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: S;sggeP7,
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CountBean.java 8u
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/* _)
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* CountData.java 3 GmU$w
* U+>!DtOYK
* Created on 2007年1月1日, 下午4:44 X<dQq`kZ
* `CA-s
* To change this template, choose Tools | Options and locate the template under ^\Tde*48
* the Source Creation and Management node. Right-click the template and choose P+ONQN|
* Open. You can then make changes to the template in the Source Editor. `[3Iz$K=
*/ _U( b
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package com.tot.count; ,l^; ZE
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/** |=L~>G
* jq:FDyOAW
* @author F$QN>wPpM
*/ Cx2s5vJX4p
public class CountBean { wi^zXcVj
private String countType; $"1Unu&P
int countId; Aw9se"d
/** Creates a new instance of CountData */ =)5O(h
public CountBean() {} ((&_m9a
public void setCountType(String countTypes){ h}r*
this.countType=countTypes; rCU f,)
} Z
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public void setCountId(int countIds){ GjN/8>/
this.countId=countIds; @[h)M3DFd
} ^
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public String getCountType(){ s kC*
return countType; 4scY8(1
} MkgeECMf
public int getCountId(){ mz$)80ly
return countId; /\34o{
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CountCache.java ^0vK >
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/* q}P< Ejq}
* CountCache.java |YCGWJaci
* qPqpRi
* Created on 2007年1月1日, 下午5:01 n6D9f~8"
* {U@&hE
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* To change this template, choose Tools | Options and locate the template under cdiDfiE
* the Source Creation and Management node. Right-click the template and choose l)tK/1 W
* Open. You can then make changes to the template in the Source Editor. ,{==f7|w
*/ v zgR3r
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package com.tot.count; reseu*5
import java.util.*; h&@A'om~
/** ZGO%lkZ.
* 8g0By;h;
* @author g}
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*/ S.&=>
public class CountCache { =j#1HI=Fe
public static LinkedList list=new LinkedList(); D=Ia$O0.
/** Creates a new instance of CountCache */ ln4gkm<]t
public CountCache() {} C".nB12
public static void add(CountBean cb){ f$#--*
if(cb!=null){ gS{hfDpk,h
list.add(cb);
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} /$
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} vF
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} c1 aCN
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CountControl.java wJ#fmQXKJ5
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/* 7^1yZ1(
* CountThread.java KglL@V7
* YZ>L\
* Created on 2007年1月1日, 下午4:57 >K:| +XbH
* ffyDi 1Q
* To change this template, choose Tools | Options and locate the template under );EW(7KeL
* the Source Creation and Management node. Right-click the template and choose XG_h\NIL
* Open. You can then make changes to the template in the Source Editor. %]NaHf
*/ pT3p!/pl3
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package com.tot.count; .axJ '*~W
import tot.db.DBUtils; 7>
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import java.sql.*; <[iw1>
/** CB V(H$d
* ,liFo.kT8%
* @author MI8f(ZJK5
*/ ZqT8G
public class CountControl{ R\DdU-k
private static long lastExecuteTime=0;//上次更新时间 B=)&43)\
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 t6-He~
/** Creates a new instance of CountThread */ fKEZlrw
public CountControl() {} Cg{V"B:
public synchronized void executeUpdate(){ 9vIqGz-o
Connection conn=null; lO^Ly27
PreparedStatement ps=null; y[QQopy4:
try{ 2stBW5v3
conn = DBUtils.getConnection(); ((KNOa5
conn.setAutoCommit(false); bm/pLC6%.
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); cyYsz'i m
for(int i=0;i<CountCache.list.size();i++){ 0_nY70B
CountBean cb=(CountBean)CountCache.list.getFirst(); Tx+!D'>
CountCache.list.removeFirst(); "rxhS;
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ps.setInt(1, cb.getCountId()); 7oUecyoj
ps.executeUpdate();⑴ kpF")0qr
//ps.addBatch();⑵ R`M>w MLH
} &n6'r^[D
//int [] counts = ps.executeBatch();⑶ B$ty`/{w,B
conn.commit(); mEK0ID\
}catch(Exception e){ vbFi#|EU
e.printStackTrace(); yC%zX}5
} finally{ \tv^],^`
try{ tc-pVw:TV
if(ps!=null) { t<8vgdD
ps.clearParameters(); FXLY*eRk
ps.close(); TpnJm%9`)t
ps=null; 6( #fGH&[
} K|n%8hRy
}catch(SQLException e){} #fB&Hv #s7
DBUtils.closeConnection(conn); U(xN}Y?
} 8w,+Y]X<P[
} 9Yu63s ia
public long getLast(){ ~!V5Ug_2
return lastExecuteTime;
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} >WYiOXYv
public void run(){ 1P8XVI'
long now = System.currentTimeMillis(); ^a>3U l{
if ((now - lastExecuteTime) > executeSep) { QuB`}rfLf
//System.out.print("lastExecuteTime:"+lastExecuteTime); +#* F"k(
//System.out.print(" now:"+now+"\n"); #6g9@tE
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); >z{*>i,m1
lastExecuteTime=now; Bh`Y?S
executeUpdate(); F_^)zss
} 0`WjM2So
else{ JAt$WW{
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Rs$fNW@P
} 8|]r>L$Wk
} 1gK<dg
} c>SFttbU
//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 5Z8Zb.
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类写好了,下面是在JSP中如下调用。 ^|^yw gK
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<% c<k=8P
CountBean cb=new CountBean(); \@\r`=WgB
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 2wCSjAWWh(
CountCache.add(cb); JD\yl[ac%
out.print(CountCache.list.size()+"<br>"); cWp5' e]A
CountControl c=new CountControl(); W;Pdbf"
c.run(); 3VI[*b
out.print(CountCache.list.size()+"<br>"); Fx@ovI- 5
%>