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: PlU*X8
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CountBean.java *rM^;4Zt
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/* ?Nup1!D
* CountData.java ' KWyx
* 09X01X[
* Created on 2007年1月1日, 下午4:44 ;X8yFq
* <6EeD5{*
* To change this template, choose Tools | Options and locate the template under 14Xqn8uOW
* the Source Creation and Management node. Right-click the template and choose i2@VB6]?
* Open. You can then make changes to the template in the Source Editor. \s/s7y6b+
*/ 3C?f(J}
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package com.tot.count; WQ~;;.v#
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/** nG,A@/N
* k52/w)Ro,$
* @author 8UW^"4
*/ NaPt"G
public class CountBean { WzPTFw[
private String countType; KX76UW
int countId; o>).Cj
/** Creates a new instance of CountData */ H35S#+KX
public CountBean() {} >sfRI]OG
public void setCountType(String countTypes){ &R[ Mc-2
this.countType=countTypes; h hG4-HD
} E=jNi
public void setCountId(int countIds){ @XgKYm
this.countId=countIds; E[2m&3&
} OP~HdocB
public String getCountType(){ aO]ZZleNS
return countType; =+/eLKG
} 9*2[B"5
public int getCountId(){ VeGL)
return countId; "8c@sHk(w
} oo,uO;0G
} gi(H]|=a
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CountCache.java _4rFEYz$d
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/*
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* CountCache.java !2 LCLN\
* ^M3~^lV
* Created on 2007年1月1日, 下午5:01 V `b2TS
* W0(_~
* To change this template, choose Tools | Options and locate the template under 3[\iQ*d }B
* the Source Creation and Management node. Right-click the template and choose M9Cv
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* Open. You can then make changes to the template in the Source Editor. L;
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*/ b o0^3]Z
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package com.tot.count; B268e
import java.util.*; Ager$uC
/** U1@IX4^2`
* -u&6X,Oq\u
* @author VGfMN|h
*/ (hTCK8HK
public class CountCache { +!k&Yje
public static LinkedList list=new LinkedList(); K\>tA)IPSV
/** Creates a new instance of CountCache */ N/]o4o
public CountCache() {} %u`8minCt
public static void add(CountBean cb){ iDN;m`a
if(cb!=null){ AK&S5F>D+B
list.add(cb); J cg,#@
} pwO>h>ik
} K)-U1JE7
} ;>506jZ
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CountControl.java jYx38_5e
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/* W@ T~ly;e*
* CountThread.java *n;!G8\
* ~1cnE:x;V
* Created on 2007年1月1日, 下午4:57 w ihH?~]
* 3j,Q`+l/6d
* To change this template, choose Tools | Options and locate the template under 0T@ Zb={
* the Source Creation and Management node. Right-click the template and choose Yb:\a/ y
* Open. You can then make changes to the template in the Source Editor. P.6nA^hXB
*/
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package com.tot.count; 4Yxo~ m(
import tot.db.DBUtils; 0FGe=$vD
import java.sql.*; UV5Ie!\nm
/** $>*3/H
* MJ7 Y#<u
* @author WEFlV4/
*/ _= +V/=
public class CountControl{ -0?~
private static long lastExecuteTime=0;//上次更新时间 Kpb#K[(]&
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 W^fuScG)c
/** Creates a new instance of CountThread */ kz{/(t
public CountControl() {} g$(
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public synchronized void executeUpdate(){ 0%,!jW{`
Connection conn=null; i\1TOP|h
PreparedStatement ps=null; #rxVd
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try{ ([
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conn = DBUtils.getConnection(); 0zo?eI
conn.setAutoCommit(false); {8 8 )~
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); OTC!wI
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for(int i=0;i<CountCache.list.size();i++){ .^N/peUq
CountBean cb=(CountBean)CountCache.list.getFirst(); g$HwxA9Gp/
CountCache.list.removeFirst(); P9=?zh6G.
ps.setInt(1, cb.getCountId()); HkQ*y$$
ps.executeUpdate();⑴ UQ'\7OS
//ps.addBatch();⑵ +lJG(Qd
} }Mo=PWI1?
//int [] counts = ps.executeBatch();⑶ f-}[_Y%;
conn.commit(); -cZDGt
}catch(Exception e){ yMyE s 8
e.printStackTrace(); f&}k^>N#3
} finally{ [E+$?a=
try{ K/A*<<r
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if(ps!=null) { $}lbT15a
ps.clearParameters(); ?dD&p8{
ps.close(); <.pU,T/
ps=null; GN-mrQo
} ;FBUwR}
}catch(SQLException e){} kjEEuEv
DBUtils.closeConnection(conn); g) p,5BADm
} ()K " c#
} 7nHF@Y|*"
public long getLast(){ *F
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return lastExecuteTime; 1c<=A!"{
} +
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public void run(){ 8CnRi
long now = System.currentTimeMillis(); $Z|ffc1
if ((now - lastExecuteTime) > executeSep) { 1&^MfP}
//System.out.print("lastExecuteTime:"+lastExecuteTime); ojQI7 Uhw
//System.out.print(" now:"+now+"\n"); _7IKzUn9g[
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); P8^hBv*
lastExecuteTime=now; 9;Itqe{8w
executeUpdate(); d*A*y ^OD
} 4D['^q
else{ (7XCA,KTGI
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); A$#p%yb
}
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} }@Ge}9$h
} g0>,%b
//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 43={Xy
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类写好了,下面是在JSP中如下调用。 {.Z}5K
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<% xqC+0{]y
CountBean cb=new CountBean(); f8M$45A'
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); +<xQM h8
CountCache.add(cb); Mu{;vf|j
out.print(CountCache.list.size()+"<br>"); *g y{]
CountControl c=new CountControl(); IX*idcxR
c.run(); 2P/K
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out.print(CountCache.list.size()+"<br>"); ]xX$<@HR
%>