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: */w7?QOv
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CountBean.java BC! 6O/kr
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/* @QdnjXII*
* CountData.java l4vTU=
* R`#W wx>b
* Created on 2007年1月1日, 下午4:44 2no$+4+z
* {,?ss$L
* To change this template, choose Tools | Options and locate the template under 7?J3ci\
* the Source Creation and Management node. Right-click the template and choose byGn,m
* Open. You can then make changes to the template in the Source Editor. qsI^oBD"
*/ QXVC\@
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package com.tot.count; >{5
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/** &nY;=Hv`WY
* R,t$"bOd
* @author CqFeF?xd8h
*/ Nxk(mec"
public class CountBean { rp's
private String countType; j*400
int countId; $dQIs:
/** Creates a new instance of CountData */ ObG=>WPJa
public CountBean() {} <T+!V-Pj*
public void setCountType(String countTypes){ z.oU4c
this.countType=countTypes; &Z;_TN9[
} T95t"g?p
public void setCountId(int countIds){ W.I\J<=V
this.countId=countIds; ]Gv!M?:
} h3!$r~T!a:
public String getCountType(){ PFrfd_s{>\
return countType; ]$A(9Pn"
} ~#PLAP3-
public int getCountId(){ kn"q:aD
return countId; !'G~k+
} SeEw.;Xw
} n~.*1. P
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CountCache.java < zOi4v0
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/* ;65D
* CountCache.java ?o*I9[Z)
* uw AwWgl
* Created on 2007年1月1日, 下午5:01 G[,Q95`w?<
*
4!.(|h@
* To change this template, choose Tools | Options and locate the template under vLT0ETHg6
* the Source Creation and Management node. Right-click the template and choose $}GTG'*.
* Open. You can then make changes to the template in the Source Editor. Jr;jRe`4c
*/
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package com.tot.count; @7oL#-
import java.util.*; +4))/`DA
/** BU|#e5
* T,%j\0
* @author UUc8*yU)
*/ |7k_N|E
public class CountCache { )e|=mtp
public static LinkedList list=new LinkedList(); ntVS:F
/** Creates a new instance of CountCache */ KNLnn;l
public CountCache() {} &;&ho+qD
public static void add(CountBean cb){ $za8"T*I
if(cb!=null){ eW J`$"z
list.add(cb); E>|: D
} <h-vjz
} 0Hxmm@X2
} 9iUr nG*
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CountControl.java (Qo I<j""
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/* o1cErI&q"
* CountThread.java ).^}AFta
* anMF-x4/*q
* Created on 2007年1月1日, 下午4:57 }|u4 W?H
* *!s;"U
* To change this template, choose Tools | Options and locate the template under W\&8auds
* the Source Creation and Management node. Right-click the template and choose 0j"8@<
* Open. You can then make changes to the template in the Source Editor. /='. 4v
*/ /DQaGq/Ld
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package com.tot.count; jB{4\)
import tot.db.DBUtils; hd),&qoW?
import java.sql.*; gL_Y,A~Q{
/** Bp8'pj;~
* F
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* @author 3RLFp\i"s
*/ %LVm3e9
public class CountControl{ [W%$qZlP
private static long lastExecuteTime=0;//上次更新时间 P9g en6
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 S4=~`$eP
/** Creates a new instance of CountThread */ )OiT{-m
public CountControl() {} b2b^1{@h;v
public synchronized void executeUpdate(){ e/0<[s*#Q
Connection conn=null; x=ul&|^7D
PreparedStatement ps=null; qlL`jWJ
try{ MrZh09y
conn = DBUtils.getConnection(); t2,A@2DU2
conn.setAutoCommit(false); +s- lCz
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); h4q|lA6!k8
for(int i=0;i<CountCache.list.size();i++){ z!l.:F
CountBean cb=(CountBean)CountCache.list.getFirst(); .pvi!NnL-
CountCache.list.removeFirst(); yW$0\E6<r
ps.setInt(1, cb.getCountId()); /"eey(X
ps.executeUpdate();⑴ ZI= %JU(
//ps.addBatch();⑵ {&jb5-*f
} $5Xh,DOg
//int [] counts = ps.executeBatch();⑶ 0TQ$C-%
conn.commit(); 1P~X8=9h
}catch(Exception e){ +=O5YR!{
e.printStackTrace(); zIh['^3.n
} finally{ /YZr~|65
try{ -$\+'
\
if(ps!=null) { -r-k_6QP
ps.clearParameters(); !o:f$6EA~C
ps.close(); ;kY(<{ 2
ps=null; 1v71rf&w
} Q_[ 3`jl
}catch(SQLException e){} O^oWG&Y;v
DBUtils.closeConnection(conn); z^'gx@YD*v
} S:h{2{
} :]\([Q+a
public long getLast(){ eEuvl`&
return lastExecuteTime; <StN%2WQ1
} .&DhN#EN0
public void run(){ +j< p
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long now = System.currentTimeMillis(); ,6-:VIHQ
if ((now - lastExecuteTime) > executeSep) { ;lHr =e7
//System.out.print("lastExecuteTime:"+lastExecuteTime); 0*f)=Q'
//System.out.print(" now:"+now+"\n"); [ucpd
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); '.:z&gSqx0
lastExecuteTime=now; ibj87K
executeUpdate(); wne,e's}
}
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else{ I}1NB3>^
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); <sBbT`
} C{U?0!^
} be.*#[
} e )d`pQ6
//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 U|jSa,}
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类写好了,下面是在JSP中如下调用。 ;lE%M
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<% .%xn&3
CountBean cb=new CountBean(); 9Z4nAc
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); GPN]9
CountCache.add(cb); 6 (]Dh;gC
out.print(CountCache.list.size()+"<br>"); KVclhT<F
CountControl c=new CountControl(); "&Y`+ 0S8
c.run(); {*G9|#[/@
out.print(CountCache.list.size()+"<br>"); Ayxkv)%:@)
%>