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: quu*xJ;Ci
%:C ]7gQ
CountBean.java r64u31.)
!
T9]/H?
/* Yx d X#3
* CountData.java C*70;:b
* dKhA$f~
* Created on 2007年1月1日, 下午4:44 9h,u6e
* 5_o$<\I\
* To change this template, choose Tools | Options and locate the template under ./-JbW
* the Source Creation and Management node. Right-click the template and choose h1"zV6U
* Open. You can then make changes to the template in the Source Editor. J{"kw1Lu
*/ b!>\2DlyJ
Vd9@Dy
package com.tot.count; (&\aA 0-}H
;e8V
+h
/** /\d$/~BFi
* U HO_Z
* @author Y}R}-+bD/
*/ E_ucab-Fi
public class CountBean { |Rzy8j*
private String countType; Q[ieaL6&
int countId; T~8
.9g
/** Creates a new instance of CountData */ g=)J~1&p
public CountBean() {} 72db[
public void setCountType(String countTypes){ n]!fO
6kj
this.countType=countTypes; rp34?/Nz
} &lc8G
public void setCountId(int countIds){ Z+:D)L
this.countId=countIds; Jc*XXu)
} kMxazx1
public String getCountType(){ Y;J *4k]
return countType; _O:WG&a6
} h rN%
public int getCountId(){ :Og:v#r8=
return countId; ?>uew^$d[w
} -#&kYK#Ph
} ,t$,idcT+
bMoAD.}
CountCache.java pb;")Q'
(zo^Nn9VJ
/* =d;Vk
* CountCache.java !cEG}(|h
* y>VcgLIB
* Created on 2007年1月1日, 下午5:01 /i|z.nNO
* ':
F}3At
* To change this template, choose Tools | Options and locate the template under Tp%(I"H'_;
* the Source Creation and Management node. Right-click the template and choose pa
.K-e)Mu
* Open. You can then make changes to the template in the Source Editor. sYbH|}
*/ nY?
}k$4/7ri
package com.tot.count; g<*jlM1r
import java.util.*; S4NL "m
/** rjA@U<o
* e,1u
* @author W=}Okq)x9I
*/ /!FWuRe^
public class CountCache { Xo5$X7m
public static LinkedList list=new LinkedList(); h\[\\m
O
/** Creates a new instance of CountCache */ tV;%J4E'
public CountCache() {} HaNboYW_K
public static void add(CountBean cb){ E;\M1(\u
if(cb!=null){ 8|1^|B(l
list.add(cb); eH>#6R1-
} "AueLl)
} 43:t
\
} V-O(U*]
CX/(o]
CountControl.java j}HFs0<L
<_S@6?
/* |lQ;ALH!
* CountThread.java KJhN J
* XH 4d<?qu
* Created on 2007年1月1日, 下午4:57 B uQ|~V
* h#YD~!aJ
* To change this template, choose Tools | Options and locate the template under 4)-)# `K
* the Source Creation and Management node. Right-click the template and choose yOXO)u1n
* Open. You can then make changes to the template in the Source Editor. Q'NmSX)0
*/ ~Vh =5J~
my\&hCE
package com.tot.count; Iq5pAHm>M6
import tot.db.DBUtils; Xh3;
import java.sql.*; .#6MQJ]OH
/** RNJFSD.
* NC23Z0y
* @author '%iPVHK7
*/ PBqy F
public class CountControl{ +",S2Qmo
private static long lastExecuteTime=0;//上次更新时间 $K}.
+`vVO
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ('k<XOi
/** Creates a new instance of CountThread */ @M;(K<%h
public CountControl() {} ?s%v0cF
public synchronized void executeUpdate(){ 'A{h iY
Connection conn=null; R'K/t|MC
PreparedStatement ps=null; nL`9l1
try{ I`B'1"{
conn = DBUtils.getConnection(); 0~A#>R'
conn.setAutoCommit(false); eb:A1f4L
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); <>&=n+i
for(int i=0;i<CountCache.list.size();i++){ H?rg5TI0
CountBean cb=(CountBean)CountCache.list.getFirst(); L&2u[ml
CountCache.list.removeFirst(); fjz) Gp
ps.setInt(1, cb.getCountId()); 7ETjn)%bs
ps.executeUpdate();⑴ GuQRn
//ps.addBatch();⑵ %uDG75KP{
} JNU/`JN9f
//int [] counts = ps.executeBatch();⑶ I2Ev~!
conn.commit(); TR vZ
}catch(Exception e){ Pe7e?79
e.printStackTrace(); 2!&pEqs
} finally{ }7/e8 O2
try{ UGKaOol.
if(ps!=null) { sa-9$},z4
ps.clearParameters(); }6m?d!m
ps.close(); v"6 \=@
ps=null; 59 2;W-y
} rGwIcx(%
}catch(SQLException e){} >l1r,/\\
DBUtils.closeConnection(conn); x"B'zP
} kT oOIx
} Y*YFB|f?
public long getLast(){ eD#XDK
return lastExecuteTime; [I+9dSM1t
} cnNOZ$)
public void run(){ v"lf-c
long now = System.currentTimeMillis(); gT52G?-
if ((now - lastExecuteTime) > executeSep) { je%M AgW`
//System.out.print("lastExecuteTime:"+lastExecuteTime); P~7.sM
//System.out.print(" now:"+now+"\n"); 7k8n@39?
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); j~av\SCU*
lastExecuteTime=now; VV3}]GjC
executeUpdate(); i.a _C'<$
} 7nE"F!d+0
else{ `u'dh{,gE
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); IM(u<c$
} e<+<lj"
} !c(QSf502
} d,#.E@Po
//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 b5`KB75sbo
FvImX
类写好了,下面是在JSP中如下调用。 W4(?HTWZ
)m#']c:rg
<% fj']?a!m
CountBean cb=new CountBean(); n~r 9!m$<
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); wq0aF"k
CountCache.add(cb); N +Sq}hI
out.print(CountCache.list.size()+"<br>"); s;.=5wcvi?
CountControl c=new CountControl(); R, 0Oq5
c.run(); $Xf (^K
out.print(CountCache.list.size()+"<br>"); G2Qjoe`Uc
%>