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: oYHj~t
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CountBean.java w;D+y*2
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/* <
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* CountData.java k2E0/ @f{k
* =Xm@YVf&ZD
* Created on 2007年1月1日, 下午4:44 ai}mOyJs
* hS_6
* To change this template, choose Tools | Options and locate the template under D@C-5rmq
* the Source Creation and Management node. Right-click the template and choose PxF<\pu&
* Open. You can then make changes to the template in the Source Editor. TPVVck-T8
*/ YpQ7)_s?
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package com.tot.count; ;V@WtZv
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/** ~7Y+2FZ
* J5*tJoCYS
* @author ~0?mBy!-O
*/ NIh:DbE
public class CountBean { WegtyO
private String countType; INUG*JC6
int countId; Y_}mYvJW
/** Creates a new instance of CountData */
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public CountBean() {} l;af~ef)'
public void setCountType(String countTypes){ a5 *2h{i
this.countType=countTypes; X7[^s
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} R=.4
public void setCountId(int countIds){ 9F6F~::l}
this.countId=countIds; L}GC<D:
} u?>B)PW
public String getCountType(){ ~+bv6qxg]\
return countType;
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} qNI,
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public int getCountId(){ P-`M
return countId; b:=TB0Fx?n
} qe #P?[
} C(S'#cm
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CountCache.java XIvn_&d;G
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/* fKp#\tCc y
* CountCache.java XEC(P
* sBu=e7
* Created on 2007年1月1日, 下午5:01 F&])P-
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* u583_k%
* To change this template, choose Tools | Options and locate the template under iP@ZM=&wz
* the Source Creation and Management node. Right-click the template and choose h tx;8:
* Open. You can then make changes to the template in the Source Editor. 7~&/_3
*/ [v$0[IuY,
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package com.tot.count; U`,0]"Qk
import java.util.*; 'D6T8B4
/** /D5`
* ;2@BO-3K
* @author H_EB1"C;\
*/ *4U^0e
public class CountCache { z ?[r
public static LinkedList list=new LinkedList(); e?`5>& Up
/** Creates a new instance of CountCache */ '7D,m
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public CountCache() {} uA,>a>xYI
public static void add(CountBean cb){ z ^_*&
if(cb!=null){ 4
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list.add(cb); 5K^69mx
} fLDg~;3
} 0q.Ujm=,z
} ~ zil/P8
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CountControl.java O=v#{ [
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/* E Q4KV
* CountThread.java {88gW\GL
* $={:r/R`i
* Created on 2007年1月1日, 下午4:57 1rKlZsZ#*
* %|^OOU}
* To change this template, choose Tools | Options and locate the template under {o!KhF:[
* the Source Creation and Management node. Right-click the template and choose CM<]ZG7
* Open. You can then make changes to the template in the Source Editor. gzjR6uz
*/ `W dD8E
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package com.tot.count; qOSg!aft{Q
import tot.db.DBUtils; '"<6.,Ae
import java.sql.*; >*-FV{{
/** `(1K
* 0O\SU"bP
* @author U\veOQ;mW
*/ ZA Jp%
public class CountControl{ JJltPGT~Oa
private static long lastExecuteTime=0;//上次更新时间 |J+(:{}~
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 !).}u,*'no
/** Creates a new instance of CountThread */ i^_#%L
public CountControl() {} "p/j; 6H
public synchronized void executeUpdate(){ #l4)HV
Connection conn=null; 'WI^nZM
PreparedStatement ps=null; FuUD 61JHY
try{ N0K){
conn = DBUtils.getConnection(); R*oXmuOsYA
conn.setAutoCommit(false); rQOWLg!"
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 6\u!E~zy
for(int i=0;i<CountCache.list.size();i++){ ly4s"4v
CountBean cb=(CountBean)CountCache.list.getFirst(); bn(`O1r[(
CountCache.list.removeFirst(); 7}GK%H-u
ps.setInt(1, cb.getCountId()); :-iMdtm
ps.executeUpdate();⑴ ]l@ qra
//ps.addBatch();⑵ +B'8|5tPX
} 6
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//int [] counts = ps.executeBatch();⑶ rrnNn'
conn.commit(); zOHypazOTq
}catch(Exception e){ 9D 0dg(
e.printStackTrace(); kF{*(r=.o
} finally{ uK("<u|
try{ }C
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if(ps!=null) { O1D6^3w
ps.clearParameters(); ="%W2
ps.close(); .}k(L4T|=
ps=null; R8-^RvG
} 7l."b$U4yv
}catch(SQLException e){} ]WUC:6x
DBUtils.closeConnection(conn); E15vq6 DKF
} nRb^<cZf
} ?\/qeGW6G
public long getLast(){ 6*nAo8gl
return lastExecuteTime; /ahNnCtu?1
} Eq^uKi
public void run(){ &[a Tw{2
long now = System.currentTimeMillis(); C#i UP|7hh
if ((now - lastExecuteTime) > executeSep) { =s}Xy_+:
//System.out.print("lastExecuteTime:"+lastExecuteTime); #.5vC5
//System.out.print(" now:"+now+"\n"); xMs]Hs
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); s$DrR
lastExecuteTime=now; B|%tE{F
executeUpdate(); Ogg#jx(4
} W3&tJ8*3
else{ `7+j0kV)
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 7OVbP%n)d2
} V&Mf:@y
} i3mAfDF
} .wK1El{bf
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 ,>LRa
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类写好了,下面是在JSP中如下调用。 LS.r%:$mb
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<% ekQrW%\3
CountBean cb=new CountBean(); ] c}91
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 7ODaX.t->
CountCache.add(cb); WxGSv#u
out.print(CountCache.list.size()+"<br>"); XidxNPz0^
CountControl c=new CountControl(); +`bC%\T8?
c.run(); DFe;4BdC
out.print(CountCache.list.size()+"<br>"); 8v
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%>