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: $_;e>*+x
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CountBean.java HMGB>
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/* TQ@d~GR
* CountData.java 3ec`Wa
* +A8j@d#:
* Created on 2007年1月1日, 下午4:44 9~\kF5Q"
* vH[47Cv G5
* To change this template, choose Tools | Options and locate the template under kOL'|GgK
* the Source Creation and Management node. Right-click the template and choose J([s5:.[
* Open. You can then make changes to the template in the Source Editor. J^#:qk
*/ ,m3e?j@;r
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package com.tot.count; NAC_pM&B
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/** A^ \.Z4=d"
* Kv&g5&N,
* @author r=uN9ro
*/ feM6K!fL`
public class CountBean { hZXXBp
private String countType; SLL3v,P(7
int countId; #6v27:XK
/** Creates a new instance of CountData */ H6*^Ga
public CountBean() {} BaI $S>/Q
public void setCountType(String countTypes){ o G*5f
this.countType=countTypes; XN=67f$Hw
} HSUI${<
public void setCountId(int countIds){ en S}A*Io
this.countId=countIds; s8"8y`u
} {P%9
public String getCountType(){ u7%D6W~m0
return countType; IY'=DePd
} `>Tu|3%\
public int getCountId(){ hg.#DxRi{
return countId; Qj{8?lew
} |~`as(@Ih
} +d}E&=p_
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CountCache.java O|IG_RL]
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/* $
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* CountCache.java ^ 2GHe<Y
* 2,2Z`X
* Created on 2007年1月1日, 下午5:01 t.8 GT&p
* 2"P99$"
* To change this template, choose Tools | Options and locate the template under 6k{2 +P
* the Source Creation and Management node. Right-click the template and choose ,_aM`%q?Fj
* Open. You can then make changes to the template in the Source Editor. <#=N
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*/ 1d"Z>k:mn
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package com.tot.count; EC2+`HJ"
import java.util.*; xJ^>pg8
/** S1Z2_V
* kE>0M9EdH
* @author o./.Q9e7
*/ +y7;81ND
public class CountCache { Q)m4_+,d
public static LinkedList list=new LinkedList(); 5Wyz=+?m|
/** Creates a new instance of CountCache */ qf@q]wtar
public CountCache() {} 8KB>6[H!wE
public static void add(CountBean cb){ sQ6}\
if(cb!=null){ <~}7Mxn%x@
list.add(cb); M#"524Nz
} 4a0:2 kIKa
} [${
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} MObt,[^W
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CountControl.java ]V %.I_
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/* e0@6Pd
* CountThread.java n55Pv3}C
* v(*C%.M)
* Created on 2007年1月1日, 下午4:57 9CA^B2u
* f.aSKQD
* To change this template, choose Tools | Options and locate the template under q{s(.Uq$&
* the Source Creation and Management node. Right-click the template and choose 0q>P~]Ow
* Open. You can then make changes to the template in the Source Editor. D']ZlB'K
*/ bwVPtu`
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package com.tot.count; Qy<[7
import tot.db.DBUtils; gmIqT
f
import java.sql.*; /27JevE
/** 2LrJ>Mi
* ~$'\L
* @author \!(
*/ 'O5'i\uz
public class CountControl{
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private static long lastExecuteTime=0;//上次更新时间 }kw/W#)J
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 4h5g'!9-g
/** Creates a new instance of CountThread */ b'VV'+|
public CountControl() {} {o5V7*P;_
public synchronized void executeUpdate(){ hjaT^(Y
Connection conn=null; .s#;s'>g
PreparedStatement ps=null; FMkOo2{
try{ >fH=DOz$&
conn = DBUtils.getConnection(); D:k3"
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conn.setAutoCommit(false); `D9]*c
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); :4~g;2oag
for(int i=0;i<CountCache.list.size();i++){ ^TMJ8`e
CountBean cb=(CountBean)CountCache.list.getFirst(); `:P
CountCache.list.removeFirst(); [SJ6@q
ps.setInt(1, cb.getCountId()); R@Gq)P9?
ps.executeUpdate();⑴ &]
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//ps.addBatch();⑵ u0P)7~%
} .sQ=;w/ZA
//int [] counts = ps.executeBatch();⑶ R[49(>7H4
conn.commit(); d,8mY/S>w
}catch(Exception e){ e[sK@jX6
e.printStackTrace(); |
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} finally{ bSVlk`
try{ +?p.?I
if(ps!=null) { 4w#``UY)'
ps.clearParameters(); 3 ?Y|
ps.close(); XU+<?%u}z
ps=null; vG \a1H
} I^oE4o
}catch(SQLException e){} jV(6>BAI_
DBUtils.closeConnection(conn); C3G)'\yL
} {R/C0-Q^^
} ix#epuN
public long getLast(){ nXjPx@
return lastExecuteTime; gN)c
} ;raN
public void run(){ =6aS&B(SN
long now = System.currentTimeMillis(); P"<U6zM\sP
if ((now - lastExecuteTime) > executeSep) { )DYI
.
//System.out.print("lastExecuteTime:"+lastExecuteTime); "t^URp3
//System.out.print(" now:"+now+"\n"); hJzxbr
<
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); <hwy*uBrD
lastExecuteTime=now; a0Ik`8^`
executeUpdate(); Fg Lrb#
} _fZZ_0\Q
else{ WK="J6K5
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); w.&1%X(k
} '#(v=|J
} )K'N(w
} aZEn6*0B
//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 zG e'*Qei
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类写好了,下面是在JSP中如下调用。 !QDQ_
#
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<% S(\9T1DVe
CountBean cb=new CountBean(); C/(M"j M
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); }du XC[ 6
CountCache.add(cb); wH~kTU2br
out.print(CountCache.list.size()+"<br>"); OgF+OS
CountControl c=new CountControl(); 0%)i<a!_Z
c.run(); Yq(G;mjM
out.print(CountCache.list.size()+"<br>"); /m!Cc/Hv
%>