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: g<jK^\eW
]tV{#iIJ*
CountBean.java leqSS}KU+
CMf~Yv
/* "+"dALX{3K
* CountData.java SxQDqoA~
* ;@\JscNJ|
* Created on 2007年1月1日, 下午4:44 x~,?Zj)n?C
* *m Tc4&*
* To change this template, choose Tools | Options and locate the template under R}mWHB_h"
* the Source Creation and Management node. Right-click the template and choose .TU15AAc
* Open. You can then make changes to the template in the Source Editor. @?NLME
*/ NNV.x7
#z5?Y2t7~^
package com.tot.count; $f-pLF+x
e/~<\
/** wA+4:CF@
* VFp)`+8
* @author ^*>no=A
*/ [9Hm][|Ph
public class CountBean { fH{$LjH(
private String countType; xo3)dsX
int countId; VH*(>^OfF
/** Creates a new instance of CountData */ 5 `mVe0uI
public CountBean() {} i;
uM!d}
public void setCountType(String countTypes){ 6m<9^NT
this.countType=countTypes; zT 40,rk
} \}(-9dr
public void setCountId(int countIds){ JugQ +0
this.countId=countIds; F#9KMu<<cI
} 4p g(QeR
public String getCountType(){ s0'U[]
return countType; wY)GX
} jh!IOtf
public int getCountId(){ -2XIF}.Hu
return countId; ,$*klod
} o{,(`o.1O
} 438>)=
_e^V\O>
CountCache.java O$ oN1
;L{y3CWT
/* ?AH<y/i<Y
* CountCache.java e
q.aN3KB"
* $O>MV
* Created on 2007年1月1日, 下午5:01 N^>g=Ub
* 3Sb%]f5(
* To change this template, choose Tools | Options and locate the template under wn.0U
* the Source Creation and Management node. Right-click the template and choose F=lj$?4{
* Open. You can then make changes to the template in the Source Editor. 5Ww\h
*/ ^E8Hv
D7oV&vXg
package com.tot.count; B9 {DO
import java.util.*; $a]dxRkz
/** /FXfu
* &Vm[5XW
* @author VdrF=V&] O
*/ =z dti'2{4
public class CountCache { Z ISd0hV
public static LinkedList list=new LinkedList(); ]5L3[A4Vu
/** Creates a new instance of CountCache */ 'S
;vv]}Gs
public CountCache() {} }gt~{9?c
public static void add(CountBean cb){ ,4UJ|D=J
if(cb!=null){ 3`I_
list.add(cb); `hhG^O_
} z[Qv}pv
} Mqy`j9FbL
} g==^ioS}*
1A
*8Jnw
CountControl.java [!$>:_Vq/
1Sr}2@>
/* ]].21
* CountThread.java suSIz 7:
* Ved:w^
,
* Created on 2007年1月1日, 下午4:57 @
vudeaup
* G)`MoVH1
* To change this template, choose Tools | Options and locate the template under >skS`/6
* the Source Creation and Management node. Right-click the template and choose b
/ySt<
* Open. You can then make changes to the template in the Source Editor. h)8_sC
*/ ^6n]@4P
4]R3*F
package com.tot.count; glUP
import tot.db.DBUtils; bvKi0-
import java.sql.*; YWdvL3Bgk,
/** W_EN4p~J
* )$i3j
1[;
* @author _!D$Aj
*/ Ky|0IKE8Z
public class CountControl{ 2:yv:7t/
private static long lastExecuteTime=0;//上次更新时间 P&VI2k
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 AJ}Q,E
/** Creates a new instance of CountThread */ ~>|U %3}]
public CountControl() {} gsH_pG-jU
public synchronized void executeUpdate(){ CaMG$X&O
Connection conn=null; \k8_ZJw
PreparedStatement ps=null; }#M|3h;q9+
try{ dWSH\wm+
conn = DBUtils.getConnection(); .BvV[`P
conn.setAutoCommit(false); IU}`5+:m
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 6P8X)3CE<T
for(int i=0;i<CountCache.list.size();i++){ o\#e7 Hqbh
CountBean cb=(CountBean)CountCache.list.getFirst(); y.2 SHn0
CountCache.list.removeFirst(); N3)EG6vE*
ps.setInt(1, cb.getCountId()); "M]]H^r5
ps.executeUpdate();⑴ `pr,lL
//ps.addBatch();⑵ Z$@Nzza-
} I`l<}M
//int [] counts = ps.executeBatch();⑶ hGLBFe#3
conn.commit(); .#}R$}e+
}catch(Exception e){ )1ciO+_
e.printStackTrace(); 7y&`H
} finally{ %,BJkNV
try{ xOH@V4z:
if(ps!=null) { ^EZoP:x(oE
ps.clearParameters(); G.8ZISN/
ps.close(); W:G*t4i
ps=null; LvaF4Y2v
} +X%yF{^m(
}catch(SQLException e){} X-)6.[9f
DBUtils.closeConnection(conn); +$C5V,H~
} &M0v/!%L
} ]MyWB<9M
public long getLast(){ 2Qy&V/E ?
return lastExecuteTime;
BN0))p
} |{(ynZ]R
public void run(){ &H6Fkza;4
long now = System.currentTimeMillis(); ~?FKww|_*J
if ((now - lastExecuteTime) > executeSep) { L`BLkDm
//System.out.print("lastExecuteTime:"+lastExecuteTime); 6IA~bkc}
//System.out.print(" now:"+now+"\n"); O B:G5B`
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 0FBifK
lastExecuteTime=now; nBd;d}LD
executeUpdate(); tQ"PCm
} Q6E80>
else{ xfilxd
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); \BA_PyS?W+
} 1x]G/I*
} {.AFg/Z
} 6aL`^^
//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 dJk.J9Z
hk(^?Fp
类写好了,下面是在JSP中如下调用。 HDYoM
PeOgXg)L`z
<% vhKD_}}aP
CountBean cb=new CountBean(); 2B|3`trY4x
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); IlY,V
CountCache.add(cb); TX;|g1K
out.print(CountCache.list.size()+"<br>"); h4U .wk
CountControl c=new CountControl(); hM-qC|!
c.run(); v?}/WKe+0
out.print(CountCache.list.size()+"<br>"); MEE]6nU
%>