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: { 3``T o$
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CountBean.java u\YH,
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/* B$~oZ'4v
* CountData.java '[#a-8-JY_
* ~3}Gu^@
* Created on 2007年1月1日, 下午4:44 g\MHv#v*k
* {FzL@!||
* To change this template, choose Tools | Options and locate the template under Ol ,;BZHc\
* the Source Creation and Management node. Right-click the template and choose rfqw/o
* Open. You can then make changes to the template in the Source Editor. xdWfrm$;ZA
*/ (Wkli:Lq
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package com.tot.count; _^4\z*x
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/** n^|;J*rD
* bc}X.IC
* @author vW4~\]
*/ TR!^wB<F
public class CountBean { 1);$#Dlt
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private String countType; 7q bGA K
int countId; mhnjYK9
/** Creates a new instance of CountData */ PfX{n5yBW8
public CountBean() {} hW*2Le!I
public void setCountType(String countTypes){ DO<eBq\O
this.countType=countTypes; :V2"<]
} `-zdjc d
public void setCountId(int countIds){ *]2LN$
this.countId=countIds; xt]Z{:.
} SQ#6~zxl
public String getCountType(){ YwGc[9=n
return countType; r\]yq-_
} ';`fMcN
public int getCountId(){ Ke-Q>sm2Q
return countId; kN uDoo]z
} z9:@~3k.
} G yZYP\'S+
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CountCache.java }*Qd]\fy
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/* "sLdkd}dj
* CountCache.java ={' "ATX(U
* ~XGO^P"?
* Created on 2007年1月1日, 下午5:01 '^ '4C'J
* 1@IRx{v$
* To change this template, choose Tools | Options and locate the template under uY0V!W
* the Source Creation and Management node. Right-click the template and choose "^-U#f>k
* Open. You can then make changes to the template in the Source Editor. R`=3lY;
*/ &SS"A*xg
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package com.tot.count; 8?] :>
import java.util.*;
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/** ~^/zCPy[w
* J5L P#o(V
* @author ja$>>5<q
*/ L/(e/Jalg
public class CountCache { (^GVy=
public static LinkedList list=new LinkedList(); $;un$ko6%
/** Creates a new instance of CountCache */ 1"46OCu{
public CountCache() {} i}
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public static void add(CountBean cb){ q0WW^jwQ
if(cb!=null){ )gdv!
list.add(cb); ||
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} Ab7hW(/
} /uI/8>p(
} b~06-dk1
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CountControl.java iHjo3_g)n
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/* 7=XQgbY/
* CountThread.java l|`FW
* }yqRz6=YB
* Created on 2007年1月1日, 下午4:57 J#*Uf>5NY
* `7jm
* To change this template, choose Tools | Options and locate the template under Fk D
* the Source Creation and Management node. Right-click the template and choose mOwgk7s[J
* Open. You can then make changes to the template in the Source Editor. :NU-C!eT
*/ s#w+^Mw$
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package com.tot.count; "M6a_rZ2W
import tot.db.DBUtils; FW7+!A&F
import java.sql.*; EZ #UdK_
/** Y0BvN`E
* @RotJl/>
* @author O;[PEV~
*/ La%\-o
public class CountControl{ )DMu`cD
private static long lastExecuteTime=0;//上次更新时间 )ufHk
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 DGY#pnCu
/** Creates a new instance of CountThread */ yb/<
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public CountControl() {} W9 y8dw.
public synchronized void executeUpdate(){ Qpd-uC_Ni
Connection conn=null; yp5*8g5
PreparedStatement ps=null; }7hpx!s,
try{ j5z, l
conn = DBUtils.getConnection(); [e)81yZG>
conn.setAutoCommit(false); :w_F<2d0
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); !boKrSw
for(int i=0;i<CountCache.list.size();i++){ ]Oc
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CountBean cb=(CountBean)CountCache.list.getFirst(); $o\p["DP
CountCache.list.removeFirst(); iM2
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ps.setInt(1, cb.getCountId()); fEs957$
ps.executeUpdate();⑴ MSeO#X
//ps.addBatch();⑵ wI>JOV7
} 4 E3@O
//int [] counts = ps.executeBatch();⑶ ,- ]2s_
conn.commit(); {+c/$4<
}catch(Exception e){ )$q<"t\#P#
e.printStackTrace(); hx4!P( o1
} finally{ ==x3|^0y
try{ X2@mQ&n
if(ps!=null) { \$;\,p p
ps.clearParameters(); P@9>4}r$
ps.close(); 7~\Dzcfk"P
ps=null; NOyLZa'
} QXJD'c
}catch(SQLException e){} ZC"6B(d
DBUtils.closeConnection(conn); ([|5(Omd\
} VK`_Qc#B
} W3UK[_qK
public long getLast(){ CW\o>yh
return lastExecuteTime; /p\Ymq
} yD1*^~ loJ
public void run(){ 2DQ'h}BI
long now = System.currentTimeMillis(); u-UUF
if ((now - lastExecuteTime) > executeSep) { ?^BsR
//System.out.print("lastExecuteTime:"+lastExecuteTime); 1@)]+* F*z
//System.out.print(" now:"+now+"\n"); {DN c7G
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); n!Y.?mU6
lastExecuteTime=now; t{~"vD9Am
executeUpdate(); $O}gl Q
} 1\YX|
else{ Ccz:NpK+
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); qjR;c&
q R
} 8e>;E
} I.x0$ac7
} ~$r^Ur!E\
//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 8YkP57Y%[Z
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类写好了,下面是在JSP中如下调用。 H'gPGOd
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<% gY0*u+LF
CountBean cb=new CountBean(); %c^]Rdl
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); h>mQ; L
CountCache.add(cb); ItM?nyA
out.print(CountCache.list.size()+"<br>"); c09]Cp<
CountControl c=new CountControl(); KXw
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c.run(); um,/^2A
out.print(CountCache.list.size()+"<br>"); w2{k0MW
%>