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: +4qU>
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CountBean.java zj|WZ=1*Wp
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/* '+Xlw
* CountData.java l= }~v
* PdeBDFWD
* Created on 2007年1月1日, 下午4:44 Dyg?F
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* 831JwSR
* To change this template, choose Tools | Options and locate the template under ~1kXUWq3
* the Source Creation and Management node. Right-click the template and choose k2 Q
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* Open. You can then make changes to the template in the Source Editor. D@oCP =m<
*/ 0?0Jz
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package com.tot.count; `ln1$
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/** ?rYT4vi
* b)#Oc,
* @author ;GGK`V
*/ ^U[D4UM
public class CountBean { :dI\z]Y(
private String countType; CC^E_j T
int countId; @b#^ -
/** Creates a new instance of CountData */ k1
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public CountBean() {} t*XN_=E$f
public void setCountType(String countTypes){ FFKGd/:!
this.countType=countTypes; \ I`p|&vG
} 3)=c]@N0
public void setCountId(int countIds){ u3 0s_\
this.countId=countIds; 28.~iw
} xiblPF_n3
public String getCountType(){ .TJEUK
return countType; ,u9M<B<F
} V5f9]D
public int getCountId(){ XT>.`, sv
return countId; lB91An
} R&f^+0%f
} E:`v+S_h
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CountCache.java {a(&J6$VE
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/* Dnf*7)X
* CountCache.java LOy0hN-$b
* ZraT3
* Created on 2007年1月1日, 下午5:01 rjx6Djo>
* SQ*k =4*r
* To change this template, choose Tools | Options and locate the template under 4LH[4Yj?`
* the Source Creation and Management node. Right-click the template and choose e4>"92hX
* Open. You can then make changes to the template in the Source Editor. *J|(jdu7
*/ <[:o !$
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package com.tot.count; 2d>hi32I
import java.util.*; tCG76LH
/** v"& pQ
* SMH<'F7i
* @author 2{Vcb
*/ M$4[)6Y
public class CountCache { BQH}6ueZ
public static LinkedList list=new LinkedList(); wIB`%V
/** Creates a new instance of CountCache */ I
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public CountCache() {} b89a)k>^g
public static void add(CountBean cb){ $j}OB6^I
if(cb!=null){ 7Z ;?b0W
list.add(cb); )rW&c-'
} :r#)z4d5
} U6E\AvbRn
} 0|&\'{
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CountControl.java jHXwOJq
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/* o2z]dTJ}o
* CountThread.java [u}(57DS
* 'H5M|c$s
* Created on 2007年1月1日, 下午4:57 WY^W.1X
* Q\ /uKQ
* To change this template, choose Tools | Options and locate the template under M-)RQ-h
* the Source Creation and Management node. Right-click the template and choose X$%4$
* Open. You can then make changes to the template in the Source Editor. c;0Vs,DUmG
*/ j>Iaq"
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package com.tot.count; qy)_wM
import tot.db.DBUtils; BrRL7xX
import java.sql.*; ;9o;r)9~
/** [/s&K{+c
* g_5Q A)4x
* @author gz2\H}
*/ 5DOBsf8Jo
public class CountControl{ i%e7LJ@5AW
private static long lastExecuteTime=0;//上次更新时间 nOx4<Wk&
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ~'37`)]z
/** Creates a new instance of CountThread */ =K'cM=WM6
public CountControl() {} QrO\jAZ{Ag
public synchronized void executeUpdate(){ {7 TlN.(
Connection conn=null; -7J| l
PreparedStatement ps=null; ^7zu<lX
try{ 1I@8A>2^OX
conn = DBUtils.getConnection(); N7E$G{TT
conn.setAutoCommit(false); xGTP;NT_H
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); V%$/#sza
for(int i=0;i<CountCache.list.size();i++){ 4DZ-bt'
CountBean cb=(CountBean)CountCache.list.getFirst(); ifN64`AhRX
CountCache.list.removeFirst(); T~QJO0
ps.setInt(1, cb.getCountId()); g&/T*L
ps.executeUpdate();⑴ aQ:5d3m0
//ps.addBatch();⑵ y.KO :P?5{
} rZ8`sIWQt
//int [] counts = ps.executeBatch();⑶ *m?/O}R
conn.commit(); bfo["
}catch(Exception e){ PkI:*\R
e.printStackTrace(); Q.K,%(^;a
} finally{ &0f5:M{P
try{ vfVj=DYj
if(ps!=null) { 9z6XF]A
ps.clearParameters(); y;/VB,4V
ps.close(); dOa%9[
ps=null; jKt7M>P
} Eke5Nb
}catch(SQLException e){} 6Gf?m;
DBUtils.closeConnection(conn); 2eMTxwt*S
} MEB it
} RX/hz|
public long getLast(){ vWAL^?HUP
return lastExecuteTime; I`NjqyTW
} #g6.Glz3
public void run(){ f^W;A"+
long now = System.currentTimeMillis(); 9(QJT}qC
if ((now - lastExecuteTime) > executeSep) { j?'GZ d"B
//System.out.print("lastExecuteTime:"+lastExecuteTime); 98^V4maR:
//System.out.print(" now:"+now+"\n"); t!RiU ZAo
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 5\z`-)
lastExecuteTime=now; SdD6 ~LS
executeUpdate(); wI(M^8F_Mf
} Xh56T^,2
else{ *}P~P$q%
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Gz.|]:1
} H%D$(W
} 21"1NJzP
} F'0O2KQ
//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 t5 G9!Nn
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类写好了,下面是在JSP中如下调用。 j]`PSl+w
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<% O%bEB g
CountBean cb=new CountBean(); vN;mPd~g
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); EFz&N\2
CountCache.add(cb); eA<0$Gs,h
out.print(CountCache.list.size()+"<br>"); !KUi\yQ1
CountControl c=new CountControl(); ~@}Bi@*
c.run(); eio4k-
out.print(CountCache.list.size()+"<br>"); %7|9sQ:
%>