 7jPn6uz>w
try{ J1d|L|M
if(ps!=null) { R]y9>5 'U
ps.clearParameters(); VMW<?V
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ps.close(); IWnyqt(k
ps=null; ~p$ncIr2Q
} vb2aj!8_?
}catch(SQLException e){} HE*P0Yf=
DBUtils.closeConnection(conn); [KsVI.gn
} 7J$Yd976
} ?sbM= oo
public long getLast(){ l`vr({A
return lastExecuteTime; &$. x1$%
} 0zqTX< A
public void run(){ `bEum3l\6]
long now = System.currentTimeMillis(); eo'C)j# U
if ((now - lastExecuteTime) > executeSep) { 5U.,iQ(d
//System.out.print("lastExecuteTime:"+lastExecuteTime); 5h>t4 [~
//System.out.print(" now:"+now+"\n"); G9jlpf5>
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 6 WEu(}=
lastExecuteTime=now; 4W+%`x_U]
executeUpdate(); %M;{+90p>t
} ` L?9-)m<f
else{ -u%'u~s
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); KDy:A>_ G"
} ;@I}eZ,f$
} O:(%m
} &Qq4xn+J
//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 OvW/{
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类写好了,下面是在JSP中如下调用。 ^1NtvQe@Y\
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<% e,Fe,5E&g
CountBean cb=new CountBean(); m&Lc."
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Id'@!U:NA
CountCache.add(cb); d
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out.print(CountCache.list.size()+"<br>"); *oz=k
CountControl c=new CountControl(); 9C)w'\u9+
c.run(); Eb=;D1)y]
out.print(CountCache.list.size()+"<br>"); YP vg(T
%>