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: 7=aF-;X3jj
Vf`1'GY
CountBean.java "U4Sn'&h@
4b,N"w{v
/* {%)bxk6
* CountData.java Z)~.OqRw]
* &C`t(e
* Created on 2007年1月1日, 下午4:44 AQDT6E:
*
R%"wf
* To change this template, choose Tools | Options and locate the template under r**u=q%p
* the Source Creation and Management node. Right-click the template and choose 4S`2")V
* Open. You can then make changes to the template in the Source Editor. vxzh|uF
*/ pGc_Klq
%J5zfNe)&
package com.tot.count; >RG
}u
?;ZTJ
/** z
v*hA/
* 2$V]XSe
* @author jn&[=Y-
*/ '+hiCX-_
public class CountBean { t5\~Z}G8
private String countType; <w}YD @(f
int countId; MRMswNQ
/** Creates a new instance of CountData */ E=_M=5]
public CountBean() {} GKTrf\"c
public void setCountType(String countTypes){ b*+Od8r
this.countType=countTypes; r n"'tvhm
} F3HpDfy
public void setCountId(int countIds){ /59jkcA+
this.countId=countIds; Gg]>S#^3
} n{s
`XyH
public String getCountType(){ .J6Oiv.E
return countType; qL/4mM0
} ^i&sQQ({
public int getCountId(){ K?+iu|$&
return countId; "94e-Nx
} UA>UW!I
} Mj&q"G
(j@3=-%6 G
CountCache.java 0
XxU1w8\V
s"7wG!yf
/* bS=aFl#
* CountCache.java
] lE6:^V
* 3xj
?}o
* Created on 2007年1月1日, 下午5:01 JL5
)
* Uo>pV9xRG
* To change this template, choose Tools | Options and locate the template under 80TSE*
* the Source Creation and Management node. Right-click the template and choose v9QR,b`n
* Open. You can then make changes to the template in the Source Editor. 9lbe[w@
*/ /GCI`hx>"
ebxpKtEC
package com.tot.count; (RW02%`jjy
import java.util.*; >k)}R|tJ
/** &ejJf{id
* L #c*)
* @author 1S/KT4
*/ h;?=:(
public class CountCache { rtd&WkU
rD
public static LinkedList list=new LinkedList(); ZCsL%(
/** Creates a new instance of CountCache */ FH:^<^M
public CountCache() {} 8 h
public static void add(CountBean cb){ L 1iA
^x
if(cb!=null){ R >f$*T
list.add(cb); $9k7A 8K
} 1Tz5tU9kR
} P(D0ru
} *{5p/}p
i P gewjx
CountControl.java JR>#PJ,N-
\X1?,gV_
/* 6g06s @kz
* CountThread.java 7VQ|3`!<
* \ <b-I
* Created on 2007年1月1日, 下午4:57 }i0(^"SoXZ
* pxy=edd
* To change this template, choose Tools | Options and locate the template under JG\T2/b
* the Source Creation and Management node. Right-click the template and choose zg L0v5vk
* Open. You can then make changes to the template in the Source Editor. {=};<;_F
*/ Qk 2^p^ T6
/qM:;:N%j
package com.tot.count; N.R,[K
import tot.db.DBUtils; ?"-%>y@w
import java.sql.*; mux_S2x9m\
/** pm`BMy<5PU
* *Y'nDv6_P
* @author YL*yiZ9
*/ !ZlBM{C
public class CountControl{ Jm0o[4
private static long lastExecuteTime=0;//上次更新时间 4JV/Ci5
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 r$7fw}'I
/** Creates a new instance of CountThread */ HQqnJ;ns<
public CountControl() {} X <QSi
public synchronized void executeUpdate(){ WxO2
Connection conn=null; QlT{8uw)
PreparedStatement ps=null; |-t>_+. J'
try{ H?A&P4nZ
conn = DBUtils.getConnection(); hr9rI
conn.setAutoCommit(false); 5~)m6]-6
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); H809gm3(Z
for(int i=0;i<CountCache.list.size();i++){ 8NU <lV`
CountBean cb=(CountBean)CountCache.list.getFirst(); I2"F2(>8K
CountCache.list.removeFirst(); ;>%@
ps.setInt(1, cb.getCountId()); )\oLUuL`;
ps.executeUpdate();⑴ g+'=#NS}
//ps.addBatch();⑵ ^U1@
hq*u
} u~[=5r
//int [] counts = ps.executeBatch();⑶ 3,;;C(
conn.commit(); CRXIVver
}catch(Exception e){ a;@G
e.printStackTrace(); W\f u0^
} finally{ N1dv}!/*.+
try{ OAx5 LTd
if(ps!=null) { `?@7T-v
ps.clearParameters(); b/^i
ps.close(); oZVq}}R
ps=null; _OR@S%$
} YKCd:^u
}catch(SQLException e){} :g@H=W
DBUtils.closeConnection(conn); ,gY bi-E
} NHI(}Ea|]
} jNjm}8`t
public long getLast(){ y$-;6zk\]
return lastExecuteTime; 0_\@!#-sml
} /4K ^-
public void run(){ {k:W?`
long now = System.currentTimeMillis(); 6ooCg>9/Z
if ((now - lastExecuteTime) > executeSep) { z#DgoA
//System.out.print("lastExecuteTime:"+lastExecuteTime); 04npY+1
8%
//System.out.print(" now:"+now+"\n"); \Z~|ry0v{d
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); _6O\*|'6
lastExecuteTime=now; }\
^J:@
executeUpdate(); W.67};',
} ^)wTCkH&y
else{ O:G5n 5J
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); k+nfW]UNF
} quky m3F
} jEaU;
} TDqH"q0
//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 Ng=_#<
-(ev68'}W
类写好了,下面是在JSP中如下调用。 nogdOGo
cZVVJUF
<% coG_bX?e
CountBean cb=new CountBean(); ;^yR,32F
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); g+:Go9k!F
CountCache.add(cb); <r`^iR)%
out.print(CountCache.list.size()+"<br>"); m@A?'gD
CountControl c=new CountControl(); 3]z%C'
c.run(); u[Ij4h.
out.print(CountCache.list.size()+"<br>"); %]U'
%>