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: bzk@6jR1
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CountBean.java s#)fnNQ,
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/* d@7
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* CountData.java Gow_a'
* *vCJTz
* Created on 2007年1月1日, 下午4:44 E:&=A 4%
* p!|Wp
* To change this template, choose Tools | Options and locate the template under >Ah [uM
* the Source Creation and Management node. Right-click the template and choose Eae]s8ek9
* Open. You can then make changes to the template in the Source Editor. Ls5|4%+&
*/ 3PpycJ}
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package com.tot.count; QI=",vmau
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/** V. =! ^0'A
* ;[ pyKh
* @author TN.mNl%
*/ eMPi ho
public class CountBean { zK k;&y|{
private String countType; k~`pV/6
int countId; `L]cJ0tAs
/** Creates a new instance of CountData */ rzLpVpTaz
public CountBean() {} Y71io^td~j
public void setCountType(String countTypes){ *]W{83rXQ
this.countType=countTypes; w/~,mzM"
} (](:0H
public void setCountId(int countIds){ yJppPIW^
this.countId=countIds; dE.R$SM
} (pREo/ T
public String getCountType(){ < :<E~anH
return countType; #=OKY@z/
} :nCGqg
public int getCountId(){ xl5mI~n_~
return countId; +]Po!bN@@
} ht!o_0{~
} a+uSCs[C
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CountCache.java ['tGc{4
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/* {tOu+zy
* CountCache.java R',Q)<
* ,=Xr'7w,
* Created on 2007年1月1日, 下午5:01 *6df|q
* yS@c2I602
* To change this template, choose Tools | Options and locate the template under q$(aMO&J
* the Source Creation and Management node. Right-click the template and choose k9~NIvnB`
* Open. You can then make changes to the template in the Source Editor. 8l~]}2LAs
*/ ltwX-
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package com.tot.count; brl(7_2
import java.util.*; .Quu_S_vH
/** i,8h
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* ;8'hvc3i$
* @author =;l.<{<VH
*/ /[q6"R!uMz
public class CountCache { z{]$WVs:^
public static LinkedList list=new LinkedList(); CJ8X Ky
/** Creates a new instance of CountCache */ #@w8wCj
public CountCache() {} +j1s*}8
public static void add(CountBean cb){ VY<$~9a&1
if(cb!=null){ 9 ]c2ub7
list.add(cb); FWq+'GkSV
} WJ<nc+/v:
} M56^p,
} ]e$mTRi*
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CountControl.java )iNMjg
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/* WldlN?[j
* CountThread.java }rj.N98
* 4c_TrNwP
* Created on 2007年1月1日, 下午4:57 V:fz
* =ps3=D
* To change this template, choose Tools | Options and locate the template under 9.{u2a\
* the Source Creation and Management node. Right-click the template and choose ({v$!AAv
* Open. You can then make changes to the template in the Source Editor. ^
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*/ O:IU|INq8
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package com.tot.count; f*,jhJ_I
import tot.db.DBUtils; (0 /,R
import java.sql.*; 5z~rl}`v
/** DJVH}w}9_P
* Nj$3Ig"l
* @author x{6KsYEY
*/ ,)TtI~6Q
public class CountControl{ x_pS(O(C
private static long lastExecuteTime=0;//上次更新时间 I<`K;El'
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 P^&%T?Y6z
/** Creates a new instance of CountThread */ cY8XA6
public CountControl() {} |`+kZ-M*
public synchronized void executeUpdate(){ ]v(8i3P84
Connection conn=null; 0x7F~%%2
PreparedStatement ps=null; Cc/h|4
try{ [=7=zV;}4
conn = DBUtils.getConnection(); 2BZYC5jy
conn.setAutoCommit(false); X; I:i%-
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); /2N'SOX
for(int i=0;i<CountCache.list.size();i++){ G0oY`WXOB
CountBean cb=(CountBean)CountCache.list.getFirst(); 4wjy)VD_
CountCache.list.removeFirst(); )h6hN"#V5
ps.setInt(1, cb.getCountId()); g HdNqOy
c
ps.executeUpdate();⑴ UCG8=+t5T
//ps.addBatch();⑵ '3TwrY?-
} H.*:+
//int [] counts = ps.executeBatch();⑶ f!%G{G^`
conn.commit(); AFE6@/'
}catch(Exception e){ i8iv{e2
e.printStackTrace(); _1Iy /T@1
} finally{ KJn@2x6LP
try{ Ir&rTGFN
if(ps!=null) { q,`"Z)97
ps.clearParameters(); FJXYKpY[r
ps.close(); I
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ps=null; @32~#0a
} I,TJV)B
}catch(SQLException e){} ,cZhkXd
DBUtils.closeConnection(conn); l/1u>'
} GKT2x '(e
} Fa<>2KkOr
public long getLast(){ W!vN(1:(
return lastExecuteTime; wNo2$>*
} Q6blX6DWU
public void run(){ -FQ!
long now = System.currentTimeMillis(); Ne<={u%
if ((now - lastExecuteTime) > executeSep) { x\PZ.o
//System.out.print("lastExecuteTime:"+lastExecuteTime); "yaz!?O>
//System.out.print(" now:"+now+"\n"); '!eg9}<
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); !"1}zeve
lastExecuteTime=now; B7PkCS&X
executeUpdate(); \|e>(h!l;
} `_%UK=m
else{ _gU:!:}
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 8Na.H::cZ
} <;Q1u,Mc
} @Wgd(Ezd
} Lzmdy0!'
//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 H#H@AY3Y
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类写好了,下面是在JSP中如下调用。 ?*DM|hzOi
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<% mm}y/dO~}
CountBean cb=new CountBean(); Y-2IAJHS8
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 0lpkG
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CountCache.add(cb); A*+pGQ
out.print(CountCache.list.size()+"<br>"); qt_ocOr
CountControl c=new CountControl(); {
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c.run(); J]&^A$
out.print(CountCache.list.size()+"<br>"); :j(e+A1@
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