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: (6i.>%|_
*YP;HL
CountBean.java H) q_9<;
uL=FK
/* k}e~xbh-y
* CountData.java #6 M3BF
* Tuy5h5
* Created on 2007年1月1日, 下午4:44 t0)XdIl8
* 6FEIQ#`{
* To change this template, choose Tools | Options and locate the template under xDn#=%~+x
* the Source Creation and Management node. Right-click the template and choose uiaZ@
* Open. You can then make changes to the template in the Source Editor. P:m6:F@hO
*/ N[sJ5oF
dU|&- .rG
package com.tot.count; w!52DBOe+
<!PbD
/** p ^ )iC&*0
* 4u7^v1/
* @author h:<?)g~U
*/ +.66Ky`|[
public class CountBean { WdT iao,r
private String countType; Z (C0+A\
int countId; = Tq\Ag:
/** Creates a new instance of CountData */ GNoUn7Y
public CountBean() {} uX+ YH
public void setCountType(String countTypes){ :E2 ww`
this.countType=countTypes; 2@|,VN V6~
} h&:XO9dY
public void setCountId(int countIds){ ?GeMD
/]
this.countId=countIds; {w<"jw&2
} vm8ER,IW)
public String getCountType(){ C]ef
`5NR]
return countType; ??,/85lM
} ed$w5dv
public int getCountId(){ Ev0=m;@_
return countId; r!/<%\S
} "_n})s
f
} f_| =EQ
M[7$F&&n
CountCache.java rch Kr w
i?'|}tK
/* >4nQ&b.u
* CountCache.java B;J8^esypD
* b}Xh|0`b+
* Created on 2007年1月1日, 下午5:01 }KR"0G[f
* |_%q@EID
* To change this template, choose Tools | Options and locate the template under l|K$6>80
* the Source Creation and Management node. Right-click the template and choose HD>UTX`&mc
* Open. You can then make changes to the template in the Source Editor. >yqFO
*/ C\}M_MD
f^G-ba
package com.tot.count; \ 9#X]H
import java.util.*; gh.+}8="
/** .:B;%*
* NPLJ*uHH
* @author TECp!`)j"
*/ PgYIQpV
public class CountCache { &|fWtl;43
public static LinkedList list=new LinkedList(); c2fw;)j&X
/** Creates a new instance of CountCache */ oe[f2?-
public CountCache() {} #F'8vf'r
public static void add(CountBean cb){ Wn Ng3'6
if(cb!=null){ q)OCY}QA
list.add(cb); -BEd7@?A
} yhd]s0(!
} W@Rb"5Gy+
} >lF@M-
'm.+ S8
CountControl.java -b=Aj8h
3|4<SMm
/* ?7A>|p?"
* CountThread.java H}gp`YW:4
* <AU0ir
* Created on 2007年1月1日, 下午4:57 b8|<O:]Hp
* - 9a4ej5
* To change this template, choose Tools | Options and locate the template under
fxc?+<P
* the Source Creation and Management node. Right-click the template and choose "0J;H#Y"#
* Open. You can then make changes to the template in the Source Editor. o~26<Lk
*/ ^n*:zmD
c uHF^l
package com.tot.count; $aHHXd}@t2
import tot.db.DBUtils; RhkTN'vO
import java.sql.*; 5.QY{+k
/** I8{
mk h
* "pc
t#
* @author o&>aYlXd
*/ 06[HE7
public class CountControl{ UHBMl>~z
private static long lastExecuteTime=0;//上次更新时间 #q6#nfi"
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 >O~
/** Creates a new instance of CountThread */ q I*7ToBJ
public CountControl() {} hp}JKj@
public synchronized void executeUpdate(){ ku
GaOO
Connection conn=null; =4gPoS
PreparedStatement ps=null; |2Uw8M7.E
try{ Uz%2{HB@{
conn = DBUtils.getConnection(); _=HNcpDA;0
conn.setAutoCommit(false); $ J!PSF8PL
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); X~Hm.qIR
for(int i=0;i<CountCache.list.size();i++){ >~ L0M
CountBean cb=(CountBean)CountCache.list.getFirst(); ;Swy5z0=ro
CountCache.list.removeFirst(); g1~wg$`S8S
ps.setInt(1, cb.getCountId()); L+8O
4K{
ps.executeUpdate();⑴ nxe9^h7m
//ps.addBatch();⑵
9s?gI4XN
} ym'!f|9AA
//int [] counts = ps.executeBatch();⑶ Wjr^: d
conn.commit(); Av!xI
}catch(Exception e){ r(JP&
@
e.printStackTrace(); '~zi~Q7M
} finally{ q2*1Gn9!j
try{ ywA7hm
if(ps!=null) { vPAL,
ps.clearParameters(); hP$5>G(3
ps.close();
I!T=$Um
ps=null; b"w@am>&
} e'.CIspN
}catch(SQLException e){} C]Q}HI#G
DBUtils.closeConnection(conn); ubMN
} f(
<O~D
} W#\{[o
public long getLast(){
pRA%07?W
return lastExecuteTime; s01=C3
} V,]Fh5f
public void run(){ ?Cv([ ^Y.u
long now = System.currentTimeMillis(); FIx|4[&>S
if ((now - lastExecuteTime) > executeSep) { 0rxGb} b*
//System.out.print("lastExecuteTime:"+lastExecuteTime); WAJKP"
//System.out.print(" now:"+now+"\n"); Q;GcV&f;f
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); u-*z#e_L0
lastExecuteTime=now; &ju.5v|
executeUpdate(); dnkHx
} Vze vOS
else{ S_38U
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ]d.e(yCuE
} X XxH<E$p
} g @NwW&
} w!-MMT4y
//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 l[[^]__
X6xs@tgQ
类写好了,下面是在JSP中如下调用。 m@2=vq1f
|?TX^)
<% t+D= @"BZP
CountBean cb=new CountBean(); (S2E'L L{
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); h=^UMat-
CountCache.add(cb); |-z"6F r-
out.print(CountCache.list.size()+"<br>"); ,\N4tG1\
CountControl c=new CountControl(); MHJRBn{}
c.run(); O+]'*~a
out.print(CountCache.list.size()+"<br>"); 1C0'
Gf)3
%>