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: @Kw&XK e`
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CountBean.java lkC| g%f
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/* JY,oXA6O
* CountData.java FlY"OU*
* 2fNNdxdbT
* Created on 2007年1月1日, 下午4:44 ,?`kYPZ
* ly6dl
* To change this template, choose Tools | Options and locate the template under [Dmf.PUe
* the Source Creation and Management node. Right-click the template and choose n xR\tBv
* Open. You can then make changes to the template in the Source Editor. +q+JOS]L
*/ F&B E+b/#
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package com.tot.count; =
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/** if3z Fh
* O@w_"TJP/z
* @author PWquu`
*/ u9u'5xAO
public class CountBean { 5=}CZYWB
private String countType; (f~}5O<
int countId; Sz]1`%_H/
/** Creates a new instance of CountData */ #r1y|)m`
public CountBean() {} }5}>B *
public void setCountType(String countTypes){ [Z&<# -
this.countType=countTypes; Zq H-]?)
} t:v>W8N53
public void setCountId(int countIds){ 2izBB,# "
this.countId=countIds; 4ElS_u^cP7
} C~'.3Q6
public String getCountType(){ 'pO-h,{TS
return countType; [fELf(;(
} V|*3*W
public int getCountId(){ 8Qj1%Ri:U
return countId; 9[DlJ@T}
} ePxAZg$ `>
} Z&=Oe^
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CountCache.java ;7QG]JX
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/* :bL^S1et
* CountCache.java x}=Q)|)]
* WM4,\$
* Created on 2007年1月1日, 下午5:01 B}K<L\S
* J,s:CBCGL
* To change this template, choose Tools | Options and locate the template under FMzG6nrdBN
* the Source Creation and Management node. Right-click the template and choose 6&L;Sw#Dg
* Open. You can then make changes to the template in the Source Editor. @\>7
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*/ +}:2DXy@
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package com.tot.count; 6E(..fo:"
import java.util.*; _c-(T&u<
/** 0%,?z`UY
* CkNh3'<wg
* @author @W~aoq6
*/ 3II*NANeg
public class CountCache { I :bT"N
public static LinkedList list=new LinkedList(); {XD':2E
/** Creates a new instance of CountCache */ D=Yr/qc?
public CountCache() {} Fq%NY8KNE
public static void add(CountBean cb){ +8"P*z,
if(cb!=null){ qv|}>wU
list.add(cb);
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} Vn\jUEC
} \'|t>|zhp
} n-,mC/4
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CountControl.java $ub0$S/Hu
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/* a=v H:D
* CountThread.java WGyPyG#Fl
* W1ndb:
* Created on 2007年1月1日, 下午4:57 rj?c
* Ug4o2n0sk
* To change this template, choose Tools | Options and locate the template under 1Tev&J
* the Source Creation and Management node. Right-click the template and choose 'MNCJ;A@V
* Open. You can then make changes to the template in the Source Editor. &5G@YQD1e
*/ "D
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package com.tot.count; #.C2_MN>
import tot.db.DBUtils; )5y"T0]
import java.sql.*; <Q`3;ca^
/** nKI?Sc
* \MPbG$ ^
* @author 2]FRIy
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*/ sI09X6)
public class CountControl{ $Zkk14
private static long lastExecuteTime=0;//上次更新时间
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 PzhC *" i}
/** Creates a new instance of CountThread */ ]v?jfy
public CountControl() {} w@n}DCFt
public synchronized void executeUpdate(){ C}DIm&))
Connection conn=null; 1TF S2R n
PreparedStatement ps=null; 7@m+y
try{ _A0X[}^K
conn = DBUtils.getConnection(); nE2?3 S>
conn.setAutoCommit(false); .MID)PY-
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); |ZXz&Xor
for(int i=0;i<CountCache.list.size();i++){ "=JE12=u
CountBean cb=(CountBean)CountCache.list.getFirst(); !\O!Du
CountCache.list.removeFirst(); 5g$>J)Ry
ps.setInt(1, cb.getCountId()); mAJ'>^`^
ps.executeUpdate();⑴ mgM"u94-]
//ps.addBatch();⑵ xO,;4uE
} EWv[Sp
//int [] counts = ps.executeBatch();⑶ |WfL'_?$
conn.commit(); <=w!:
}catch(Exception e){ !4 lN[
e.printStackTrace(); kg,\l9AM
} finally{ u,N<U t
try{ &] xtx>qg<
if(ps!=null) { )r)ZmS5O
ps.clearParameters(); Gvvw:]WgF
ps.close(); <aI}+
ps=null; ^L8:..+:
} `U>2H4P
}catch(SQLException e){} (v?
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DBUtils.closeConnection(conn); v"o@q2f_
} 3preBs#i
} Z)@[N
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public long getLast(){ >ffC?5+
return lastExecuteTime; L=M'QJl9
} U;"J8
public void run(){ fL]jk1.Xv-
long now = System.currentTimeMillis(); ]^i^L
if ((now - lastExecuteTime) > executeSep) { whrDw1>(
//System.out.print("lastExecuteTime:"+lastExecuteTime); BNFYUcVP
//System.out.print(" now:"+now+"\n"); S_RP&+!7
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 'fk6]&-I
lastExecuteTime=now; ?5,I`9
executeUpdate();
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} Q0,eE:
else{ #JXXq%4
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); W
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} &2O~BIRE
} ,ei=w,O
} [nrD4
//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 QXl~a%lB
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类写好了,下面是在JSP中如下调用。 Dk8@x8
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<% 4mpcI
CountBean cb=new CountBean(); G|"m-.9F
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); DZEq(>mn
CountCache.add(cb); #uCfXJ-
out.print(CountCache.list.size()+"<br>"); ;d]vAj
CountControl c=new CountControl(); yF|+oTp
c.run(); sBqOcy
out.print(CountCache.list.size()+"<br>"); VwK7\jV
%>