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: )oTEB#J
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CountBean.java H; TmG<S
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/* Mn>dI@/gM
* CountData.java Ou2H~3^PL
* z"}k\B-5
* Created on 2007年1月1日, 下午4:44 jm RYL("
* X]cB`?vR
* To change this template, choose Tools | Options and locate the template under Lj *FKP\{
* the Source Creation and Management node. Right-click the template and choose ol!o8M%Q
* Open. You can then make changes to the template in the Source Editor. KblOP{I
*/ {tOuKnnS
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package com.tot.count; 6xdu}l=%
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/** "x\3`Qk
* *^Zt5 zk
* @author t8i"f L
*/ IS&`O=7
public class CountBean { 0#K@^a
private String countType; W{ eu_
int countId; {Hp?rY@
/** Creates a new instance of CountData */ P|h<|Gcp
public CountBean() {} OOl{
public void setCountType(String countTypes){ Da-F(^E
this.countType=countTypes; kUP[&/Lc
} m6 hA,li
public void setCountId(int countIds){ >-X&/i
this.countId=countIds; FAM`+QtNw
} 7S]
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public String getCountType(){ FVY,CeA.
return countType; W U<#_by
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} H7Y}qP5X
public int getCountId(){ eVU:.fx
return countId; &tWWb`
} R%#c~NOO
} ?b#?Vz
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CountCache.java X'kw5P!sq
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/* ~%#?;hJ
* CountCache.java
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* T"QY@#E
* Created on 2007年1月1日, 下午5:01 I,YGm
* tH_#q"@)
* To change this template, choose Tools | Options and locate the template under IE_@:]K}Ja
* the Source Creation and Management node. Right-click the template and choose 4T^M@+&|
* Open. You can then make changes to the template in the Source Editor. jQb=N%5s
*/ IC}zgvcW
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package com.tot.count; 3M%EK2 ,
import java.util.*; ]m4LY.SQ
/** *r-Bt1
* uXhp+q\
* @author +B8Ut{l
*/ vnN_csJ#^
public class CountCache { UD9h5PgT
public static LinkedList list=new LinkedList(); $35Oyd3s<
/** Creates a new instance of CountCache */ e. [+xOu`
public CountCache() {} b%oma{I=.c
public static void add(CountBean cb){ etTuukq_Z
if(cb!=null){ 50I6:=@\\
list.add(cb); nn=JM7e\9
} 1Rczf (,aT
} fLD9RZ8_
} _eO] awsA
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CountControl.java M2s
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/* |HG%o
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* CountThread.java qS2%U?S7
* 0I#<-9&d-
* Created on 2007年1月1日, 下午4:57 0(i`~g5
* Ce0I8B2y
* To change this template, choose Tools | Options and locate the template under ko5\*!|:lj
* the Source Creation and Management node. Right-click the template and choose 8p5'}Lq
* Open. You can then make changes to the template in the Source Editor. VqbiZOZ@
*/ D>|:f-Z6Z
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package com.tot.count; ITsJjcYw
import tot.db.DBUtils; 1B1d>V$*
import java.sql.*; RF;N]A?*
/** B"qG-ci
* 5=?&q 'i
* @author ?DRC!
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*/ ]!A;-m
public class CountControl{ K[ \z'9Q
private static long lastExecuteTime=0;//上次更新时间 JBwTmOvQ
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 =?f}h{8x>
/** Creates a new instance of CountThread */ xJ"KR:CD>
public CountControl() {} {[s<\<~B*
public synchronized void executeUpdate(){ cYp}$
Connection conn=null; N!m%~},s//
PreparedStatement ps=null; V`H#|8\i
try{ r[,KE.^6~#
conn = DBUtils.getConnection(); @"~\[z5
conn.setAutoCommit(false); G`
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); lyi}q"Kn*;
for(int i=0;i<CountCache.list.size();i++){ !e7vc[N
CountBean cb=(CountBean)CountCache.list.getFirst(); %b*%'#iK
CountCache.list.removeFirst(); JJ+<?CeHD
ps.setInt(1, cb.getCountId()); [-CG&l2?L
ps.executeUpdate();⑴ I#Bz
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//ps.addBatch();⑵ g@U#Y#b@"
} o}%fs
*
//int [] counts = ps.executeBatch();⑶ `j(+Y
conn.commit(); T2->
}catch(Exception e){ asF-mf;D
e.printStackTrace(); <G&v
} finally{ 869`jA&7"
try{ c !;wp,c
if(ps!=null) { x:bYd\
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ps.clearParameters(); 3Yf$WE8#l
ps.close(); gON6jnDO
ps=null; GmHsO/
} |`okIqp
}catch(SQLException e){} Q?tV:jogY
DBUtils.closeConnection(conn); p']AXJ`Z
} ]S:@=9JB'
} [_0g^(`
public long getLast(){ j~{2fd<>
return lastExecuteTime; i f"v4PHq
} RasoOj$
public void run(){ 4w?7AI]Ej
long now = System.currentTimeMillis(); NV gLq@F
if ((now - lastExecuteTime) > executeSep) { t,+S~Cj|
//System.out.print("lastExecuteTime:"+lastExecuteTime); iWCV(!
//System.out.print(" now:"+now+"\n"); s +GF-kJ*
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); IN"vi|1
lastExecuteTime=now; ##5/%#eZ
executeUpdate(); YNXk32@j@e
} D=\|teA&
else{ 6a@~;!GlI
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); BNy"YK$
} C1/jA>XW
} O<3,n;56Z
} wY95|QS
//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 d"78:+
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类写好了,下面是在JSP中如下调用。 zb" hy"hKw
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<% {eXYl[7n
CountBean cb=new CountBean(); moR]{2Cd{
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); vh HMxOZ;
CountCache.add(cb); Dr1F|[
out.print(CountCache.list.size()+"<br>"); yRYWx` G
CountControl c=new CountControl(); s]N-n?'G"
c.run(); uaKB
out.print(CountCache.list.size()+"<br>"); 3wE8y&
%>