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: q 'a
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CountBean.java X0+fsf<H}
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/* 0i8hI6d
* CountData.java oXt,e
* hsG#6?l3
* Created on 2007年1月1日, 下午4:44 rt +..t\
* DV]7.Bm
* To change this template, choose Tools | Options and locate the template under l??;3kh1
* the Source Creation and Management node. Right-click the template and choose |__=d+M'
* Open. You can then make changes to the template in the Source Editor. .`Zf}[5[
*/ <;t)6:N\
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package com.tot.count; ftavbNR`W
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/** -,":5V26
* ]y)Q!J )Q
* @author baoD(0d
*/ N 6O8Wn
public class CountBean { dd7 =)XT+
private String countType; y9;#1:ic
int countId; qJT0Y/l:(
/** Creates a new instance of CountData */ YY4-bNj[p
public CountBean() {} 7TX,T|>9
public void setCountType(String countTypes){ VLg
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this.countType=countTypes; W*xX{$NL
} >^"BEG9i:
public void setCountId(int countIds){ M`,XyIn
this.countId=countIds; "!Rw)=7O
} IdRdW{o
public String getCountType(){ ^!;=6}Y R
return countType; bYh9sO/l
} [H"#7t.V-~
public int getCountId(){ )Z@-DA*Q-
return countId; g"!\\:M
} {lz G*4?
} [~k]{[NJ
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CountCache.java z]$j7 dp
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/* <-jGqUN_I
* CountCache.java fjDpwb:x)
* /k"hH\Pp
* Created on 2007年1月1日, 下午5:01 8!h'j
* ._p""'Sa
* To change this template, choose Tools | Options and locate the template under 5>ST"l_ca
* the Source Creation and Management node. Right-click the template and choose O'}llo
* Open. You can then make changes to the template in the Source Editor. ?9u4a_x
*/ dTD5(}+J
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package com.tot.count; ]?9[l76O7
import java.util.*; %XXkVK`
/** H^CilwD158
* {B yn{?w
* @author '%3{jc-}
*/ LnMwx#^*
public class CountCache { ,\hYEup
public static LinkedList list=new LinkedList(); _Nu`)m
/** Creates a new instance of CountCache */ I Ru$oF}
public CountCache() {} }NX\~S"
public static void add(CountBean cb){ liNON
if(cb!=null){ H$-$2?5
list.add(cb); 1BD6l2y
} +
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} VvgN3e[
} 2%]hYr;
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CountControl.java x|apQ6
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/* ^)cM&Bxt%
* CountThread.java Jc~E"x
* J7a-CI_Tf
* Created on 2007年1月1日, 下午4:57 ~!
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* .wFU:y4r
* To change this template, choose Tools | Options and locate the template under )Ul&1UYA
* the Source Creation and Management node. Right-click the template and choose ye r>
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* Open. You can then make changes to the template in the Source Editor. .g-3e"@
*/ uU+s!C9r
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package com.tot.count; j3P RAe
import tot.db.DBUtils; Rx.
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import java.sql.*; wd`R4CKhP]
/** %^^h) Wy}
* \FI^Vk
* @author |z7dRDU}]
*/ c=t*I0-OVS
public class CountControl{ Z oTNm
private static long lastExecuteTime=0;//上次更新时间 ur xqek
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 *Pb.f
/** Creates a new instance of CountThread */ pB'x_z
public CountControl() {} 5K(n3?1z)
public synchronized void executeUpdate(){ O`[]xs
Connection conn=null; *#ompm
PreparedStatement ps=null; s4IKSX
try{ ip5u_Xj?
conn = DBUtils.getConnection(); "X?LAo
conn.setAutoCommit(false); !\w\ ]7ls
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); @dhH;gt.I
for(int i=0;i<CountCache.list.size();i++){ H5q:z=A
CountBean cb=(CountBean)CountCache.list.getFirst(); O&P>x#w
CountCache.list.removeFirst(); :Ba-u
ps.setInt(1, cb.getCountId()); OX,F09.C
ps.executeUpdate();⑴ &@'V\5G
//ps.addBatch();⑵ cJ4S!
} )K.R\]XR
//int [] counts = ps.executeBatch();⑶ CI1m5g [P
conn.commit(); L9'-
}catch(Exception e){ cd"wNH-
e.printStackTrace(); w})NmaT;YF
} finally{ `hF;$
try{ g Np-f
if(ps!=null) { l_sg)Vr/b
ps.clearParameters(); v =bv@c
ps.close(); >\-3P$
ps=null; Hrv),Ce
} wL|7mMM,
}catch(SQLException e){} hd=j56P5P
DBUtils.closeConnection(conn); = P8~n2V
} &.*T\3UO
} <\xQ7|e
public long getLast(){ @{de$ODu
return lastExecuteTime; \1khyF'
} ]*h&hsS0
public void run(){ |x[$3R1@
long now = System.currentTimeMillis();
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if ((now - lastExecuteTime) > executeSep) { HU.1":.;
//System.out.print("lastExecuteTime:"+lastExecuteTime); <lX:eR1
//System.out.print(" now:"+now+"\n"); R^?PAHE7
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); j<|6s,&
lastExecuteTime=now; =tP$re";o
executeUpdate(); I1J)#p%H.
} R mgxf/
else{ 1#kawU6[]
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); $ACe\R/%
} >|S>J+(
} V?WMj
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} 6 cr^<]v !
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 Uc>LFX&
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类写好了,下面是在JSP中如下调用。 |<2JQ[]
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<% ?-M)54b\
CountBean cb=new CountBean(); 8ST~$!z$
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 8s&2gn1
CountCache.add(cb); | )S{(#k
out.print(CountCache.list.size()+"<br>"); |<7i|J
CountControl c=new CountControl(); >T$7{
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c.run(); 3# :EK
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out.print(CountCache.list.size()+"<br>"); <X9T-b"$h
%>