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: sv.?C pE
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CountBean.java |2Y/l~
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/* #ZC9=
* CountData.java [Ot<8)Jm
* &s(mbpV
* Created on 2007年1月1日, 下午4:44 c(kYCVc
* 8 7z]qE
* To change this template, choose Tools | Options and locate the template under j0b>n#e7
* the Source Creation and Management node. Right-click the template and choose kt#t-N;}x
* Open. You can then make changes to the template in the Source Editor. 8U%y[2sT
*/ +h)1NX;o1
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package com.tot.count; 0;L.h|R T(
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/** :anR/
* $qR<_6j
* @author Z?<&@YQS
*/ uhm3}mWv
public class CountBean { h:AB`E1
private String countType; YfstE3BV
int countId;
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/** Creates a new instance of CountData */ P8X59^cJ
public CountBean() {} ei82pLM
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public void setCountType(String countTypes){ JA$RY
this.countType=countTypes; S-[S?&c`
} RhWW61!"
public void setCountId(int countIds){ g5;Ig
this.countId=countIds; zEKVyZd*{
} m++=FsiX=
public String getCountType(){ `J$7X
return countType; M1q_gHA
} KJ 7-Vl>
public int getCountId(){ `)tIXMn
return countId; o3X0c6uU
} NdmwQJ7e"
} )*L=$0R
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CountCache.java c
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/* <2e[; $
* CountCache.java eUKl(
* g_JSgH!4
* Created on 2007年1月1日, 下午5:01 Ie[DTy
* ,B:r^(}0j
* To change this template, choose Tools | Options and locate the template under 2BO&OX|X
* the Source Creation and Management node. Right-click the template and choose xC9?Wt'
* Open. You can then make changes to the template in the Source Editor. Nwg?(h#
*/
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package com.tot.count; @e-2]z
import java.util.*; #]h&GX
/** 6@VgLa,
* cAn_:^
* @author A[`2Mnj
*/ !-m 'diE
public class CountCache { &
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public static LinkedList list=new LinkedList(); IQWoK"B
/** Creates a new instance of CountCache */ K8W99:v
public CountCache() {} LMNmG]#!
public static void add(CountBean cb){ PVSz%"
if(cb!=null){ b"nD5r
list.add(cb); }LY)FT4n
} } J`cRDO
} O Cnra
} \[d~O>k2
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CountControl.java >uxAti\
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/* !ou;yE&<,
* CountThread.java tC5>K9Ed
* (W.G&VSn)
* Created on 2007年1月1日, 下午4:57 4N5\sdi
* *#1J
* To change this template, choose Tools | Options and locate the template under nE56A#,Q,
* the Source Creation and Management node. Right-click the template and choose AYAbq}'Yt
* Open. You can then make changes to the template in the Source Editor. "H]R\xp
*/ mRy0zN>?
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package com.tot.count; rYM@e
import tot.db.DBUtils; }S;A%gYm
import java.sql.*; w3&L 6|,
/** :m<#\!?
* |_hIl(6F5N
* @author &YBZuq2?
*/ kz G W/
public class CountControl{ abp\Ih^b
private static long lastExecuteTime=0;//上次更新时间 "-P z2QJY
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 V@nZ_.
/** Creates a new instance of CountThread */ L9]d$ r"
public CountControl() {} Fw8b^ew
public synchronized void executeUpdate(){ ;u=%Vn"2a
Connection conn=null; qYQ
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PreparedStatement ps=null; @SI,V8i
try{ !R![:T\,
conn = DBUtils.getConnection(); QZ+G2$
conn.setAutoCommit(false); /I:&P Pff
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); YRCOh:W*
for(int i=0;i<CountCache.list.size();i++){ RN$>!b/
CountBean cb=(CountBean)CountCache.list.getFirst(); 6m@B.+1
CountCache.list.removeFirst(); Ed+jSO0
ps.setInt(1, cb.getCountId()); lx7]rkWo|a
ps.executeUpdate();⑴ e|q~t
{=9S
//ps.addBatch();⑵ ornU8H`
} V{fG~19
//int [] counts = ps.executeBatch();⑶ j@{ B 8
conn.commit(); TiR00#b
}catch(Exception e){ . I."q
e.printStackTrace(); OlgM7Vrl
} finally{ m;0ZV%c*j
try{ 6ld /E
if(ps!=null) { j.[W] EfL~
ps.clearParameters(); /6Kx249Dw
ps.close(); 7.]H9
ps=null; P26"z))~d
} `fE'$2
}catch(SQLException e){} i1K$~
DBUtils.closeConnection(conn); f`iDF+h<6
} !JBj%| !
} u'^kpr`y
public long getLast(){ MY^o0N
return lastExecuteTime; ;0`IFtz
} >I',%v\?@
public void run(){ biS{.
long now = System.currentTimeMillis(); HBZ6 Pj
if ((now - lastExecuteTime) > executeSep) { Ko)f:=Qo
//System.out.print("lastExecuteTime:"+lastExecuteTime); 7EVB|gTp
//System.out.print(" now:"+now+"\n"); bn7g!2
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); nb ?(zDJ8
lastExecuteTime=now; cI&XsnY
executeUpdate(); Gzs$0Ki=
} Y[W :Zhl;
else{ 50`|#zF^#
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); RRQIlI<
} nTD4^'
} 57q?:M=^
} 8c>xgFWp9
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 C;%dZ
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类写好了,下面是在JSP中如下调用。 7-0j8$`
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<% y;(G%s1
CountBean cb=new CountBean(); ~z,qr09
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); q,> C^p|2b
CountCache.add(cb); Hv2[=e lc
out.print(CountCache.list.size()+"<br>"); cc8Q}
CountControl c=new CountControl(); 4aW[`
c.run(); $/ $Hi U`.
out.print(CountCache.list.size()+"<br>"); 6J">@+
%>