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: I8wVvs;k
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CountBean.java @9P9U`ZP
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/* H4",r5qw:
* CountData.java 6#63D>OWp
* 4U1fPyt
* Created on 2007年1月1日, 下午4:44 4!W?z2ly~R
* t-m,~Io W
* To change this template, choose Tools | Options and locate the template under &zDFf9w2{
* the Source Creation and Management node. Right-click the template and choose }(IDPaJ
* Open. You can then make changes to the template in the Source Editor. BJ2W}R
*/ oa|*-nw
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package com.tot.count; _@?Jx/`;bk
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/** 5Kxk9{\8
* rSCX$ @@F
* @author `%:(IGxz
*/ Yzx0 [_'u
public class CountBean { >V=@[B(0
private String countType; *J5euA5=
int countId; "r3s'\
/** Creates a new instance of CountData */ 7n]%`Yb
public CountBean() {} nM}`H'0
public void setCountType(String countTypes){ $6%;mep
this.countType=countTypes; #mxfU>vQ:
} ^moIMFl
public void setCountId(int countIds){ Gl:T
this.countId=countIds; _jKVA6_E
} rZ4<*Zegv
public String getCountType(){ T1[ZrY'0
return countType; "<R
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} |VF"Cjw?
public int getCountId(){ X,CFY
return countId; LMj'?SuH
} nECf2>Yp v
} N2Hb19/k
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CountCache.java ofv
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/* S*@0%|Q4r
* CountCache.java U MIZ:*j
* T<GD !j(
* Created on 2007年1月1日, 下午5:01 7OHw/-j\
* nOzTHg8
* To change this template, choose Tools | Options and locate the template under |H@p^.;
* the Source Creation and Management node. Right-click the template and choose glIIJ5d|,
* Open. You can then make changes to the template in the Source Editor. IcA~f@
*/ eZ$1|Sj]j
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package com.tot.count; \,t<{p_Q
import java.util.*; xGk4KcxKs
/** H43D=N&
* ,6pH *b$
* @author N'.+ezZ;h
*/ |:BYOxAYZ8
public class CountCache { wajhFBJ
public static LinkedList list=new LinkedList(); izo
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/** Creates a new instance of CountCache */ )C6 7qY[P
public CountCache() {} 9F!&y-
public static void add(CountBean cb){ ~[6|VpGc:
if(cb!=null){ !qv;F?2
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list.add(cb); k] YGD
} fdHxrH>*
} S`.-D+.68
} yBKlp08J
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CountControl.java IbwRb
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/* I/|n
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* CountThread.java " V2$g
* C>ZeG
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* Created on 2007年1月1日, 下午4:57 !-~(*tn
* [GM<Wt0
* To change this template, choose Tools | Options and locate the template under ^q2zqC
* the Source Creation and Management node. Right-click the template and choose ywte\}
* Open. You can then make changes to the template in the Source Editor. ZeV)/g,w
*/ v21?
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package com.tot.count; !~v>&bCG>9
import tot.db.DBUtils; (P8oXb+%
import java.sql.*; &i RX-)^u
/** r U5'hK
* t,nB`g?
* @author #1R
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*/ gvYs<,:
public class CountControl{ B[50{;X
private static long lastExecuteTime=0;//上次更新时间 uD3_'a
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 e vuP4-[y
/** Creates a new instance of CountThread */ =<xbE;,0
public CountControl() {} k=_@1b-
public synchronized void executeUpdate(){ W -&5
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Connection conn=null; _Oq\YQb v
PreparedStatement ps=null; ~V)E:(
try{ ;_\P;s
conn = DBUtils.getConnection(); p60D{UzU
conn.setAutoCommit(false); Eq{TZV
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Pq%cuT%
for(int i=0;i<CountCache.list.size();i++){ { VO4""m
CountBean cb=(CountBean)CountCache.list.getFirst(); ?Q2pD!L{
CountCache.list.removeFirst(); RGmpkQEp
ps.setInt(1, cb.getCountId()); @Iu-F4YT
ps.executeUpdate();⑴ l-EQh*!j
//ps.addBatch();⑵ T(F8z5s5
} =ndKG5
//int [] counts = ps.executeBatch();⑶ ak[)+_k_
conn.commit(); @( l`_Wx
}catch(Exception e){ ?f&I"\y
e.printStackTrace(); :~Y$\Ww(~
} finally{ R3A^VE;qP
try{ XT"c7]X
if(ps!=null) { Gy%e%'
ps.clearParameters(); 1O4"MeF
ps.close(); 0
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ps=null; Q2Rj0E`
} ) /'s&
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}catch(SQLException e){} ^cm^JyS)
DBUtils.closeConnection(conn); ri
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} IIkJ"Qg.
} f'dI"o&^/d
public long getLast(){ Km7
return lastExecuteTime; $(U|JR@
} 9j`-fs@:
public void run(){ |{T2|iJI
long now = System.currentTimeMillis(); }__+[-
if ((now - lastExecuteTime) > executeSep) { A$cbH.
//System.out.print("lastExecuteTime:"+lastExecuteTime); h;->i]
//System.out.print(" now:"+now+"\n"); -yeT $P&|
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ZI7<E
lastExecuteTime=now; )RFeF!("
executeUpdate(); Sqs`E[G*
} x#D=?/~/Kv
else{ 3
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); "f_Z.6WMY
} a2TC,
} }|,y`ui\
} cht#~d
//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 ZtVa*xl
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类写好了,下面是在JSP中如下调用。 gZ3!2T>
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<% %L3]l
CountBean cb=new CountBean(); Pp2)P7
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); N;Bal/kd2
CountCache.add(cb); 'Nh^SbD+_|
out.print(CountCache.list.size()+"<br>"); zKNk(/y
CountControl c=new CountControl(); `Nj|}^A
c.run(); Bh?;\D'YC
out.print(CountCache.list.size()+"<br>"); ,ME9<3Ac
%>