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: 0W1=9+c|X
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CountBean.java -{A!zTw1w
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/* MxXu&.|_
* CountData.java Zg@NMT
* i1#\S0jN
* Created on 2007年1月1日, 下午4:44 fy`e)?46
* =os%22*
* To change this template, choose Tools | Options and locate the template under 4Fr\=TX
* the Source Creation and Management node. Right-click the template and choose p ^U:O&U(
* Open. You can then make changes to the template in the Source Editor. >|[74#}7
*/ u}7#3JfLn
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package com.tot.count;
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/** LI&+5`
* h>6'M
* @author Xh,{/5m
*/ hK+Iow-
public class CountBean { <[H1S@{W
private String countType; 0.~Pzg
int countId; I]]3=?Y
/** Creates a new instance of CountData */ \I@=EF- &
public CountBean() {} z~/z>_y$nv
public void setCountType(String countTypes){ ov=[g l
this.countType=countTypes; (= H%VXQH
} E0<9NFQr7
public void setCountId(int countIds){ T
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this.countId=countIds; X;7gh>Q'4
} `5[d9z/ 6
public String getCountType(){ k;w1y(
return countType; ?=B$-)/
} 9=j"kXFf
public int getCountId(){ Zu\(XN?62
return countId; %&+j(?9
} lCDu,r;\
} vs/.'yD/C
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CountCache.java FY [WdZDZ
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/* [a;U'v*
* CountCache.java C:/O]slH
* CBAMAr
* Created on 2007年1月1日, 下午5:01 }&)X4=
*
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* To change this template, choose Tools | Options and locate the template under J#7\R':}zl
* the Source Creation and Management node. Right-click the template and choose $9DV}
* Open. You can then make changes to the template in the Source Editor. 84UH&
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*/ c
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package com.tot.count; sr+*
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import java.util.*; V,<3uQD9a
/** MzRwsf
* {
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* @author tCAh?nR
*/ hA.?19<Z
public class CountCache { $<.\,wW*'w
public static LinkedList list=new LinkedList(); 5o 4\Jwt
/** Creates a new instance of CountCache */ n=#AH;42
public CountCache() {} A*jU&3#
public static void add(CountBean cb){ -xS{{"-
if(cb!=null){ o(GXv3L
list.add(cb); ;uj&j1
} duCxYhh|
} pj:s+7"t
} @: u>
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CountControl.java sdF;H[
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/* SJb+:L>
* CountThread.java h.PVR Awk
* D#}t)$"
* Created on 2007年1月1日, 下午4:57 #9-qF9M
* .)L%ANf
* To change this template, choose Tools | Options and locate the template under LpwjP4vWJ
* the Source Creation and Management node. Right-click the template and choose '4-J0S<<_
* Open. You can then make changes to the template in the Source Editor. #-5.G>8
*/ Bx9R!u5D
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package com.tot.count; VfWU-lJ
import tot.db.DBUtils; 9u6GeK~G
import java.sql.*; 8S*3W3HY
/** zh8\
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* je_:hDr
* @author .g/PWEr\I
*/ r<< ]41
public class CountControl{ P1cI]rriW
private static long lastExecuteTime=0;//上次更新时间 z~8`xn,
private static long executeSep=60000;//定义更新间隔时间,单位毫秒
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/** Creates a new instance of CountThread */ "[A]tklP
public CountControl() {} (*qMs)~]B
public synchronized void executeUpdate(){ XT2:XWI8
Connection conn=null; i2bkgyzB.
PreparedStatement ps=null; ckDWY<@v
try{ |E]`rfr
conn = DBUtils.getConnection(); PB[Y^q
conn.setAutoCommit(false); N{b;kiZq
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); olA 1,8
for(int i=0;i<CountCache.list.size();i++){ 3[_zz;Y*d
CountBean cb=(CountBean)CountCache.list.getFirst(); 9NXL8QmC8
CountCache.list.removeFirst(); E4}MU}C#[
ps.setInt(1, cb.getCountId()); V
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ps.executeUpdate();⑴ M~h^~:Lk
//ps.addBatch();⑵ AFM Ip^F
} 76IjM4&a
//int [] counts = ps.executeBatch();⑶ qoZUX3{
conn.commit(); r<)>k.]
!
}catch(Exception e){ Z'Uc}M'U
e.printStackTrace(); fx74h{3u
} finally{ BYuoeN!
try{ xZ=6
if(ps!=null) { :o37 V!
ps.clearParameters(); E]MyP=g$
ps.close(); %f-Uwq&}Y"
ps=null; z5tOsU
} "aT"o
}catch(SQLException e){} U"T>L
DBUtils.closeConnection(conn); A_pcv7=@
} w]ihGh
} =w,cdU*
public long getLast(){ x<=<Lx0B;
return lastExecuteTime; [TaYNc!\
} bnZ`Wc*5b
public void run(){ w~a_FGYX
long now = System.currentTimeMillis(); &sA@!
if ((now - lastExecuteTime) > executeSep) { IKs2.sj"o
//System.out.print("lastExecuteTime:"+lastExecuteTime); e0e3b]
//System.out.print(" now:"+now+"\n"); be+]kp
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); &al\8
lastExecuteTime=now; :c/](M
executeUpdate(); nW"ml$
} _GtG8ebr
else{ <#ZDA/G(
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); (X|`|Y
} G5Z_[Q~z
} k2Dq~zn
} 8]2j*e0xV
//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 U#gv ~)\k
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类写好了,下面是在JSP中如下调用。 n[c/L8j
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<% F#>^S9Gml
CountBean cb=new CountBean(); 6v(;dolBIw
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); O{&wqV5m"
CountCache.add(cb); 7a#zr_r
out.print(CountCache.list.size()+"<br>"); B,NHy
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CountControl c=new CountControl(); !fT3mI6u\
c.run(); _usi~m
out.print(CountCache.list.size()+"<br>"); <&87aDYz
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