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: n)rSgzI
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CountBean.java Og"\@n
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/* @BqSu|'Du,
* CountData.java A@n//AZM
* 9w$+Qc
* Created on 2007年1月1日, 下午4:44 M;E$ ]Z9
* iuEQ?fp
* To change this template, choose Tools | Options and locate the template under g y1i%
* the Source Creation and Management node. Right-click the template and choose \_|r>vQ
* Open. You can then make changes to the template in the Source Editor. &(A'uX.>pr
*/ J\\o#-H
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package com.tot.count; |3 v+&eVi
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/** ~tqDh(
* 'h;x>r
* @author ]PZ\N~T
*/ qr?RU .W
public class CountBean { C8
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private String countType; 7
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int countId; X=pPkgW
/** Creates a new instance of CountData */ E7|P\^}m(f
public CountBean() {} m"mU:-jk`
public void setCountType(String countTypes){ O-]^_LV`
this.countType=countTypes; .$"69[1H
} \rmge4`4
public void setCountId(int countIds){ xMo'SpVz:
this.countId=countIds; ?4 lDoP{
} Eo_;Nc
public String getCountType(){ %o#|zaK
return countType; u$mp%d8
} (W_U<~`t
public int getCountId(){ &(rR)cG
return countId; Z_[jah
} ?a` $Y>?h
} Iqb|.v LG
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CountCache.java t`vIcCXqyl
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/* d# q8-
* CountCache.java &BQ%df<y\
* ri1:q.:I]
* Created on 2007年1月1日, 下午5:01 TS;?>J-
* [^A>hs*
* To change this template, choose Tools | Options and locate the template under 3Uni{Z]Q)
* the Source Creation and Management node. Right-click the template and choose fnudu0k
* Open. You can then make changes to the template in the Source Editor. Q#*Pjl
*/ $rz'Ybs
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package com.tot.count; =idZvD
import java.util.*; "6o5x&H
/** N1u2=puJY
* ah0
* @author 'A9U[|
*/ y7Y g$)sL
public class CountCache { Y,s@FGI2
public static LinkedList list=new LinkedList(); f7j9'k
/** Creates a new instance of CountCache */ f`8mES'gc8
public CountCache() {} "SN+ ^`
public static void add(CountBean cb){ 5tl uS
if(cb!=null){ HDT-f9%}<4
list.add(cb); D^\2a;[AxA
} a1#
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} ;U$EM+9
} Ems0"e
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CountControl.java y,=TB[d#
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/* O,?aVgY
* CountThread.java -WK
* ]eIV'lP,j/
* Created on 2007年1月1日, 下午4:57 %&b70]S(
* QLe<).S1B2
* To change this template, choose Tools | Options and locate the template under U Zc%XZ`"V
* the Source Creation and Management node. Right-click the template and choose [49Ae2W`
* Open. You can then make changes to the template in the Source Editor. ${)s
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*/ \P7y&`|
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package com.tot.count; Gu@Znh-D
import tot.db.DBUtils; bdkxCt
import java.sql.*; 1PjqXgN5p
/** lF.yQ
* !0
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* @author ,]|*~dd>G
*/ *'nZ|r v
public class CountControl{ c %.vI
private static long lastExecuteTime=0;//上次更新时间 \h 1 T/_4
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 My JG2C#R
/** Creates a new instance of CountThread */ 6pY<,7t0
public CountControl() {} Y'v;!11#
public synchronized void executeUpdate(){ D'3. T{*rH
Connection conn=null; R3Ka^l8R|
PreparedStatement ps=null; c-hhA%@Wq
try{ _=;lt O
conn = DBUtils.getConnection(); P V,AN
conn.setAutoCommit(false); 4m3pF0k
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ,?zOJ,wl
for(int i=0;i<CountCache.list.size();i++){ k?'<f
CountBean cb=(CountBean)CountCache.list.getFirst(); B[nkE+s
CountCache.list.removeFirst(); O\KSPy7YQ
ps.setInt(1, cb.getCountId()); ~7Jj\@68
ps.executeUpdate();⑴ #Ez+1
//ps.addBatch();⑵ f!aE/e\
} Qv>rww]
//int [] counts = ps.executeBatch();⑶ ;(,1pi7|
conn.commit(); ZP^7`q)6
}catch(Exception e){ I`8jJpGA
e.printStackTrace(); <{UjO
} finally{ p$*;>YKO
try{ qmM%MPv
if(ps!=null) { wx%TQ!
ps.clearParameters(); _F9O4Q4
ps.close(); .WT^L2l%
ps=null; kw.IVz<
} mFXkrvOf,
}catch(SQLException e){} K7N.gT*4
DBUtils.closeConnection(conn); [.`%]Z(
} q^k]e{PD
} Ps_q\R
public long getLast(){ Z-B b,8
return lastExecuteTime; K{x FhdW
} +Jv*u8T'
public void run(){ C^ hCT
long now = System.currentTimeMillis(); DR w;.it2
if ((now - lastExecuteTime) > executeSep) { Oe[qfsdW
//System.out.print("lastExecuteTime:"+lastExecuteTime); jJDYl( [
//System.out.print(" now:"+now+"\n"); .&Ok53]b
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); xRU ~hQ
lastExecuteTime=now; 4%L-3Ij
executeUpdate(); KGoHn6jM
} l`A4)8Y@
else{ ,t=12R]>
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ,dO$R.h
} )mb RG9P
} Z2x%
} :u$+lq
//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 Qo;#}%}^^
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类写好了,下面是在JSP中如下调用。 ';0NWFP
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<% 3Ta<7tEM
CountBean cb=new CountBean(); Cq-#|+zr
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Ud8*yB
CountCache.add(cb); ';hTGLq\X
out.print(CountCache.list.size()+"<br>"); oz- k_9%
CountControl c=new CountControl(); ~1yMw.04V
c.run(); tuiQk=[c
out.print(CountCache.list.size()+"<br>"); bn$}U.m$-
%>