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: SY T$3|a
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CountBean.java " #v%36U
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/* 3AeH7g4<
* CountData.java x<>YUw8`
* N}mh}
* Created on 2007年1月1日, 下午4:44 esI'"hVJ
* f3#X0.':
* To change this template, choose Tools | Options and locate the template under v2>Z^
* the Source Creation and Management node. Right-click the template and choose M*`hDdS
* Open. You can then make changes to the template in the Source Editor. CA*~2|
*/ h.}u?{
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package com.tot.count; hKN6 y%
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/** ^Xs]C|=W
* YtYy zX5u7
* @author =
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*/ +zp0" ,2B
public class CountBean { +|&0fGv;d9
private String countType; "dtlME{Bx
int countId; CXAVGO'xw
/** Creates a new instance of CountData */ B}\BeFt'
public CountBean() {} S{:Cu}o
public void setCountType(String countTypes){ !*vBW/
this.countType=countTypes; B^q<2S;
} @GeHWv
public void setCountId(int countIds){ ~kb{K;
this.countId=countIds; bVK$.*,
} doLNz4W
public String getCountType(){ h<NRE0-
return countType; J-XTN"O
} D^?_"wjW
public int getCountId(){ u"Fjw F?
return countId; qm%nIU \*
} s
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} s|2}2<+
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CountCache.java 2f..sNz
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/* 0roCP=;
* CountCache.java 3.),bm
* ~L'nzquF
* Created on 2007年1月1日, 下午5:01 a.,_4;'UE1
* AP w6
* To change this template, choose Tools | Options and locate the template under N`1r;%5
* the Source Creation and Management node. Right-click the template and choose v3-?CQb(
* Open. You can then make changes to the template in the Source Editor. .@k *p >K
*/ ik\S88|
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package com.tot.count; zH=hIVc
import java.util.*; oD0EOT/E
/** y x;h
* Pz`hX$
* @author _9kIRmT{
*/ aD|Yo
public class CountCache { UH20n{_:
public static LinkedList list=new LinkedList(); 5\S&)ZA@
/** Creates a new instance of CountCache */ ps+:</;Z
public CountCache() {}
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public static void add(CountBean cb){ ;BVDt
if(cb!=null){ !<r8~A3!(
list.add(cb); ML=z<u+
} ,sI35I J
} E}$V2ha0zu
} @vAFfYU9<.
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CountControl.java %nQmFIt
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/* VDiOO
* CountThread.java \h#9oPy
* =v0~[E4
* Created on 2007年1月1日, 下午4:57 ^PQM;"
* c&e0OV\m
* To change this template, choose Tools | Options and locate the template under 5^2TfG9
* the Source Creation and Management node. Right-click the template and choose }Vl^EAR
* Open. You can then make changes to the template in the Source Editor. <Uwwux<v
*/ ; )|nkI
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package com.tot.count; hr~.Lj5^W
import tot.db.DBUtils; <kbnu7?a*
import java.sql.*; B5`;MQJ
/** Hirr=a3
* })7K S?
* @author ?O7iK<5N
*/ [q"NU&SX
public class CountControl{ 6t$N78U
private static long lastExecuteTime=0;//上次更新时间 ?*+1~m>
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 {(0Id !
/** Creates a new instance of CountThread */ m1y `v"
public CountControl() {} 8Fx]koP.
public synchronized void executeUpdate(){ r?$&Z^
Connection conn=null; Z@oKz:U
PreparedStatement ps=null; UN(3i(d
try{ 2@*<9-9
conn = DBUtils.getConnection(); ArX]L$D
conn.setAutoCommit(false); -(
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ^'YHJEK
for(int i=0;i<CountCache.list.size();i++){ }VZM,.w
CountBean cb=(CountBean)CountCache.list.getFirst(); #[(gIOrNn8
CountCache.list.removeFirst(); eI?HwP{m
ps.setInt(1, cb.getCountId()); Wl
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ps.executeUpdate();⑴ tvCcyD%w
//ps.addBatch();⑵ ZQ|gt*
} tNB%eb{
//int [] counts = ps.executeBatch();⑶ B
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conn.commit(); q;No"_aAd
}catch(Exception e){ L6xB`E9
e.printStackTrace(); {83C,C-
} finally{ 4v>o%
try{ )*W=GY*
if(ps!=null) { AHWh}~Yi
ps.clearParameters(); TH>,v
ps.close(); $$\V2%v
ps=null; Z,SY
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} L9$&-A9ix
}catch(SQLException e){} IqXBz.p
DBUtils.closeConnection(conn); 1y~L8!:L
} ^8Z@^M&O"
} {=qEBbM
public long getLast(){ (HPz
return lastExecuteTime; /Bh>
} Ej{+U
public void run(){ 4?v$<=#21*
long now = System.currentTimeMillis(); e) ]RA?bF
if ((now - lastExecuteTime) > executeSep) { {wHvE4F2
//System.out.print("lastExecuteTime:"+lastExecuteTime); blUY.{NN3
//System.out.print(" now:"+now+"\n"); m[W/j/$A+x
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ovB=Zm
lastExecuteTime=now; . Jptj
executeUpdate(); %uj[ `
} lS#7xh
else{ 1y 1_6TZ+
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); jmSt?M0.xV
} sbgJw
} <r_3obRC
} 4`$5
_}
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//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 We\KDU\n
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类写好了,下面是在JSP中如下调用。 gji*Wq
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<% "oHp.$+K
CountBean cb=new CountBean(); q)vK`\Y
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ]9#CVv[rq
CountCache.add(cb); 1>hb-OMX
out.print(CountCache.list.size()+"<br>"); CcBQo8!G
CountControl c=new CountControl(); J9NsHr:A[
c.run(); Y$>+U
out.print(CountCache.list.size()+"<br>"); ix:2Z-
%>