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: v@yqTZ
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CountBean.java
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/* P, l
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* CountData.java Vh?vD:|
* |zP~/
* Created on 2007年1月1日, 下午4:44 \#w8~+`Gq
* c7@/<*E+
* To change this template, choose Tools | Options and locate the template under kv2o.q
* the Source Creation and Management node. Right-click the template and choose {fl[BX]kZ
* Open. You can then make changes to the template in the Source Editor. LK*9`dzv=G
*/ `fX\pOk~e
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package com.tot.count; ;R2A>f~
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/** z(^dwMw}
* .6
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* @author NopfL
*/ {cLWum[SY
public class CountBean { Viw,YkC
private String countType; <b_K*]Z
int countId; sg}<()
/** Creates a new instance of CountData */ W1xPK*
public CountBean() {} Lk#)VGk:
public void setCountType(String countTypes){ u #}1
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this.countType=countTypes; e@Ev']
} v*JKLA
public void setCountId(int countIds){ +,ar`:x&a
this.countId=countIds; H\<0{#F
} C\BKdx5;
public String getCountType(){ A=|a!N/
return countType; P(8
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} |P|2E~[r
public int getCountId(){ &Fuk+Cu{
return countId; Zj ` ;IYFG
}
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} OiZ-y7;k^
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CountCache.java ~-lUS0duh
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/* e<`?$tZ3
* CountCache.java >Jn` RsuV
* lnjs{`^
* Created on 2007年1月1日, 下午5:01 "10\y{`v^
* V62lN<M
* To change this template, choose Tools | Options and locate the template under (]I=';\
* the Source Creation and Management node. Right-click the template and choose Wrp+B[{r\
* Open. You can then make changes to the template in the Source Editor. r]D>p&4
*/ }u0&> k|y
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package com.tot.count; &{a#8sbf#c
import java.util.*; gjnEN1T22
/** 'IIa,']H
* D5bi)@G7z
* @author OT|0_d?bD
*/ oSy9Xw
public class CountCache { Q$`uZ
public static LinkedList list=new LinkedList(); 4%_c9nat
/** Creates a new instance of CountCache */ MzKl=G
public CountCache() {} 4A(h'(^7A
public static void add(CountBean cb){ Tw`dLK?
if(cb!=null){ &LB`
list.add(cb); Ic!x y
} 2Y[n
} #X$s5H
} hmuhq:<f
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CountControl.java :ntAU2)H
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/* B]gyj
* CountThread.java W)
* #{?RE?nD
* Created on 2007年1月1日, 下午4:57 NhF"%
* f61vE
* To change this template, choose Tools | Options and locate the template under /.A"HGAk
* the Source Creation and Management node. Right-click the template and choose ZXiJ5BZ
* Open. You can then make changes to the template in the Source Editor. '
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*/ *tR'K#:&g!
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package com.tot.count; >zfx2wh\a
import tot.db.DBUtils; LXrk5>9
import java.sql.*; HP<a'| r
/** KXcRm)
* f qWme:x
* @author l>s@&%;Mg
*/ |90/tNe
public class CountControl{ }>621L3 -
private static long lastExecuteTime=0;//上次更新时间 +N2ILE8[<
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 g@/}SJh/>
/** Creates a new instance of CountThread */ xy&*s\=:
public CountControl() {} 3tUn?;9B
public synchronized void executeUpdate(){ Lrr(7cH,
Connection conn=null; *(]ZdB_2
PreparedStatement ps=null; `}$bJCSF.n
try{ Jx`7W1%T
conn = DBUtils.getConnection(); +eLL)uk
conn.setAutoCommit(false); }jWg&<5+z
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); M5_t#[ [
for(int i=0;i<CountCache.list.size();i++){ i 2uSPV!Tf
CountBean cb=(CountBean)CountCache.list.getFirst(); P;'ZdZ(SLu
CountCache.list.removeFirst(); u:l<NWF^
ps.setInt(1, cb.getCountId()); RwrRN+&s\
ps.executeUpdate();⑴ uocFOlU0n
//ps.addBatch();⑵ )g3c-W=
} fN<Y3^i"
//int [] counts = ps.executeBatch();⑶ N0\<B-8+,>
conn.commit(); b^}U^2S%
}catch(Exception e){ 6^BT32,'
e.printStackTrace(); -G_3B(]`
} finally{ {KEmGHC4R
try{ H%Lln#
if(ps!=null) { m,]9\0GUd
ps.clearParameters(); 9p^gF2?k
ps.close(); ZIh)D[n
ps=null; ^4<&"aoo
} }mUb1b
}catch(SQLException e){} h>!9N
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DBUtils.closeConnection(conn); UYW'pV
} e$`hRZ%
} WW^+X~Y
public long getLast(){ `P:[.hRu
return lastExecuteTime; H<?s[MH[
} -2 8bJ,
public void run(){ "d}ey=$h4
long now = System.currentTimeMillis(); Co=Bq{GY
if ((now - lastExecuteTime) > executeSep) { u'DpZ
//System.out.print("lastExecuteTime:"+lastExecuteTime); 8=0I4\
//System.out.print(" now:"+now+"\n"); :LdPqFXj
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); c"1Z,M;G
lastExecuteTime=now; x1E;dbOZ
executeUpdate(); 0XqxW\8_l
} pNmWBp|ER
else{ Xi\c>eALO
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); =WZ@{z9J
} ?FR-aXx
} e VQ-?DK
} }*qj,8-9
//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 pDvznpQ
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类写好了,下面是在JSP中如下调用。 Y"m(hs$
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<% HGd.meQ
CountBean cb=new CountBean(); 0plX"NU
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); F>X<=YO0
CountCache.add(cb); pe3;pRh'
out.print(CountCache.list.size()+"<br>"); ),xD5~_=q
CountControl c=new CountControl(); &" J;
c.run(); _.BT%4
out.print(CountCache.list.size()+"<br>"); \ptjnwC^O
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