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: FC+K2Yf1=0
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CountBean.java q@1!v
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/* G>f-w F6
* CountData.java 6U)Lhf\'o
* sI4Ql0[
* Created on 2007年1月1日, 下午4:44 8t3@Hi
* VOH.EK?5
* To change this template, choose Tools | Options and locate the template under $[txZN
* the Source Creation and Management node. Right-click the template and choose os*QWSs
* Open. You can then make changes to the template in the Source Editor. %cJ]Ds%V
*/ +~mBo+ ,
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package com.tot.count; ~t\Hb8o
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/** =+ `I%>wc
* z17
* @author 99 /fI
*/ Q?rb(u(
public class CountBean { g(m3
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private String countType; b$)b/=2
int countId;
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/** Creates a new instance of CountData */ |mvy@hm
public CountBean() {} :9!?${4R
public void setCountType(String countTypes){ CI$pPY<u1
this.countType=countTypes; ?h4-D:!$L
} $>zLa_cn|
public void setCountId(int countIds){ )P>Cxzs
this.countId=countIds; oyV@BHJO@
} m5Gt8Z 6a
public String getCountType(){ U{n< n8
return countType; ukBj@.~
} ,W"Q)cL
public int getCountId(){ (5S(CYls
return countId; TGx:#x*k
} biFy*+|
} Xao
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CountCache.java ^Z]1Z
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/* Dn;6O
* CountCache.java JI-q4L|
* !X721lNP
* Created on 2007年1月1日, 下午5:01 qXO@FW]
* G3vKA&KZ
* To change this template, choose Tools | Options and locate the template under En%PIkxeR
* the Source Creation and Management node. Right-click the template and choose vB >7W
* Open. You can then make changes to the template in the Source Editor. M; *f(JY$
*/ 7+';&2M)n~
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package com.tot.count; J5PXmL
import java.util.*; R /J@XP
/** xKIzEN
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* "C 7-^R#
* @author 1B+uv0lA
*/ I\J^@&JE
public class CountCache { 1?s]nU
public static LinkedList list=new LinkedList(); >-fOkOWXy
/** Creates a new instance of CountCache */ DEEQ/B{
public CountCache() {} pX3Q@3,$
public static void add(CountBean cb){ j8kax/*[
if(cb!=null){ m~a'
list.add(cb); CC,_I>t
} gB1w,96J
} 0 =#)-n
} K~Lh'6
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CountControl.java Z}74%
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/* <RzGxhT
* CountThread.java uN1(l}z$
* (}1 gO
* Created on 2007年1月1日, 下午4:57 $S{B{FK
* Cz@[l=-T7
* To change this template, choose Tools | Options and locate the template under zFVNb
* the Source Creation and Management node. Right-click the template and choose QRbiO
* Open. You can then make changes to the template in the Source Editor. .{U@Hva_K
*/ D90m..\w
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package com.tot.count; (3kz(6S
import tot.db.DBUtils; wxw3t@%mNm
import java.sql.*; Y]
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/** R:49Gn:F
* .|=~x3mPw
* @author D|`O8o?)
*/ E#'JYz@
public class CountControl{ 2xy
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private static long lastExecuteTime=0;//上次更新时间 {s^vAD<~x3
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 EXt?xiha?
/** Creates a new instance of CountThread */ 78'HE(*
public CountControl() {} rGjP|v@3^
public synchronized void executeUpdate(){ d&mSoPf
Connection conn=null; r)S tp`p
PreparedStatement ps=null; $Pw@EC]
try{ t[>y=89
conn = DBUtils.getConnection(); 05_aL` &eb
conn.setAutoCommit(false); D
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); AUCk]
for(int i=0;i<CountCache.list.size();i++){ ID+o6/V8
CountBean cb=(CountBean)CountCache.list.getFirst(); 92y<E<n
CountCache.list.removeFirst(); }O=QXIF5
ps.setInt(1, cb.getCountId()); %"#%/>U4
ps.executeUpdate();⑴ d4'*K1m
//ps.addBatch();⑵ p6=L}L
} _
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//int [] counts = ps.executeBatch();⑶ Skm$:`u;
conn.commit(); =*K~U# uoC
}catch(Exception e){ 46U?aHKW@|
e.printStackTrace(); a>w@9
} finally{ k[6%+
try{ RZwjc<T
if(ps!=null) { 'rWu}#Nb
ps.clearParameters(); +C`h*%BW
ps.close(); j+B+>r^
ps=null; mc{gcZIm
} aI8k:FK"
}catch(SQLException e){} n.}A
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DBUtils.closeConnection(conn); / {|<3CEe
} A\{dq:
} ED9uKp<Wbv
public long getLast(){ 6O|B'?]Pf
return lastExecuteTime; Jxyeh1zqB
} p8yn? ~]^
public void run(){ :wlX`YW+e
long now = System.currentTimeMillis(); N
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if ((now - lastExecuteTime) > executeSep) { T(<
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//System.out.print("lastExecuteTime:"+lastExecuteTime); y,I ?3p|S
//System.out.print(" now:"+now+"\n"); ;W ZA
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); N#C"@,}Y
lastExecuteTime=now; CYIp 3D'k
executeUpdate(); 41\r7
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} >G4EiJS
else{ <:v2N/i
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); )9(Mt_
} () l#}H`m
} ql
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} `R}q&|o7<
//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 ^]iIvIp
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类写好了,下面是在JSP中如下调用。 desrKnY
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<% z|';Y!kQ
CountBean cb=new CountBean(); (eTe`
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); [^iQE
CountCache.add(cb); ]{tnNr>mv
out.print(CountCache.list.size()+"<br>"); RTHe#`t
CountControl c=new CountControl(); D%tcYI(
c.run(); 1M%'Xe7
out.print(CountCache.list.size()+"<br>"); 7/p&]0w
%>