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: yWE\)]9
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CountBean.java ?%Tx%
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/* `Syfl^9B
* CountData.java "5O>egt
* CR%h$+dzy
* Created on 2007年1月1日, 下午4:44 $Bl51VjN
* UnYb}rF#%
* To change this template, choose Tools | Options and locate the template under }4H}*P> +
* the Source Creation and Management node. Right-click the template and choose WBkx!{\z
* Open. You can then make changes to the template in the Source Editor. r]DU
*/ aR('u:@jHi
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package com.tot.count;
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/** o?t H[
* A9u>bWIE7
* @author _~ei1
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*/ O!XSU,
public class CountBean { VBF:MAA
private String countType; G$&jP:2q
int countId; \[.qN
/** Creates a new instance of CountData */ Az8ZA ~Op=
public CountBean() {} QV:> x#=V
public void setCountType(String countTypes){ "::2]3e
this.countType=countTypes; 6NhGTLI
} &GJVFr~z
public void setCountId(int countIds){ F;h^o !W7r
this.countId=countIds; |YyNqwP`,
} un -h%-e|
public String getCountType(){ GEh( pJ
return countType; VKX|0~
} vM5/KrW
public int getCountId(){ e@TwZ6l
return countId; /IJy'@B
} %6 GM[1__
} &z:bZH]DH
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CountCache.java knph549
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/* qGEp 6b H
* CountCache.java QT^b-~^
* svl!"tMXl
* Created on 2007年1月1日, 下午5:01 uL1lB@G@
* K<`Z@f3'w
* To change this template, choose Tools | Options and locate the template under l"nS+z
* the Source Creation and Management node. Right-click the template and choose 3o?eUwI}
* Open. You can then make changes to the template in the Source Editor. X9]} UX
*/ z},\1^[
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package com.tot.count; #{J~
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import java.util.*; N#"l82^H*
/** I^ ![)# FC
* eL(<p]
* @author GN!
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*/ ;DYS1vG o
public class CountCache { *.k*JsU~B
public static LinkedList list=new LinkedList(); % X %zK1
/** Creates a new instance of CountCache */ <f8j^
public CountCache() {} su1fsoL0
public static void add(CountBean cb){ Dv/7w[F
if(cb!=null){ h4|}BGO
list.add(cb); <,n:w[+!`P
} 4m91XD
} V,d\Wk k/
} O_4B>
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CountControl.java <4vCx
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/* 4OgH+<G
* CountThread.java Q>Z~={"
* gH'hA'
* Created on 2007年1月1日, 下午4:57 Xy=ETV%
*
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* To change this template, choose Tools | Options and locate the template under 2sk7E'2(
* the Source Creation and Management node. Right-click the template and choose 7_l
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* Open. You can then make changes to the template in the Source Editor. uyB 2
*/ `NgQ>KV!
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package com.tot.count; v G\J8s
import tot.db.DBUtils; 37a1O>A
import java.sql.*; z+6PVQ
/** A-=hvJ5T
* WH1" HO
* @author C5I7\9F)
*/ uK"FopUJ4i
public class CountControl{ 'F.P93
private static long lastExecuteTime=0;//上次更新时间 sRT H_]c
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 `VO;\s$5j
/** Creates a new instance of CountThread */ n9={D
public CountControl() {} q@[F|EF=
public synchronized void executeUpdate(){ *9kg\#
Connection conn=null; -wV2
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PreparedStatement ps=null; ov,s]g83
try{ hB.8\-}QMq
conn = DBUtils.getConnection(); #\m.3!Hcr
conn.setAutoCommit(false); @!!u>1
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 2672oFD
for(int i=0;i<CountCache.list.size();i++){ ,iP
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CountBean cb=(CountBean)CountCache.list.getFirst(); 2 A!*8w
CountCache.list.removeFirst(); ;NdH]a{
ps.setInt(1, cb.getCountId()); xp95KxHHo
ps.executeUpdate();⑴ S!=R\_{u$
//ps.addBatch();⑵ IBJNs$
} Y8v[kuo7
//int [] counts = ps.executeBatch();⑶ =wDXlAQ
conn.commit(); T:{r*zLSN
}catch(Exception e){ [(#)9/3,
e.printStackTrace(); # M/n\em"X
} finally{ 'hBnV xd&
try{ !JrKTB%
if(ps!=null) { M`'DD-Q
ps.clearParameters(); 8Z9>h:c1
ps.close(); ez[x8M>
ps=null; {._'Q[
} _%D7D~2r|
}catch(SQLException e){} e8xq`:4Y
DBUtils.closeConnection(conn); <%uEWb)
} B47 I?~{
} o(Z~J}l({
public long getLast(){ AkS16A
return lastExecuteTime; 54>0Dv??H
}
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public void run(){ !Ea! "}
long now = System.currentTimeMillis(); -;_"Y]#
if ((now - lastExecuteTime) > executeSep) { AJ*17w
//System.out.print("lastExecuteTime:"+lastExecuteTime); 2h51zG#qd
//System.out.print(" now:"+now+"\n"); 16 `M=R
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); |au`ph5
lastExecuteTime=now; +)q ,4+K%}
executeUpdate(); @#,/6s7?
} FD
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else{ g&2g>]
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ?|W3RK;
} Bt@?l]Y
} Lv%t*s2$/
} E#(e2Z=
//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 4uoZw3O
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类写好了,下面是在JSP中如下调用。 ~s HdOMw
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<% oOI0q_bf
CountBean cb=new CountBean(); z[_Y,I
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ]i`Q+q[
CountCache.add(cb); (b#M4ho*f
out.print(CountCache.list.size()+"<br>"); }'x)e
CountControl c=new CountControl(); Ka(B&.
c.run(); '{
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out.print(CountCache.list.size()+"<br>"); P`Ku.
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