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: G3Dg B!
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CountBean.java 8%,#TMOg
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/* j0e,>X8
* CountData.java kkjugm{D7
* 2=_$&oT**
* Created on 2007年1月1日, 下午4:44 s\;/U|P_
* }MQ:n8
* To change this template, choose Tools | Options and locate the template under Og 1-LP|X
* the Source Creation and Management node. Right-click the template and choose \U$:/#1Oe
* Open. You can then make changes to the template in the Source Editor. @s1T|}AJ
*/ 6M
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package com.tot.count; |6Q5bV
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/** X)KCk2Ax
* /JS_gr@DK
* @author S9Sgd&a9
*/ .P1WY
public class CountBean { Yj@Sy
private String countType; ^)-[g
int countId; T`E0_ZU;
/** Creates a new instance of CountData */ <MbhBIejr
public CountBean() {} i% 1UUI(W
public void setCountType(String countTypes){ ^sf,mM~D
this.countType=countTypes; !5 }}mf
} _f^6F<!
public void setCountId(int countIds){ lEHx/#qt9
this.countId=countIds; *6?mZ*GYY
} fmixWL7.Zg
public String getCountType(){ jfMkN
return countType; TaRPMKk
} VW\S>=O99
public int getCountId(){ p}QDX*/sSu
return countId;
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} [OCjYC`
} G%I
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CountCache.java TLsF c^X
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/* |`o|;A]
* CountCache.java bo|THS
* 1D'r;`z
* Created on 2007年1月1日, 下午5:01 8{ZTHY-
* @/s|<*
* To change this template, choose Tools | Options and locate the template under m54>}
* the Source Creation and Management node. Right-click the template and choose %>&ex0j]
* Open. You can then make changes to the template in the Source Editor. D"pT?\kO
*/ #+ch
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package com.tot.count; hr];!.Fv
import java.util.*; "OenYiz
/** F1.Xk1y%
* 1'o[9-
* @author [h'u@%N|/
*/ v*!N}1+J
public class CountCache { K) }1;
public static LinkedList list=new LinkedList(); WAxNQfEe
/** Creates a new instance of CountCache */ Dz0D ^(;V
public CountCache() {} _8.TPB]no
public static void add(CountBean cb){ 5!?5S$>
if(cb!=null){ e6taQz@}
list.add(cb); w x]?D%l
} Onq^|r's&
} Ikdj?"+O
} Z+v,o1
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CountControl.java oJ4HvrUO
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/* ,1{qZ(l1
* CountThread.java a]r+np]vTy
* (}39f
* Created on 2007年1月1日, 下午4:57 4J5 zSTw
* J3mLjYy
* To change this template, choose Tools | Options and locate the template under J]U_A/f
* the Source Creation and Management node. Right-click the template and choose vqN/ crJ@
* Open. You can then make changes to the template in the Source Editor. DP@1to@
*/ HFFG4'
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package com.tot.count; *V kaFQZ$,
import tot.db.DBUtils; jkL=JAcf~
import java.sql.*; bJIYe ld
/** q5_zsUR=
* )9nW`d+
* @author I#2$CSJ
*/
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public class CountControl{ 486\a
private static long lastExecuteTime=0;//上次更新时间 b1?^9c#0d
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ?(gha
/** Creates a new instance of CountThread */ g)#?$OhP"
public CountControl() {} dM;\)jm
public synchronized void executeUpdate(){ c
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Connection conn=null; xeFx!$3
PreparedStatement ps=null; !An?<Sv$
try{ fM ID}S
conn = DBUtils.getConnection(); zb{79Os[B
conn.setAutoCommit(false); NfClR HpVc
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?");
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for(int i=0;i<CountCache.list.size();i++){ Aars\
CountBean cb=(CountBean)CountCache.list.getFirst(); {rcN_N%
CountCache.list.removeFirst(); s;I
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ps.setInt(1, cb.getCountId()); "<=4]Z
ps.executeUpdate();⑴ 59zWB,y(P
//ps.addBatch();⑵ !K(
} Da 7(jA+
//int [] counts = ps.executeBatch();⑶ I$.lFQ%(
conn.commit(); Tv"T+!Z
}catch(Exception e){ UDI\o1Rbp
e.printStackTrace(); .T3N"}7[
} finally{ )vO"S
try{ 5@xR`g-
if(ps!=null) { F\r"Y)|b=
ps.clearParameters(); "d)YqQ
ps.close(); K@7%i|H
ps=null; U*~-\jN1pb
} ,
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}catch(SQLException e){} DujVV(+I
DBUtils.closeConnection(conn); 8n5~K.;<
} R:f!ywj%
} <XLaJ;j
public long getLast(){ :"Xnu%1
return lastExecuteTime;
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} Zp/+F(
public void run(){ ]_(hUj._
long now = System.currentTimeMillis(); Sesdhuy.@
if ((now - lastExecuteTime) > executeSep) { @.7/lRr@bp
//System.out.print("lastExecuteTime:"+lastExecuteTime); q7lC}'2fu
//System.out.print(" now:"+now+"\n"); _G'ki.[S7
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 82@^vX
lastExecuteTime=now; ?7Cm+J
executeUpdate(); Zy+ERaF|]
} EK4%4<"
else{ {3
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); _5rKuL
} c~tl0XU1
} ZRf9 'UwS
} |Lg2;P7\
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 &lLk[/b
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类写好了,下面是在JSP中如下调用。 _]*YSeh=
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<% B}TY+@
CountBean cb=new CountBean(); |aLK_]!
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ow \EL
CountCache.add(cb); e$s&B!qJ
out.print(CountCache.list.size()+"<br>"); XnP?hw%
CountControl c=new CountControl(); ^"7-`<J
c.run(); 8p 4[:M@
out.print(CountCache.list.size()+"<br>"); 1*p6UR&
%>