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: NG=-NxEcN
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CountBean.java +.PxzL3?
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/* )
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* CountData.java H7Rx>h_
* ?=msH=N<l
* Created on 2007年1月1日, 下午4:44 /U*C\ xMm
* DCO\c9
* To change this template, choose Tools | Options and locate the template under `g?Negt\v
* the Source Creation and Management node. Right-click the template and choose oSKXt}sh
* Open. You can then make changes to the template in the Source Editor. xj)F55e?
*/ F{e@W([
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package com.tot.count; oCv.Ln1;Z
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/** Wis~$"
* 3pROf#M
* @author n38p !oS
*/ %IA\pSE
public class CountBean { wU36sCo
private String countType; ~vhE|f
int countId; Q$W
/** Creates a new instance of CountData */ p`dU2gV
public CountBean() {} 2 a)xTA#
public void setCountType(String countTypes){ FX&~\kmV'j
this.countType=countTypes; &BLJT9Frx
} 1-uxC^u?|#
public void setCountId(int countIds){ 76Cl\rV
this.countId=countIds; :S83vE81WK
} ~Ffo-Nd-
public String getCountType(){ s c,Hq\$&
return countType; 4Z=_,#h4.
} (,\+tr8r8
public int getCountId(){ `?rSlR@+[I
return countId; U}[d_f
} bH9kj/q\b
} UhWNl]Z
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CountCache.java uAq~=)F>,
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/*
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* CountCache.java mDABH@R
* #G|RnV%t$~
* Created on 2007年1月1日, 下午5:01 [b%D3-}'
* 9&2O9Nz6
* To change this template, choose Tools | Options and locate the template under X7MM2V
* the Source Creation and Management node. Right-click the template and choose lv<*7BCp
* Open. You can then make changes to the template in the Source Editor. 0S_~ \t
*/ dL 1tl
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package com.tot.count; uBKgcpvTs
import java.util.*; ~H_/zK6e
/** nNV'O(x}
* =:Fc;n>c<K
* @author Fnv;^}\z
*/ %N6A+5H
public class CountCache { ~
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public static LinkedList list=new LinkedList(); ~$cV:O7
/** Creates a new instance of CountCache */ \ZFGw&yN
public CountCache() {} KP^V>9q
public static void add(CountBean cb){ <z&/L/bl"
if(cb!=null){ @V sG'
list.add(cb); H5B:;g@
} qJs<#MQ2
} ZY55|eE
} GW@;}m(
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CountControl.java X/!o\yyT
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/* wE>\7a*P%
* CountThread.java iL&fgF"'
* 6r0krbN
* Created on 2007年1月1日, 下午4:57 %D34/=(X
* -UEZ#Q
* To change this template, choose Tools | Options and locate the template under TDKki(o=~
* the Source Creation and Management node. Right-click the template and choose BLdvyVFx
* Open. You can then make changes to the template in the Source Editor. ]i)c{y
*/ }O5i/#.lR
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package com.tot.count; Id'-&tYG
import tot.db.DBUtils; =l;ewlU
import java.sql.*; Wx}8T[A}
/** X1|njJGO1
* yCR?UH;
* @author WIT>!|w_
*/ \)N9aV
public class CountControl{ \;3~a9q%
private static long lastExecuteTime=0;//上次更新时间 jl$ece5v
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 YeL#jtC
/** Creates a new instance of CountThread */ o Q2Fjj
public CountControl() {} `Bp.RXsd*
public synchronized void executeUpdate(){ )gIKH{JYL
Connection conn=null; 8 &LQzwa
PreparedStatement ps=null; +b<FO+E_
try{ $E~`\o%Ev
conn = DBUtils.getConnection(); A*2jENgci
conn.setAutoCommit(false); X,_2FJv
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); cWaSn7p !X
for(int i=0;i<CountCache.list.size();i++){ I\{ 1u
CountBean cb=(CountBean)CountCache.list.getFirst(); XGWSdPJLr
CountCache.list.removeFirst(); H3^},.
ps.setInt(1, cb.getCountId()); n8
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ps.executeUpdate();⑴ , , OW
//ps.addBatch();⑵ !8d{q)JZ
} gMmaK0uhS
//int [] counts = ps.executeBatch();⑶ kk@fL
conn.commit(); SCHP L.n
}catch(Exception e){ vn!3l1\+J
e.printStackTrace(); 5h-SCB>P
} finally{ Tod&&T'UW
try{ GqvpA#
i
if(ps!=null) { \BTODZ:h
ps.clearParameters(); zuad~%D<I
ps.close(); 4#xDgxg\f
ps=null; T|e u
} 9igiZmM
}catch(SQLException e){} 4y?n
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DBUtils.closeConnection(conn); nu[ML
} :Zbg9`d*
} jh%Eq+#S
public long getLast(){ x(6SG+Kr
return lastExecuteTime; Smn;(K
} gnOt+W8
public void run(){ @ $ ;q;
long now = System.currentTimeMillis(); hHGoP0/o
if ((now - lastExecuteTime) > executeSep) { >}8j+t&T
//System.out.print("lastExecuteTime:"+lastExecuteTime); Lv;^My
//System.out.print(" now:"+now+"\n"); %KhI>O<
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 36Zf^cFJ
lastExecuteTime=now; 9@(PWz=`?
executeUpdate(); D9=KXo^
} JN-y)L/>
else{ H9`)BbR
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); %KlrSo
} x.!V^HQSN
} ZF9z~9
} !Vn\u
//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 ghG**3xr
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类写好了,下面是在JSP中如下调用。 *SDs;kg
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<% .+3g*Dv{&
CountBean cb=new CountBean(); ?W?c1>
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); df4A RP+
CountCache.add(cb); +US!YU
out.print(CountCache.list.size()+"<br>"); :Uzm
CountControl c=new CountControl(); M#4pE_G
c.run(); 9}!qR|l3nR
out.print(CountCache.list.size()+"<br>"); !*dI|k
%>