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: }s9eRmJs
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CountBean.java ,@\$PyJ
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/* e8Ul^]
* CountData.java y cT@D/
* EgE%NY~
* Created on 2007年1月1日, 下午4:44
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* _Wb3,E a=
* To change this template, choose Tools | Options and locate the template under 3]46qk'
* the Source Creation and Management node. Right-click the template and choose U4$}8~o4
* Open. You can then make changes to the template in the Source Editor. V4["+Y
*/ 2|6E{o
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package com.tot.count; A$JL"~R
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/** -`f 1l8LD2
* B;vpG?s{9
* @author u5'jIqlU
*/ zfsGf'U
public class CountBean { KUV(vAY,
private String countType; KbXENz&C
int countId; Zra P\ ?
/** Creates a new instance of CountData */ > w-fsL
public CountBean() {} M?gc&2Y
public void setCountType(String countTypes){ 6L/`
this.countType=countTypes; B[$L)y'-;
} 1B0+dxN`
public void setCountId(int countIds){ hifC.guK
this.countId=countIds; r|ID]}w
} zObrp
public String getCountType(){ af>^<q
return countType; -"CXBKHb
} {W' 9k
public int getCountId(){ nOm-Yb+F
return countId; )c<X.4
} ;irAq|
} d#U~>wr
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CountCache.java Zl\$9Q_
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/* m\.(-
* CountCache.java PK&\pkX
* P+Q}bTb8
* Created on 2007年1月1日, 下午5:01 C}=9m
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* ">M:6\B
* To change this template, choose Tools | Options and locate the template under Qn!KL0w
* the Source Creation and Management node. Right-click the template and choose '89nyx&W
* Open. You can then make changes to the template in the Source Editor. (7*((
*/ <hBd
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package com.tot.count; {3qlx1w
import java.util.*; F@l d#O
/** 8#ZF<BY
* e6i m_ Tk
* @author 9>-]*7
*/ ,Zva^5
public class CountCache { ^|lw~F
public static LinkedList list=new LinkedList(); wv.HPmq
/** Creates a new instance of CountCache */ 2u%YRrp
public CountCache() {} (7A- cC
public static void add(CountBean cb){ M`49ydh&
if(cb!=null){ j2`%sBo
list.add(cb); V'8Rz#Gc5
} r!&}4lHYi
} % pQi}x
} I\~sE Jwj
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CountControl.java zF@/8#
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/* l&_PsnU
* CountThread.java 560`R>
* ]-{A"tJ
* Created on 2007年1月1日, 下午4:57 t8f:?
* 62 9g_P)
* To change this template, choose Tools | Options and locate the template under fn,
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* the Source Creation and Management node. Right-click the template and choose .OZ\s%h;
* Open. You can then make changes to the template in the Source Editor. b6d}<b9#
*/ E[Bj+mX9
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package com.tot.count; yqKSaPRA
import tot.db.DBUtils; )S^[b2P]y_
import java.sql.*; Vtv1{/@+c
/** v!j%<H`NI
* i$6o>V6
* @author 9;ie[sU:u
*/ jGEmf<q&u
public class CountControl{ [8'^"
private static long lastExecuteTime=0;//上次更新时间 Y'Yu1mH)
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 "%ZAL\x
/** Creates a new instance of CountThread */ 8 Y))/]R
public CountControl() {} N6BEl55 &
public synchronized void executeUpdate(){ +R',$YzD
Connection conn=null; nq:'jdY5|
PreparedStatement ps=null; A2''v3-h8
try{ F- {hXM
conn = DBUtils.getConnection(); kC
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conn.setAutoCommit(false); gR${S|Z#u4
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); &sooXKlv|
for(int i=0;i<CountCache.list.size();i++){ yL_\&v
CountBean cb=(CountBean)CountCache.list.getFirst(); XblZlWP#
CountCache.list.removeFirst(); _xGC0f (
ps.setInt(1, cb.getCountId()); %']`t-N8
ps.executeUpdate();⑴ ]\F}-I[
//ps.addBatch();⑵ p7Z/%~0v:
} "DSRy D0M
//int [] counts = ps.executeBatch();⑶ 11B8 LX
conn.commit(); $9ys!
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}catch(Exception e){ ]Cp`qayct
e.printStackTrace(); kudXwj
} finally{ =D
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try{ EMf"rGXu(
if(ps!=null) { [Uw3.CVh
ps.clearParameters(); {j%7/T{
ps.close(); a6'T]DW0W
ps=null; X<d`!,bn@
} 6|Xm8,]yRw
}catch(SQLException e){} yGC3B00Z
DBUtils.closeConnection(conn); ztC>*SX
} 8aI^vP"7`=
} w
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public long getLast(){ .50ql[En
return lastExecuteTime; ?&bB?mg\
} Wb;D9Z
public void run(){ xzBUm
long now = System.currentTimeMillis(); (/C
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if ((now - lastExecuteTime) > executeSep) { c3J12+~;
//System.out.print("lastExecuteTime:"+lastExecuteTime); '
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//System.out.print(" now:"+now+"\n"); \vgM`32<
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); qcoTt~\
lastExecuteTime=now; Jm-bE 8b
executeUpdate();
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} !JbWxGN`jn
else{ *#j_nNM4
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); x<=R?4@rq
} :_pn|
} zE?@_p1gei
} WNF#eM?[a
//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 U4h5K}j4
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类写好了,下面是在JSP中如下调用。 pQk@
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<% Ly]J-BTe
CountBean cb=new CountBean(); Zo@
cb.setCountId(Integer.parseInt(request.getParameter("cid")));
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CountCache.add(cb); <P#:dS%r
out.print(CountCache.list.size()+"<br>"); y0,>_MS
CountControl c=new CountControl(); mJ+mTA5bW
c.run(); !CR#Fyt+9
out.print(CountCache.list.size()+"<br>"); P9q ZjBS
%>