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: #qF1z}L(
E@xrn+L>-
CountBean.java &fWC-|
i^iu#WC
/* 4k3pm&
* CountData.java $oM>?h_=
* <)~-]
* Created on 2007年1月1日, 下午4:44 U9^1A*
* @R%qP>_
* To change this template, choose Tools | Options and locate the template under IQtQf_"e1
* the Source Creation and Management node. Right-click the template and choose {r;_nMfH|[
* Open. You can then make changes to the template in the Source Editor. p4k}B. f
*/ X=abaKl
^,^MW
package com.tot.count; uM_ww6
TIl 'Z7
/** 4@Db $PHs
* ;L -)$Dy4
* @author WwZ3hd
*/ s$fX
;
public class CountBean { {5{VGAD&]>
private String countType; na~ FT[3C
int countId; p U !:
/** Creates a new instance of CountData */ y9R%%i
public CountBean() {} hLuv
public void setCountType(String countTypes){ v{ohrpb0v
this.countType=countTypes; +a|Q)Ob
} w:deQ:k
public void setCountId(int countIds){ ^,ISz-4
this.countId=countIds; v&/H6r#E.
} :7"Q
public String getCountType(){ ;zo|. YD
return countType; cAwqIihZ
} nh@JGy*L
public int getCountId(){ u=W[ S)w
return countId; Dqc
GzTz
} D]*|Zmr+}
} 5VOw}{Pt
^t7u4w!
CountCache.java ]>Z9K@
||wi4TP
/* BLaNS4e
* CountCache.java ovM;6o
* /J_],KdU
* Created on 2007年1月1日, 下午5:01 (.@pe Hu)#
* =M*pym]QSY
* To change this template, choose Tools | Options and locate the template under -2[4 @
* the Source Creation and Management node. Right-click the template and choose BgT ^
* Open. You can then make changes to the template in the Source Editor. et)n`NlcK
*/ TB.>?*<n]
*'A*!=5(
package com.tot.count; 'SlZ-SdR
import java.util.*; 1 /{~t[*.
/** h6O'"
* !a:e=b7g
* @author 0KgP'oWvY
*/ V?G%-+^
public class CountCache { T!y 9v5
public static LinkedList list=new LinkedList(); d^6-P
R_
/** Creates a new instance of CountCache */
H,GjPIG
public CountCache() {} 9d/-+j'
public static void add(CountBean cb){ \a|~#N3?
if(cb!=null){ lGR0-Gh2
list.add(cb); EZI#CLT[
} $<2d|;7r
} KU(BY}/ ^
} 2 G*uv+=
k]r4b`x`
CountControl.java C^4,L
\E
cf,6";8
/* `4xQ#K.-
* CountThread.java e<1Ewml(]
* ?G',Qtz<K
* Created on 2007年1月1日, 下午4:57 GeY!f/yQ<
* P%l?C?L
* To change this template, choose Tools | Options and locate the template under ~>9G\/u j
* the Source Creation and Management node. Right-click the template and choose &a=rJvnIO&
* Open. You can then make changes to the template in the Source Editor. wS9V@
*/ rYdNn0mhk
fu~iF
package com.tot.count; :fL7"\
pf~
import tot.db.DBUtils; K.wRz/M&g
import java.sql.*; 1irSI,j%z
/** >5kz#|@P
* 57;0,k5Gy
* @author 5,^DT15a4P
*/ hLZfArq}
public class CountControl{ A_U=`M=-
private static long lastExecuteTime=0;//上次更新时间 XtZd%
#2},
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 {p/Yz#
/** Creates a new instance of CountThread */ +kYp!00
public CountControl() {} D-C]0Jf3
public synchronized void executeUpdate(){ B1~`*~@
Connection conn=null; )b]wpEFl
PreparedStatement ps=null; =,N"% }
try{ g.`Ntsi$wI
conn = DBUtils.getConnection(); sBI/`dGZV
conn.setAutoCommit(false); qQDe'f~
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); y_n4Y[4g
for(int i=0;i<CountCache.list.size();i++){ svEe@Kt`
CountBean cb=(CountBean)CountCache.list.getFirst(); dz/@]a
CountCache.list.removeFirst(); E+XS7':I
ps.setInt(1, cb.getCountId()); LB]3-FsU+
ps.executeUpdate();⑴ N.z2eo
//ps.addBatch();⑵ l"dXL"h
} mCg^Y)Q
//int [] counts = ps.executeBatch();⑶ ,@;|+C
conn.commit(); aLm~.@Q
}catch(Exception e){ OwNM`xSa|\
e.printStackTrace(); ySiZ@i4
} finally{ YfT
D
try{ Z>y6[o
if(ps!=null) { b~tu;:
ps.clearParameters(); qfCZ
[D
ps.close(); '9.@r\g
ps=null; NV/paoyx:*
} H6K8.
}catch(SQLException e){} mUP!jTF
DBUtils.closeConnection(conn); ju[y-am$/
} 'JdK0w#
} rWNe&gFM
public long getLast(){ "y7\F9
return lastExecuteTime; %`5K8eB
} R|)l^~x
public void run(){ e&i`/m5
long now = System.currentTimeMillis(); ! })Y9oZc8
if ((now - lastExecuteTime) > executeSep) { &P}t<;
//System.out.print("lastExecuteTime:"+lastExecuteTime); |+HJ>xA4I
//System.out.print(" now:"+now+"\n"); Gq[5H(0/c
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); !'#
D~
lastExecuteTime=now; _qf~
hhi
executeUpdate(); `0U\|I#
} nTGf
else{ F?a
63,r
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); "pK<d~Wu
} 0!%G#~th
} %?+Lkj&
} 0%&}w UjV
//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 )XSHKPTQ1
(c}!gjm
类写好了,下面是在JSP中如下调用。 yLCMu | +
X0j> g^b8
<% 2eRk_j]
CountBean cb=new CountBean(); ;?iu@h
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); i qxMTH#!
CountCache.add(cb); OYWHiXE6]
out.print(CountCache.list.size()+"<br>"); _fn7-&6
CountControl c=new CountControl();
&gT@oS{
c.run(); {Z <`@\K3
out.print(CountCache.list.size()+"<br>"); |LLpG37_
%>