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: PSyUC#;
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CountBean.java o1-_BlZ
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/*
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* CountData.java SDs#w
* E@AV?@<sc
* Created on 2007年1月1日, 下午4:44 J=HN~B1
* j[dgY1yE:
* To change this template, choose Tools | Options and locate the template under )l`VE_(|
* the Source Creation and Management node. Right-click the template and choose 0ZZ Wj%
* Open. You can then make changes to the template in the Source Editor. 2@I0p\a
*/ #u +~ ^M
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package com.tot.count; ?0qP6'nWx
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/** .>LJ(Sx9b
* O]Yz7
* @author \l`{u)V
*/ dQO5
public class CountBean { U~M!T#\s
private String countType; gP |>gy#e
int countId; aP"!}*
/** Creates a new instance of CountData */ \p]B8hLW
public CountBean() {} vF/wV'Kk
public void setCountType(String countTypes){ e0<O6
this.countType=countTypes; $R:Q R?
} uf"(b"N0
public void setCountId(int countIds){ S6fbwZZMG
this.countId=countIds; H5o=nWQ6e
}
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public String getCountType(){ QV4FA&f&
return countType; 4=N(@mS
} 0sB[]E|7[s
public int getCountId(){ QGE0pWL-a
return countId; 8# x7q>?
} \0&F'V
} MIh\z7gW
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CountCache.java #&%>kfeJ)<
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/* cmU>A721
* CountCache.java \)ZCB7|
* }<*KM)%
* Created on 2007年1月1日, 下午5:01 MIb[}w=
* G^eXJusOv
* To change this template, choose Tools | Options and locate the template under *dPbV.HCl
* the Source Creation and Management node. Right-click the template and choose 81w"*G5AM
* Open. You can then make changes to the template in the Source Editor. &:1q3gDm
*/ \xQu*M:!
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package com.tot.count; 6RDy2JAOP
import java.util.*; c]/S<w<
/** H8 xhE~'t
* 0sTR`Xk
* @author E]=>@EX
*/ J ;4aghzY
public class CountCache { 8;#yXlf
public static LinkedList list=new LinkedList(); NFR>[L V
/** Creates a new instance of CountCache */ \N$)Q.M
public CountCache() {} -Zp BYX5e_
public static void add(CountBean cb){ !SIk9~rJ
if(cb!=null){ B&6lG!K'?
list.add(cb); |68k9rq
} i4nFjz
} [AA}P/iW
} VKf&}u/
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CountControl.java "fW
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/* ? Dn}
* CountThread.java l@ (:Q!Sk
* TwI'XMO;A
* Created on 2007年1月1日, 下午4:57
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* g4952u
* To change this template, choose Tools | Options and locate the template under =itQ@``r
* the Source Creation and Management node. Right-click the template and choose 0%4OmLBT
* Open. You can then make changes to the template in the Source Editor. %%zlqd"0
*/ e[0"x.gu
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package com.tot.count; p@[ fZj
import tot.db.DBUtils; ZY@ntV?
import java.sql.*; P(/eVD#v
/** sx}S,aIU
* !&NrbiuN
* @author a6 1!j>Kx
*/ O;|Cu7WU
public class CountControl{ bdG@%K',
private static long lastExecuteTime=0;//上次更新时间 &b7_%,Bx4
private static long executeSep=60000;//定义更新间隔时间,单位毫秒
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/** Creates a new instance of CountThread */ 9%1J..c
public CountControl() {} P,9Pn)M|
public synchronized void executeUpdate(){ m^=El7+
Connection conn=null; N/--6)5~0
PreparedStatement ps=null; 3!vzkBr
try{ ?~!9\dek,
conn = DBUtils.getConnection(); 1X&jlD?
conn.setAutoCommit(false); e =r
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); >[;=c0(
for(int i=0;i<CountCache.list.size();i++){ $*T?}r>
CountBean cb=(CountBean)CountCache.list.getFirst(); VCJOWUEO1
CountCache.list.removeFirst(); }lT;?|n:h
ps.setInt(1, cb.getCountId()); .{} 8mFi1
ps.executeUpdate();⑴ qZ&~&f|>e
//ps.addBatch();⑵ Bv'%$}}-
} j<k6z
//int [] counts = ps.executeBatch();⑶ |"I)1[7
conn.commit(); py+\e"s
}catch(Exception e){ S(?A3 H
e.printStackTrace(); [[zNAq)"
} finally{ a^pbBDi
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try{ Jazg n5
if(ps!=null) { 2#r4dr0
ps.clearParameters(); :tI
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ps.close(); ,v,rY'
ps=null; 0H]{,mVs
} a@d 15CN
}catch(SQLException e){} 9dBxCdpu
DBUtils.closeConnection(conn); ,&qC
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} t(9q6x3|e
} }m~MN4 l
public long getLast(){ x!\q69nd v
return lastExecuteTime; Q2uV/M1?
} 5j6`W?|q
public void run(){ e}S+1G6r)
long now = System.currentTimeMillis(); f'H|K+bO
if ((now - lastExecuteTime) > executeSep) { >]z^.U7=
//System.out.print("lastExecuteTime:"+lastExecuteTime); d7
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//System.out.print(" now:"+now+"\n"); /XEW]/4
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ^|]Dg &N.
lastExecuteTime=now; ~x#TfeU]
executeUpdate(); "=T&SY
} b*M?\ aA
else{ n P]!{J]
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); q$mc{F($D
} ]z/R?SM
} "\KBF
} G3%Ju=
//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 xZlCFu
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类写好了,下面是在JSP中如下调用。 {svo!pN:
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<% /:'>-253
CountBean cb=new CountBean(); n2hV}t9O
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); G0Qw&
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CountCache.add(cb); Vm>E F~ r
out.print(CountCache.list.size()+"<br>"); >MYDwH
CountControl c=new CountControl(); 9;?u%
c.run(); |=m.eU
out.print(CountCache.list.size()+"<br>"); 9S*"={}%
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