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: dRC
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CountBean.java
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/* n@1;5)&k~
* CountData.java q-?
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* PH!^ww6
* Created on 2007年1月1日, 下午4:44 e8E*Urtz
* fyHFfPEE
* To change this template, choose Tools | Options and locate the template under }enS'Fpf`
* the Source Creation and Management node. Right-click the template and choose /w[B,_ZKTk
* Open. You can then make changes to the template in the Source Editor. "&9L
*/ xbUL./uj
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package com.tot.count; (_2Iu%F
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/** _T\/kJ)Q\
* Q5K<ECoPk
* @author /xS4>@hn
*/ t?&@bs5~g
public class CountBean { Xgb ~ED]
private String countType; d;:H#F+ (
int countId; 7tZvz `\
/** Creates a new instance of CountData */ XHN*'@
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public CountBean() {} $!Qv f
public void setCountType(String countTypes){ [B0]%!hFw
this.countType=countTypes; mE>v (JY
} >{/As][
public void setCountId(int countIds){ 6I8A[
this.countId=countIds; ,q_'l?Pn
} _U
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public String getCountType(){ 1UHlA8w7Q
return countType; S{uKm1a
} &Y`V A
public int getCountId(){ 40?xu#"
return countId; <q}w, XU
} PJ$C$G
} Uj/m
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CountCache.java 27"M]17)
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/* GF^)](xY+
* CountCache.java `S)*(s?T
* sLHUQ(S!
* Created on 2007年1月1日, 下午5:01 (Ci{fY6`
* !<EQVqj6
* To change this template, choose Tools | Options and locate the template under pwIu;:O!?
* the Source Creation and Management node. Right-click the template and choose LvM;ZfAEv
* Open. You can then make changes to the template in the Source Editor. 0aWy!d
*/ BI|BfO%F$j
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package com.tot.count; dGc<{sQzB
import java.util.*; nuvRjd^N
/** j Z6]G{
* +KcD Y1[
* @author {.HFB:<!}
*/ ,)svSzR
public class CountCache { ]QqT.z%B
public static LinkedList list=new LinkedList(); __mnz``/Y
/** Creates a new instance of CountCache */ dRhsnT+KX
public CountCache() {} j]6c_r3
public static void add(CountBean cb){ 178u4$# b
if(cb!=null){ :6T8\W
list.add(cb); DQ08dP((v
}
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CountControl.java X:/Y^Xu
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/* G+k~k/D 6
* CountThread.java fR^aFT
* :nLhg$wMs
* Created on 2007年1月1日, 下午4:57 s{Wj&.)M
* 1woBw>g
* To change this template, choose Tools | Options and locate the template under
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* the Source Creation and Management node. Right-click the template and choose 9im<J'
* Open. You can then make changes to the template in the Source Editor. /c4@QbB
*/ n[f<]4<
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package com.tot.count; }#bX{?f
import tot.db.DBUtils; H)5V \
import java.sql.*; MJ%gF=$X
/** {>]7xTpwZ
* "d3qUk
* @author ;ND)h pD+
*/ w(6(Fze
public class CountControl{ 0hCrEM!8
private static long lastExecuteTime=0;//上次更新时间 xRiWg/Z~
private static long executeSep=60000;//定义更新间隔时间,单位毫秒
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/** Creates a new instance of CountThread */ Z\1wEGP7{
public CountControl() {} um5n3=K
public synchronized void executeUpdate(){ h ycdk1SN
Connection conn=null; QPZ|C{Ce
PreparedStatement ps=null; Vmb `%k20'
try{ naaww
conn = DBUtils.getConnection(); y5!fbmf
conn.setAutoCommit(false); Xlp $xp"
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); O9/7?"l"
for(int i=0;i<CountCache.list.size();i++){ ^6?)EM#
CountBean cb=(CountBean)CountCache.list.getFirst(); J|gRG0O9Ya
CountCache.list.removeFirst(); sfUKH;xC
ps.setInt(1, cb.getCountId()); >P_/a,O8
ps.executeUpdate();⑴ I `I+7~t
//ps.addBatch();⑵ $TK<~3`
} ? 3'O
//int [] counts = ps.executeBatch();⑶ "I
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conn.commit(); ;5.S"
}catch(Exception e){ M~SbIk<#a<
e.printStackTrace(); wVMR&R<t
} finally{ @TqqF:c7
try{ ]hC6PKJU
if(ps!=null) { qVe&nXo
ps.clearParameters(); MEled:i
ps.close(); >I&'Rj&Mc
ps=null; R>CIEL
} 84|oqwZO
}catch(SQLException e){} \[CPI`yQe
DBUtils.closeConnection(conn); C\RJ){dk
} 2g`<*u*
} Kc,=J?Ob
public long getLast(){ i p"LoCE
return lastExecuteTime; {g@?\
} wusj;v4C4M
public void run(){ QGkMT+A
long now = System.currentTimeMillis(); PQJI~u9te}
if ((now - lastExecuteTime) > executeSep) { ='U>P(
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//System.out.print("lastExecuteTime:"+lastExecuteTime); na)-'
//System.out.print(" now:"+now+"\n"); G Ch]5\
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); -&UP[Mq
lastExecuteTime=now; by0@G"AE+
executeUpdate(); kbcqUE
} mR|;}u;d
else{ %j7HIxZh
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); jVxX! V
} 9% wVE]
} UFOUkS
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} \YN(rD-
//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 6_vhBYLf
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类写好了,下面是在JSP中如下调用。 s ~Xa=_+D
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<% piPx8jT`F
CountBean cb=new CountBean(); r}%2;!T
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); hP$v,"$
CountCache.add(cb); xoQ;fVNp
out.print(CountCache.list.size()+"<br>"); Pr_$%x9D
CountControl c=new CountControl(); a|u&N:v7B
c.run(); &'{?Y;A
out.print(CountCache.list.size()+"<br>"); }r _d{nhi
%>