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: 4+$<G /K
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CountBean.java ?0DCjh8We
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/* 0{BPT>'
* CountData.java ^ B=x-G.
* <{[AG3/Zj4
* Created on 2007年1月1日, 下午4:44 h<Yn0(.
* &oWWc$
* To change this template, choose Tools | Options and locate the template under Hm-+1Wx
* the Source Creation and Management node. Right-click the template and choose B(:Kw;r?
* Open. You can then make changes to the template in the Source Editor. 6pLB`1[v
*/ --Dw
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package com.tot.count; awHfd5nRS
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/** fB3O zff
* zt[TShD^
* @author l^uP?l"
*/ $Y,,e3R3
public class CountBean { j<szQ%tJlI
private String countType; _>dqz(8#
int countId; >tr_Ypfv,c
/** Creates a new instance of CountData */ /raM\EyrlP
public CountBean() {} = EyxM
public void setCountType(String countTypes){ Xd)ba9{
this.countType=countTypes; 9x;/q7
} OV7vwj/-
public void setCountId(int countIds){ ^W_}Gd<-#Y
this.countId=countIds; o*qEAy?
} Zj<oh8
public String getCountType(){ Zv7@
return countType; c72Oy+#
} q-o=lU"
public int getCountId(){ #_2V@F+,
return countId; [9BlP
} "2HRuqf
} d%t]:41=Z
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CountCache.java $-=aqUU
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/* )_GM&-
* CountCache.java ]WWre},
* !Ya
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* Created on 2007年1月1日, 下午5:01 ~_8Ve\Y^ /
* B
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* To change this template, choose Tools | Options and locate the template under at,Xad\j
* the Source Creation and Management node. Right-click the template and choose tPO.^
* Open. You can then make changes to the template in the Source Editor. ?9H7Twi+T
*/ **_VNDK+
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package com.tot.count; +A~lPXAXW
import java.util.*; #xW%RF
/** 'x+0
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* 2}$Vi$
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* @author c`doR(oZ
*/ **! lV]/
public class CountCache { +GP"9S2%R
public static LinkedList list=new LinkedList(); X-:Ni_O\ty
/** Creates a new instance of CountCache */ M\\TQ(B
public CountCache() {} 2Mu-c:1
public static void add(CountBean cb){ Ef%8+_
if(cb!=null){ iN`/pW/JE
list.add(cb); EOtrrfT&
} Pk8L-[&v
} 2*K0~ b`
} 0qG[hxt%
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CountControl.java KS*W<_I
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/* *XniF~M
* CountThread.java nz+o8L,
* 1yX&iO^d
* Created on 2007年1月1日, 下午4:57 ;4 ?%k )
* 7w>"M
* To change this template, choose Tools | Options and locate the template under ,yV
pB)IQ
* the Source Creation and Management node. Right-click the template and choose oYJ&BPuA'
* Open. You can then make changes to the template in the Source Editor. \lKQDct. -
*/ LaN4%[;X1-
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package com.tot.count; 5Hr(9)
import tot.db.DBUtils; (
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import java.sql.*; ;Ic3th%u
/** U?$v1 ||
* a P{xMB#1h
* @author B1nb23SY T
*/ B{)Du
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public class CountControl{ ,Yi =s;E
private static long lastExecuteTime=0;//上次更新时间 Vg:P@6s
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 aj(M{gFq~
/** Creates a new instance of CountThread */ PDD` eK}Fj
public CountControl() {} D|e 6$O5o
public synchronized void executeUpdate(){ 6b<t|zb
Connection conn=null; AQQj]7Y
PreparedStatement ps=null; JSGUl4N
try{ De>pIN;B>
conn = DBUtils.getConnection(); RK rBHqh@
conn.setAutoCommit(false); cLR8U1k'
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Ae ue:u>
for(int i=0;i<CountCache.list.size();i++){ M\`6H8aLn
CountBean cb=(CountBean)CountCache.list.getFirst(); 6bHj<6>MX
CountCache.list.removeFirst(); .*Hv^_
ps.setInt(1, cb.getCountId()); A]H+rxg
ps.executeUpdate();⑴ ^<y$+HcH
//ps.addBatch();⑵ < "~k8:=4
} ~-W.yg6D{
//int [] counts = ps.executeBatch();⑶ m.V mS7_I
conn.commit(); 5.GBd_;
}catch(Exception e){ <}4|R_xY#
e.printStackTrace(); 6@l:(-(j2A
} finally{ Z: Kob
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try{ zEO
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if(ps!=null) { Ho\+xX
ps.clearParameters(); //wmJ |
ps.close(); ( _nkscf
ps=null; jU4Ir{f
} zcxG%? Q
}catch(SQLException e){} OVj,qL)
DBUtils.closeConnection(conn); 8De
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} o,aI<5"
} e;!<3b
public long getLast(){ NoKYHN^*w
return lastExecuteTime; i^QcW!X&
} (qPZEZKx
public void run(){ %+pXzw`B
long now = System.currentTimeMillis(); <78>6u/W%
if ((now - lastExecuteTime) > executeSep) { !2{MWj
//System.out.print("lastExecuteTime:"+lastExecuteTime); 58v5Z$%--
//System.out.print(" now:"+now+"\n"); A@DIq/^xM
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Qz$.t>@V=
lastExecuteTime=now; YO,GZD`-o
executeUpdate(); pkk0?$l",
} niA{L:4
else{ 7s.sbP~
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); gl!3pTC
} VFYJXR{
} GbL,k?ey
} 8=2)I.
//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 D~mGv1t"
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类写好了,下面是在JSP中如下调用。 *S=v1 s/
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<% ~?L. n:wu
CountBean cb=new CountBean(); i,)kI
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); F'*{Fk
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CountCache.add(cb); ;c;;cJc!
out.print(CountCache.list.size()+"<br>"); ]]7s9PCN
CountControl c=new CountControl(); CX1'B0=\r
c.run(); 'E7|L@X"r
out.print(CountCache.list.size()+"<br>"); |20p#]0E+
%>