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: m`|Z1CT
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CountBean.java ~gf$ L9
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/* &P;x<7h$t?
* CountData.java :1iw_GhJf
* ]kPco4
* Created on 2007年1月1日, 下午4:44 I.>LG
* I'gnw~
* To change this template, choose Tools | Options and locate the template under i0P+,U
* the Source Creation and Management node. Right-click the template and choose -}(W=r\
* Open. You can then make changes to the template in the Source Editor. U;31}'b
*/ >dM'UpN@
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package com.tot.count; dx~Wm1
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/** mH?hzxa+
* }LRAe3N%8
* @author Rm
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*/ 0\mzGfd
public class CountBean { (Cq-8**dY
private String countType; L=$P
int countId; m} V,+E
/** Creates a new instance of CountData */ Zwcb5\Q
public CountBean() {} " n\!y~:
public void setCountType(String countTypes){ t!k 0n&P
this.countType=countTypes; B[$e;h*Aw[
} 5Ql6?UHD
public void setCountId(int countIds){ pxN'E;P-
this.countId=countIds; c*h5lM'n6
} ^\!^#rO
public String getCountType(){ b&ADj8cKC
return countType; r}991O<
} 41.+3VP
public int getCountId(){ Wj3H
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return countId; ;8A_-$
} QhZ%<zN
} <D=%55
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CountCache.java WlY%f}ln
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/* B)(A#&nrb
* CountCache.java 5!Guf?i
* n"pADTaB
* Created on 2007年1月1日, 下午5:01 wjl?@K
* eI[z%j[Y*
* To change this template, choose Tools | Options and locate the template under y0Tb/&xN
* the Source Creation and Management node. Right-click the template and choose V=c&QPP
* Open. You can then make changes to the template in the Source Editor. DJbj@ 2W[
*/ h$k(|/+
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package com.tot.count; |h'ugx1iY
import java.util.*; U3Q'ZT
/** .`iq+i~
* Uq&|iB#mF
* @author K)k!`du!6
*/ 2q#$?qs_b
public class CountCache { vb%\q sf
public static LinkedList list=new LinkedList(); t;*'p
/** Creates a new instance of CountCache */ VTF),e!
public CountCache() {} [-%oO
public static void add(CountBean cb){ [Nq4<NK
if(cb!=null){ )&w\9}B:
list.add(cb); ,Pl[SMt!
} {C3bCVQ]o
} %=|I;kI?
} <sPB|5Ak
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CountControl.java 3:C *'@
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/* M--6oR7
* CountThread.java E1>3 [3
* ZpwB"%e$
* Created on 2007年1月1日, 下午4:57 R &-bA3w$
* { u;ntDr
* To change this template, choose Tools | Options and locate the template under >s{[d$
* the Source Creation and Management node. Right-click the template and choose ve>8vw2
* Open. You can then make changes to the template in the Source Editor. rsIjpPa
*/ FY
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package com.tot.count; X`22Hf4ct
import tot.db.DBUtils; DZ EA*E >
import java.sql.*; 'al-C;Z
/** u!F3Rh8D
* YX~H!6l
* @author `T mIrc
*/ 6I>W(_T
public class CountControl{ s*S@}l
private static long lastExecuteTime=0;//上次更新时间 M+ H$Jjcs
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 2\7]EW
/** Creates a new instance of CountThread */ "=Ziy4V
public CountControl() {} alq>|,\x
public synchronized void executeUpdate(){ 2Ay2
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Connection conn=null; q-uYfXZ{j
PreparedStatement ps=null; =7$YBCuF
try{ a
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conn = DBUtils.getConnection(); `]fY9ZDKs
conn.setAutoCommit(false); {Xl
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); (g
for(int i=0;i<CountCache.list.size();i++){ =n;ileGm+^
CountBean cb=(CountBean)CountCache.list.getFirst(); <yIJ$nBx
CountCache.list.removeFirst(); 4YdmG.CU
ps.setInt(1, cb.getCountId()); `OBDx ^6F
ps.executeUpdate();⑴ )[/+j"F
//ps.addBatch();⑵ ;Yi ;2ttW
} &<L+;k~P%
//int [] counts = ps.executeBatch();⑶ vuD tEz
conn.commit(); e#08,wgW
}catch(Exception e){ VNPuO U=
e.printStackTrace(); !QYqRH~5
} finally{ (=7e~'DC
try{ @O4m-Oosi
if(ps!=null) { ~(FyGB}
ps.clearParameters(); k8w8I$QEM
ps.close(); /*st,P$"
ps=null; rJR"[TTJ
} Mj[v _&N
}catch(SQLException e){} {y :/9
DBUtils.closeConnection(conn); lS}5bcjR=k
} "4I`.$F%O(
} QHA<7Wg
public long getLast(){ _sw,Y!x%dF
return lastExecuteTime; /\C9FGS
} B<+}_3.
public void run(){ *-gS u
long now = System.currentTimeMillis(); 1!,lI?j,
if ((now - lastExecuteTime) > executeSep) { O Y /QA
//System.out.print("lastExecuteTime:"+lastExecuteTime); hyFq>XFo
//System.out.print(" now:"+now+"\n"); ^uC1\!Q1
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); V/<dHOfR\
lastExecuteTime=now; Spt[b.4m F
executeUpdate(); =]&R6P>
} MiAXbo#\
else{ pT:CvJ
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ~cQP4
kBD]
} 8K7zh.E
} <HI5xB_
} n SmYa7
//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 0}-&v+
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类写好了,下面是在JSP中如下调用。 \snbU'lfP
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<% "pQM$3n(
CountBean cb=new CountBean(); 'BcxKqC
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); &YDb/{|CIC
CountCache.add(cb); 4f'WF5S/}8
out.print(CountCache.list.size()+"<br>"); 9T`xW]Zf
CountControl c=new CountControl(); .0r5=
c.run(); V! a|rTU6
out.print(CountCache.list.size()+"<br>"); wnN@aO6g*
%>