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: _j< K=){
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CountBean.java B9NWW6S
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/* tt0f-:#
* CountData.java @zU6t|mhz
* .J)I | '
* Created on 2007年1月1日, 下午4:44 6W]9$n\"?
* ABD)}n=%c
* To change this template, choose Tools | Options and locate the template under e?JW
* the Source Creation and Management node. Right-click the template and choose
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* Open. You can then make changes to the template in the Source Editor. `w.n]TR
*/ _"bHe/'CI
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package com.tot.count; mID"^NOi#
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/** c'%-jG)\
* SYCEQ5
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* @author _B/dWA,P
*/ >z%&xgOa
public class CountBean { ]n_
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private String countType; GO`Ru 8
int countId; $\]&rZVi
/** Creates a new instance of CountData */ Ye2 {f"F
public CountBean() {} PIu1+k.r?
public void setCountType(String countTypes){ VUPXO
this.countType=countTypes; "alyfyBu'M
} x4;"!Kq\
public void setCountId(int countIds){ {^CY..3
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this.countId=countIds; y(CS5v#FG
} |iE50,
public String getCountType(){ dQV;3^iUY
return countType; YQHw1
} [|(N_[E|6
public int getCountId(){ YKH\rN6X
return countId; QdL`|
} o0ifp=V
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} HCyv ]LR
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CountCache.java MZSy6v
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/* Z>)Bp/-
* CountCache.java X*/ho
* wO'TBP
* Created on 2007年1月1日, 下午5:01 YG@t5j#b
* ^p[rc@+
* To change this template, choose Tools | Options and locate the template under ?OcJ)5C4
* the Source Creation and Management node. Right-click the template and choose UTH*bL5/J2
* Open. You can then make changes to the template in the Source Editor. kCR_tn
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*/ N/%WsQp
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package com.tot.count; uE%r/:!k4$
import java.util.*; ([SU:F!uW(
/** }001K
* bCo7*<I4
* @author fZ0M%f
*/ =G7m)!
public class CountCache { Si8pzd
public static LinkedList list=new LinkedList(); }uJu>'1[G
/** Creates a new instance of CountCache */ *5%d XixN
public CountCache() {} [x+FcXb
public static void add(CountBean cb){ +S>j0m<*
if(cb!=null){ #$18*?tLv|
list.add(cb); cAY: AtD
} _ FpTFfB
} Y w^m
} wSa)*]%
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CountControl.java A#.edVj.g4
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/* ^hc!FD
* CountThread.java a1C{(f)
* c0,0`+2~
* Created on 2007年1月1日, 下午4:57 pT=JP> nd^
* ,}3
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* To change this template, choose Tools | Options and locate the template under W42iu"@
* the Source Creation and Management node. Right-click the template and choose S2HcG
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* Open. You can then make changes to the template in the Source Editor. (;T^8mI2
*/ :r{<zd>;
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package com.tot.count; F*IzQ(#HW
import tot.db.DBUtils; >AVVEv18
import java.sql.*; vdAr|4^qB
/** #|L8tuWW
* ,:%CB"J
* @author [pbo4e,4O
*/ PVe
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public class CountControl{ ULs\+U
private static long lastExecuteTime=0;//上次更新时间 ;_c;0)
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 1oR7iD^
/** Creates a new instance of CountThread */ Zq+v6fk_Mn
public CountControl() {} >3p\m
public synchronized void executeUpdate(){ S\:P-&dC
Connection conn=null; ZP@
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PreparedStatement ps=null; wPQH(~k:
try{ cG[l!Z
conn = DBUtils.getConnection(); 0)Uce=t`
conn.setAutoCommit(false); 8&GBV_`I
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 4{y)TZ
for(int i=0;i<CountCache.list.size();i++){ !%CWZZ 6u
CountBean cb=(CountBean)CountCache.list.getFirst(); e7^mmm
CountCache.list.removeFirst(); ~xkeuU
ps.setInt(1, cb.getCountId()); J1( 9QN[w
ps.executeUpdate();⑴ S0zD"T
//ps.addBatch();⑵ ^uKwB;@
} ZGexdc%
//int [] counts = ps.executeBatch();⑶ wxKX{Bs
conn.commit(); 8EW_V$>R
}catch(Exception e){ f.D?sH An
e.printStackTrace(); MqW7cjg
} finally{ dq(uVW^&ae
try{ azCf
if(ps!=null) { \y97W&AN
ps.clearParameters(); gH12[Us'`
ps.close(); '~5LY!H(pT
ps=null; MI/MhkS
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} a!a-b~#cx
}catch(SQLException e){} T-.%
DBUtils.closeConnection(conn); Bal$+S
} /Lfm&;
} kjIAep0rT
public long getLast(){ ^yW L,$
return lastExecuteTime; 6</xL9#/
} zBCtd1Xrni
public void run(){ A
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long now = System.currentTimeMillis(); 3x`|
if ((now - lastExecuteTime) > executeSep) { * aN
//System.out.print("lastExecuteTime:"+lastExecuteTime); ,k24w7K%d
//System.out.print(" now:"+now+"\n"); s3z$e+A8
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); IdzxS
lastExecuteTime=now; v:IpMU-+\
executeUpdate(); WffQ :L?
} &-;4.op
else{ zNs55e.rx
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); xcd#&
} S=MEG+Ad
} ?:vv50
} RiDJ> 6S
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 _dqzB$JV
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类写好了,下面是在JSP中如下调用。 Zq^At+8+
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<% [A~y%bI"
CountBean cb=new CountBean(); i`(XLi}k
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); -)w@f~Q
CountCache.add(cb); =m!-m\B/
out.print(CountCache.list.size()+"<br>"); Dt}JG6 S
CountControl c=new CountControl(); B-xGX$<z
c.run(); p,
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out.print(CountCache.list.size()+"<br>"); E%yNa]\P
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