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: >v f-,B
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CountBean.java *j=58d`n
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/* !tb!%8{~
* CountData.java @|s$:;(=
* ryqu2>(
* Created on 2007年1月1日, 下午4:44 %gWQ}QF
* ~NLthZ(O
* To change this template, choose Tools | Options and locate the template under \.>7w 1p
* the Source Creation and Management node. Right-click the template and choose 0/1=2E^,
* Open. You can then make changes to the template in the Source Editor. RJKi98xwJ
*/ mg" _3].j
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package com.tot.count; OUFy=5(%:
`P <#kt
/** %Y"pVBc
* j<`3xd'
* @author CD5% iFy
*/ !b&+2y2i[W
public class CountBean { apt$e$g
private String countType; 1OqVV?oz
int countId; j\zlp
/** Creates a new instance of CountData */ |Y?<58[!)
public CountBean() {} qz2`%8}F)
public void setCountType(String countTypes){ HXC\``E
this.countType=countTypes; %yd(=%)fMB
}
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public void setCountId(int countIds){ ;?q}98-2
this.countId=countIds; x+ER 3wDD@
} E" >`
public String getCountType(){ o7WAH@g
return countType; 0-;>O|U3
} DuT6Od/f
public int getCountId(){ f=VlO d
return countId; oI'& &Bt
} sI h5cT
} !m%'aQHH(
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CountCache.java q'4P/2)va
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/* &[
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* CountCache.java &328pOT4
* Q1ayd$W@<
* Created on 2007年1月1日, 下午5:01 !uO@4]:Y
* sINf/mv+
* To change this template, choose Tools | Options and locate the template under ,>za|y<n
* the Source Creation and Management node. Right-click the template and choose yla-X|>
* Open. You can then make changes to the template in the Source Editor. O[{/P:a
*/ ]9)iBvQlj
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package com.tot.count; mBb3Ta
import java.util.*; *po
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/** e|5@7~Vi
* B~|]gd
* @author nB5\ocJ
*/ q @O
public class CountCache { o0>|
public static LinkedList list=new LinkedList(); =wW M\f`=
/** Creates a new instance of CountCache */ Di27=_J
public CountCache() {} Q672iR\#)
public static void add(CountBean cb){ j@^zK!mO
if(cb!=null){ i+_=7(e
list.add(cb); /#SfgcDt
} *OdmKVw6G
} "Nb2[R
} :uB?h1|
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CountControl.java 0l& '`
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/* H&%oHyK
* CountThread.java F$jy~W_
* esE!i0%
* Created on 2007年1月1日, 下午4:57 &-p~UZy
* d>W#c8X>
* To change this template, choose Tools | Options and locate the template under hkm}oYW+
* the Source Creation and Management node. Right-click the template and choose =$^90Q,Z;
* Open. You can then make changes to the template in the Source Editor. _b>{:H&\
*/ 8~t8^eBg
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package com.tot.count; i+in?!@G:
import tot.db.DBUtils; X%znNx
import java.sql.*; 6}Tftw$0z
/** Eu~1t& 4
* bZ:+q1
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* @author QV HI}3~
*/ E>i<2
public class CountControl{ ,}@4@ >?K
private static long lastExecuteTime=0;//上次更新时间 !OQ5AF$
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 "S6";G^I
/** Creates a new instance of CountThread */ n1JV)4Mv
public CountControl() {} 00f'G2n
public synchronized void executeUpdate(){ ZzTkEz >
Connection conn=null; @#hvQ6u
PreparedStatement ps=null; 1 I.P7_/
try{ 8#tuB8>
conn = DBUtils.getConnection(); jP_s(PQ
conn.setAutoCommit(false); 3.hFYA w
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 9QB,%K_:4
for(int i=0;i<CountCache.list.size();i++){ F=w:!tqA
CountBean cb=(CountBean)CountCache.list.getFirst(); 42tZBz&
CountCache.list.removeFirst(); ^'M^0'_"v
ps.setInt(1, cb.getCountId()); O CIoY?a
ps.executeUpdate();⑴ fe`_0lxj
//ps.addBatch();⑵ 7RBEEE`)
} %+,*$wk#*
//int [] counts = ps.executeBatch();⑶ <-b9
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conn.commit(); $ (xdF
}catch(Exception e){ H
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e.printStackTrace(); P(2OTfGGx
} finally{ R"JXWw
try{ |4
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if(ps!=null) { trrK6(p
ps.clearParameters(); U9^1A*
ps.close(); \xl$z*zI
ps=null; D_JGbNigA
} LL
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}catch(SQLException e){} Sew*0S(
DBUtils.closeConnection(conn); irq{ 21
} "+7E9m6I
} ;L -)$Dy4
public long getLast(){ 5Rs#{9YE
return lastExecuteTime; X<C fy
} {D..(f1*u
public void run(){ y9/nkF1p
long now = System.currentTimeMillis(); .N.RpRz{f
if ((now - lastExecuteTime) > executeSep) { ;n*|AL7(
//System.out.print("lastExecuteTime:"+lastExecuteTime); (7b9irL&cn
//System.out.print(" now:"+now+"\n"); \<`oW>
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); I;E?;i
lastExecuteTime=now; z_R^C%0k
executeUpdate(); oOvQAW8`
} 0x5Ax=ut
else{ F@q9UlfB-
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); }i^|.VZZ
} Kx)PK
} T*0;3&sA
} !
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//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 f R@Cg
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类写好了,下面是在JSP中如下调用。 >2pxl(i
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<% =$gBWS
CountBean cb=new CountBean(); - QY<o|
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); :n{{\SSIgX
CountCache.add(cb); 3~3tjhw;]9
out.print(CountCache.list.size()+"<br>"); 9oGcbD4*
CountControl c=new CountControl(); |,oLZCNa
c.run(); =:w,wI.
out.print(CountCache.list.size()+"<br>"); V~/-e- 9u
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