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: cjN)3L{
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CountBean.java b\0>uU
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/* QQW}.>N
* CountData.java `/[5/%
* , ~
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* Created on 2007年1月1日, 下午4:44 '!^7 *@z
* inU5eronuj
* To change this template, choose Tools | Options and locate the template under Z
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* the Source Creation and Management node. Right-click the template and choose a[nSUlT&
* Open. You can then make changes to the template in the Source Editor. ~Y`ys[Z m
*/ EK4%4<"
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package com.tot.count; hM]Z T5;<
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/** zH~P-MqC
* _]*YSeh=
* @author =W7-;&
*/ ;\w3IAa|V
public class CountBean { ~+1mH
private String countType; nx%A s
int countId; 8p 4[:M@
/** Creates a new instance of CountData */ FXo.f<U
public CountBean() {} ta{24{?M\
public void setCountType(String countTypes){ {Lal5E4-
this.countType=countTypes; DyqqY$ vH(
} ^>an4UJt
public void setCountId(int countIds){ R*pPUw\yn
this.countId=countIds; +#,J`fV%
} -ZE YzZqY
public String getCountType(){
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return countType; MDytA0M
} iYB c4'X
public int getCountId(){ CtMqE+j^
return countId; 02Vfg42
} ]D;*2Lw4&
} zI[<uvxzW`
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CountCache.java 1av#u:jy~>
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/* Evj%$7H1L1
* CountCache.java
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* lt-3OcC
* Created on 2007年1月1日, 下午5:01 N4;g"k b
* ?jz\[0)s
* To change this template, choose Tools | Options and locate the template under ]0T*#U/P
* the Source Creation and Management node. Right-click the template and choose <eEIR
* Open. You can then make changes to the template in the Source Editor. HlX~a:.7
*/ P Ptmh. }e
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* b0(
package com.tot.count; tRI<K
import java.util.*; H<!q@E
;
/** Iq%<E:+GL
* `^/8dIya
* @author />E
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*/ vWmp?m
public class CountCache { /1Gmga5
public static LinkedList list=new LinkedList(); {Y5@SIyE
/** Creates a new instance of CountCache */ dBA&NW07
public CountCache() {} U;i CH
public static void add(CountBean cb){ Q4 &P\V
if(cb!=null){ >"IG\//I
list.add(cb); %J-:%i
} &Ih }"
} )SP"V~^Wn
} t0fgG/f'
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CountControl.java &I=o1F2B)
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/* <D:q4t
* CountThread.java <w}^Z}fpk&
* ;bG?R0a
* Created on 2007年1月1日, 下午4:57 ?i_/f} .K
* l'4 <^q
* To change this template, choose Tools | Options and locate the template under JAKs [@:
* the Source Creation and Management node. Right-click the template and choose [xY-=-T*4
* Open. You can then make changes to the template in the Source Editor. (M|DNDM'd
*/ evZP*N~G
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package com.tot.count; E4o{Z+C
import tot.db.DBUtils; 5Q%)|(U'
import java.sql.*; }l+_KA
/** An#[
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* ]r!|@AWrQ\
* @author H(K!{k
*/ qF^P\cD
public class CountControl{ *
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private static long lastExecuteTime=0;//上次更新时间 nLAwo3
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 o=94H7@
/** Creates a new instance of CountThread */ c}$>UhLe
public CountControl() {} >0:3CpO*
public synchronized void executeUpdate(){ 837:;<T
Connection conn=null; sF)$<[w
PreparedStatement ps=null; GQ?FUFuIoW
try{ y|BHSc3
conn = DBUtils.getConnection(); QqF*SaO>
conn.setAutoCommit(false); Ep;?%o ,G
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); F$4=7Njv
for(int i=0;i<CountCache.list.size();i++){ B>'J5bZsw
CountBean cb=(CountBean)CountCache.list.getFirst(); ~)$R'=
CountCache.list.removeFirst(); gktlwiCZ
ps.setInt(1, cb.getCountId()); }8l+Jd3"
ps.executeUpdate();⑴ x&u@!# d]
//ps.addBatch();⑵ rZ.=Lq
} A #SO}c
//int [] counts = ps.executeBatch();⑶ 27[e0 j
conn.commit(); ]3|h6KWq
}catch(Exception e){ [7x;H
e.printStackTrace(); 3ONW u
} finally{
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try{ G+sB/l"
if(ps!=null) { w=-{njMz6&
ps.clearParameters(); 1$# r)S[*
ps.close(); i)cG
ps=null; tMU10=d
} (?uK
}catch(SQLException e){} Qu<HeSA_
DBUtils.closeConnection(conn); s$9ow<oi]
} y#Nrq9r:
} [Z'4YXS
public long getLast(){ H.n|zGQTB
return lastExecuteTime; .'+JA:3R
} 3- d"-'k
public void run(){ wU]8hkl?
long now = System.currentTimeMillis(); @DM NLsQ
if ((now - lastExecuteTime) > executeSep) { s#0m
//System.out.print("lastExecuteTime:"+lastExecuteTime); N8r+Q%ov
//System.out.print(" now:"+now+"\n"); [KO\!u|?YS
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); R. ryy
lastExecuteTime=now; 2"xhFxoD7
executeUpdate(); 7~MWp4.
} WV|9d}5
else{ b[n6L5P5m2
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); W^:g_
} *"/BD=INv}
} LWM& k#i
} {[H#lX 4
//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 ^CDh! )
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类写好了,下面是在JSP中如下调用。 $:DL+E-}
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<% aC'#H8e|j
CountBean cb=new CountBean(); OH+2)X
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); %HZ!s
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CountCache.add(cb); [.G~5%974
out.print(CountCache.list.size()+"<br>"); l_q1h]/
CountControl c=new CountControl(); 6l>016 x
c.run(); #zd}xla0]
out.print(CountCache.list.size()+"<br>"); p_3VFKq>0
%>