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: KcvstC`
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CountBean.java N<PDQ
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/* ;=p3L<~c`K
* CountData.java sg8[TFX@Z
* vc0LV'lmg
* Created on 2007年1月1日, 下午4:44 ~ \]?5
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* w*M&@+3I
* To change this template, choose Tools | Options and locate the template under (Z0_e&=*
* the Source Creation and Management node. Right-click the template and choose AP:Q]A6}
* Open. You can then make changes to the template in the Source Editor. '^.`mT'P
*/ bu9.HvT'
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package com.tot.count; yAiO._U
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/** a$j ~YUG_
* Kl,NL]]4*5
* @author rQxiG[0
*/ Bd]k]v+
public class CountBean { zM,r0Z
private String countType; '451H3LC0
int countId; H$+@O-
/** Creates a new instance of CountData */ ^TtL-|I
public CountBean() {} ]"&](e6*
public void setCountType(String countTypes){ W,|+Dl
this.countType=countTypes; g/FZ?Wo
} YF)]B |I
public void setCountId(int countIds){ o1vK2V
this.countId=countIds; [!De|,u(^
} Cyos*
public String getCountType(){ XEnu0gr
return countType; [#9i@40
} E.Q]X]q
public int getCountId(){ t/}NX[q
return countId; DXo]O}VF
} u0GHcpOm
} au04F]-|j8
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CountCache.java -@e2/6Oi
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/* B>W8pZu-J
* CountCache.java J#48c'
* x_/}R3d
* Created on 2007年1月1日, 下午5:01 _1NK9dp:
* AN:yL
a!
* To change this template, choose Tools | Options and locate the template under 7o0zny3?
* the Source Creation and Management node. Right-click the template and choose \ )=WA!
* Open. You can then make changes to the template in the Source Editor. )S
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*/ >MGWN
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package com.tot.count; n m<?oI*\
import java.util.*; f"KrPx!^b
/** 1$8@CT^m
* e{7\pQK
* @author W&=OtN
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*/ 'L7qf'RV
public class CountCache { K Ax=C}9
public static LinkedList list=new LinkedList(); .07`nIs"
/** Creates a new instance of CountCache */ IH;sVT$M
public CountCache() {} D3yTN"
public static void add(CountBean cb){ i1|>JM[V
if(cb!=null){ dYwkP^KB
list.add(cb); #n'.a1R
} >UMxlvTg&
} {$,\Qg
} N(Ru/9!y"
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CountControl.java oX;.v9a
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/* %W"u4
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* CountThread.java 4%^z=%
* u0h%4f!X
* Created on 2007年1月1日, 下午4:57 oGRk/@
* TIKkS*$
* To change this template, choose Tools | Options and locate the template under B=!!R]dxA
* the Source Creation and Management node. Right-click the template and choose g#=<;X2
* Open. You can then make changes to the template in the Source Editor. :YI5O/gsk?
*/ x-m*p^}
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package com.tot.count; >`\.i,X.D
import tot.db.DBUtils; +Yc^w5 !(
import java.sql.*; AP=h*1udk
/** >jX"
*
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* @author nbF<K?
*/ nwU],{(Hgr
public class CountControl{ c,xdkiy3
private static long lastExecuteTime=0;//上次更新时间 `qc"JB
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 nzC *mPX8
/** Creates a new instance of CountThread */ rO7_K>g?
public CountControl() {} w'K7$F51
public synchronized void executeUpdate(){ "pM>TMAE
Connection conn=null; w$:\!FImx
PreparedStatement ps=null; "[N2qJ}p
try{ d}\]!x3t
conn = DBUtils.getConnection(); m$p}cok#+S
conn.setAutoCommit(false); _y~6b{T
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); >qo!#vJc
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for(int i=0;i<CountCache.list.size();i++){ x95s%29RS
CountBean cb=(CountBean)CountCache.list.getFirst(); NPK;
CountCache.list.removeFirst(); %JM$]
ps.setInt(1, cb.getCountId()); qWhW4$7x
ps.executeUpdate();⑴ CPJ21^
//ps.addBatch();⑵ ZaYiby@Ci
} SE+hB
//int [] counts = ps.executeBatch();⑶ zR<{z
conn.commit(); X5iD<Lh
}catch(Exception e){ _LHbP=B
e.printStackTrace(); SaXt"Ju,AH
} finally{ _d]{[&
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try{ 5p#0K@`n/
if(ps!=null) { 0`x>p6.)G
ps.clearParameters();
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ps.close(); g>VtPS5 y
ps=null; m^QoB
} R4'.QZ-x
}catch(SQLException e){} L<!h3n
DBUtils.closeConnection(conn); p& _Z}Wv
} ';3>rv_
} LO_Xrj
public long getLast(){ @} r*KF-
return lastExecuteTime; M7/5e3
} E{T3Xwg
public void run(){ v@{y}
long now = System.currentTimeMillis(); mW"e
if ((now - lastExecuteTime) > executeSep) { CH4Nz'X2
//System.out.print("lastExecuteTime:"+lastExecuteTime); 2H`r:x<Z-
//System.out.print(" now:"+now+"\n"); <.ZIhDiEl
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); zeMV_rW~
lastExecuteTime=now; i3)3.WK^
executeUpdate(); MGF!ZZ\
} e8`d<U
else{ -U2Su|:\N8
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); spA|[\Nl
} oO
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} ;l;jTb ^l
} Vx!ZF+
//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 xQZOGq
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类写好了,下面是在JSP中如下调用。 e)HFI|>
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<% W>' DQB
CountBean cb=new CountBean(); YMw,C:a4
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); vVB WhY]
CountCache.add(cb); eYv^cbO@:
out.print(CountCache.list.size()+"<br>"); 7oE:]
CountControl c=new CountControl(); yFAUD
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c.run(); w?D=
out.print(CountCache.list.size()+"<br>"); Z%?>H iy'o
%>