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: :BG/]7>|V
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CountBean.java @yPa9Ug(V
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/* v:(_-8:F
* CountData.java
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* 703=.xj
* Created on 2007年1月1日, 下午4:44 i /R8Gb
* O`U&0lKi'
* To change this template, choose Tools | Options and locate the template under Oz!#);v
* the Source Creation and Management node. Right-click the template and choose M0DdrL/
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* Open. You can then make changes to the template in the Source Editor. &mDKpYrB
*/ 0l !%}E
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package com.tot.count; {4Cn/}7Ly^
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/** 6W."hPP
* ~M`QFF
* @author &=5
*/ -8; ,#
public class CountBean { 1tU}}l
private String countType; *_}|EuY
int countId; Fyoy)y*
/** Creates a new instance of CountData */ gE]) z*tqX
public CountBean() {} tpj({
public void setCountType(String countTypes){ T (]
this.countType=countTypes; "knSc0,u
} W+V#z8K
public void setCountId(int countIds){ S/v+7oT
this.countId=countIds; JyWBLi;Z
} fw,ruROqD
public String getCountType(){ M@fUZh
return countType; Dp!3uR']p
} 1[o] u:m9U
public int getCountId(){ ?#ue:O1
return countId; {C Qo}@.7
} He="S3XON
} SC)4u l%
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CountCache.java |rkj$s,
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/* J
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* CountCache.java ,A9pj k'
* Ps5UX6\ .m
* Created on 2007年1月1日, 下午5:01 =wHHR1e
* LivPk`[
* To change this template, choose Tools | Options and locate the template under I
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* the Source Creation and Management node. Right-click the template and choose 6*%3O=*
* Open. You can then make changes to the template in the Source Editor. 8WK%g0gm
*/ <T{2a\i 4f
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package com.tot.count; xcr=AhqM
import java.util.*; q/~U[.C
/** SHS:>V
* _S5\5[^
* @author eW#U<x%P
*/ Y ::\;s
public class CountCache { XbdoTriE
public static LinkedList list=new LinkedList(); |9ro&KA
/** Creates a new instance of CountCache */ 3 G/#OJ
public CountCache() {} J"'2zg1&
public static void add(CountBean cb){ cGiS[-g
if(cb!=null){ I`w1IIY?m
list.add(cb); !4d6wp"
} j%Mz;m4y
} P]gksts9f.
} BFmYbK
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CountControl.java J&%vBg^
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/* 'gd3 w~
* CountThread.java R[ p. )F7
* D"_~Njf
* Created on 2007年1月1日, 下午4:57 I9P<!#q>
* 6r"uDV #0
* To change this template, choose Tools | Options and locate the template under G4->7n N
* the Source Creation and Management node. Right-click the template and choose {?m;DYv
* Open. You can then make changes to the template in the Source Editor. l^4[;%*f#l
*/ 2T/C!^iJ)
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package com.tot.count; z)"7qqA
import tot.db.DBUtils; y]QG;
import java.sql.*; cY?<
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/** QxCZ<|
* CL%?K<um
* @author %\#s@8=2u
*/ J&UFP{)
public class CountControl{ |1J=wp)#
private static long lastExecuteTime=0;//上次更新时间 *%_:[>
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 > ^fY`x,
/** Creates a new instance of CountThread */ }ny,Nl
public CountControl() {} L'=2Uk#.D
public synchronized void executeUpdate(){ ?P4@U9i
Connection conn=null; {n}6
PreparedStatement ps=null; +%(iGI{
try{ c7T9kV8hS
conn = DBUtils.getConnection(); %0T/>:1[E
conn.setAutoCommit(false); $,"{g<*k;
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 3`_jNPV1
for(int i=0;i<CountCache.list.size();i++){ bf2R15|t5`
CountBean cb=(CountBean)CountCache.list.getFirst(); 2Cn^<(F^4I
CountCache.list.removeFirst(); -dbD&8
ps.setInt(1, cb.getCountId()); [tDUR
ps.executeUpdate();⑴ M"[s5=:Lo
//ps.addBatch();⑵ B% !z7AT
} 6$[7t?u
//int [] counts = ps.executeBatch();⑶ Bmuf[-}QW
conn.commit(); d!/@+i
}catch(Exception e){ 3;=nQ{0b
e.printStackTrace(); :gv`)
} finally{ )\_xB_K\
try{ yA_;\\
if(ps!=null) { 9i@AOU
ps.clearParameters(); x][vd^iW
ps.close(); o~!4&
ps=null; |gEA.}
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} R_J=x
}catch(SQLException e){}
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DBUtils.closeConnection(conn); [Z6]$$!#2
} 6dTq&GZ\
} dq~p]h~,H
public long getLast(){ JoQzf~
return lastExecuteTime; q:sDNj)R\
} 6W$ #`N>
public void run(){ "Q9S<O8)
long now = System.currentTimeMillis(); NhQIpzL)
if ((now - lastExecuteTime) > executeSep) { b $x<7l5C
//System.out.print("lastExecuteTime:"+lastExecuteTime); ;AKtbS;H
//System.out.print(" now:"+now+"\n"); B[7|]"L@
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); G3&ES3L
lastExecuteTime=now; EB jiSQw
executeUpdate(); QxvxeK!Y
} ut%t`Y(
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else{ t ]{qizfOB
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); K[)N/Q
} nW+rJ
} :7%JD .;W
} 6"Q/Y[y
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 |Axg}Q|
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类写好了,下面是在JSP中如下调用。 on(P
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<% #EtS9D'd+
CountBean cb=new CountBean(); d_#\^!9
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ] ,Wh]q
CountCache.add(cb); lGqwB,K$z4
out.print(CountCache.list.size()+"<br>"); XPXC7_fV
CountControl c=new CountControl(); `*PVFm>
c.run(); 6u/3"A]'
out.print(CountCache.list.size()+"<br>"); x^_Wfkch]
%>