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: m,!SDCq
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CountBean.java ?6&8-zt1?
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/* :S_]!'H
* CountData.java &JqaIJh
* O>1Cx4s5
* Created on 2007年1月1日, 下午4:44 J-,ocO
* 3^~J;U!3
* To change this template, choose Tools | Options and locate the template under \#t)B
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* the Source Creation and Management node. Right-click the template and choose X(MS!R V
* Open. You can then make changes to the template in the Source Editor. '!8-/nlv1
*/ ocJG4#
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package com.tot.count; *wj5( B<y
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/** z]+L=+,,
* S7Ty}?E@
* @author Ec3tfcNhR
*/ ""a$[[ %WC
public class CountBean {
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private String countType; H(K
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int countId; [K\b"^=<
/** Creates a new instance of CountData */ 2wIJ;rh
public CountBean() {} !e~[U-
public void setCountType(String countTypes){ C`ky=
this.countType=countTypes; >20dK
} `(0B09~7
public void setCountId(int countIds){ z<vh8dNl
this.countId=countIds; 4,c6VCw3+
} Z%B6J>;u M
public String getCountType(){ X(*O$B{
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return countType; bNVeL$'
} w,FPL&{
public int getCountId(){ &4S2fWx
return countId; L}Y.xi
} jJNCNH*0
} y"q>}5
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CountCache.java jxkjPf?
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/* %}VH5s9\
* CountCache.java D4[t^G;J
* {ptHk<K:)
* Created on 2007年1月1日, 下午5:01 @e
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* >VkBQM-%
* To change this template, choose Tools | Options and locate the template under 3}8o 9
* the Source Creation and Management node. Right-click the template and choose 0~^RHb.NA8
* Open. You can then make changes to the template in the Source Editor. mQ"uG?NE
*/ pLtw|S'4
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package com.tot.count; e@W+ehx"
import java.util.*; m)Kg6/MV.
/** x'I!f? / &
* </`\3t
* @author ?}4,s7PR
*/ kt978qfk
public class CountCache { @
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public static LinkedList list=new LinkedList(); ngl +`|u
/** Creates a new instance of CountCache */ d9M[]{
public CountCache() {} c:Nm!+5_(
public static void add(CountBean cb){ 8$
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if(cb!=null){ h7UNmwj
list.add(cb); ~EPVu
} x~!|F5JbM
} %ERcFI]G
} ;: 2U}p^-
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CountControl.java j/*1zu8Y
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/* nJ2x;';lA
* CountThread.java P U/<7P*
* 96(Mu% l
* Created on 2007年1月1日, 下午4:57 6^[4.D
* |2u=3#Jp
* To change this template, choose Tools | Options and locate the template under ?!U[~Gq
* the Source Creation and Management node. Right-click the template and choose @I`^\oJ
* Open. You can then make changes to the template in the Source Editor. hDW!pnj1
*/ |j`73@6
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package com.tot.count; VIP7j(#t_g
import tot.db.DBUtils; =\WF +r]V
import java.sql.*; 1^}I?PbqV
/** ^U*y*l$
* *(?Wzanh
* @author 3uqhYT;
*/ Ww2@!ng
public class CountControl{ _xp8*2~-
private static long lastExecuteTime=0;//上次更新时间 Mz(Vf1pi%
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ?1SsF>|
/** Creates a new instance of CountThread */ rm,`M
public CountControl() {} W8^m-B&
public synchronized void executeUpdate(){ WR"D7{>tw
Connection conn=null; YOD.y!.zq7
PreparedStatement ps=null; TQF+aP8[L
try{ GBbnR:hM
conn = DBUtils.getConnection(); #4msBax4
conn.setAutoCommit(false); x?+w8jSR
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 'j6O2=1
for(int i=0;i<CountCache.list.size();i++){ mLxgvp
CountBean cb=(CountBean)CountCache.list.getFirst(); (?na|yd
CountCache.list.removeFirst(); }|kFHodo
ps.setInt(1, cb.getCountId()); k||t<&`Ze
ps.executeUpdate();⑴ S'jg#*$
//ps.addBatch();⑵ 3N2dV6u
} ;/j2(O^
//int [] counts = ps.executeBatch();⑶ >CqzC8JF
conn.commit(); E[]5Od5#
}catch(Exception e){ No'?8 +i
e.printStackTrace(); ecghY=%
} finally{ Hsf::K x
try{ _5jT}I<k
if(ps!=null) { E^axLp>(I
ps.clearParameters(); 8Y?M:^f~
ps.close(); >1Z"5F7=
ps=null; 'rcqy1-&
} v3I^81
}catch(SQLException e){} ,yYcjs!=o
DBUtils.closeConnection(conn); 4N,mcV
} EO&Q
} $oK&k}Q
public long getLast(){ *9aJZWf>V
return lastExecuteTime; $v|W2k
} o8bd L<
public void run(){ ^}_Ka //k
long now = System.currentTimeMillis(); WTJ 0Q0U
if ((now - lastExecuteTime) > executeSep) { 1`&`y%c?B
//System.out.print("lastExecuteTime:"+lastExecuteTime); gsk?
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//System.out.print(" now:"+now+"\n"); -Uwxmy +
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ;.A}c)b
lastExecuteTime=now; 7Q}pKq]P
executeUpdate(); M3pE$KT0x
} AI-*5[w#A
else{ <xOX+D
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); k {*QU(
} ysW})#7X
} >NRppPqL
} ky2 bj}"p9
//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 FlBhCZ|^
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类写好了,下面是在JSP中如下调用。 Z7;V}[wie
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<% zw/AZLS
CountBean cb=new CountBean(); zR" cj
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ANM#Kx+
CountCache.add(cb); Z[oF4 z
out.print(CountCache.list.size()+"<br>"); D0D=;k
CountControl c=new CountControl(); 2r,
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c.run(); 1qRquY
out.print(CountCache.list.size()+"<br>"); qb>41j9_t
%>