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: :s_o'8z7L
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CountBean.java co,0@.i
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/* jNxTy UU
* CountData.java TqJ @l
* r QzdHA
* Created on 2007年1月1日, 下午4:44 !v2/sq$G
* }/J"/ T
* To change this template, choose Tools | Options and locate the template under RrxbsG1HP
* the Source Creation and Management node. Right-click the template and choose ,|c;x1|O
* Open. You can then make changes to the template in the Source Editor. qz-
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*/ MXW1:
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package com.tot.count; 7bYwh8
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/** nHRsr x
* cPcH
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* @author i>S@C@~
*/ /@
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public class CountBean { >!5RY8+
private String countType; @Yt394gA%\
int countId; I{w(`[Nxw*
/** Creates a new instance of CountData */ Zf>:h
public CountBean() {} r!b>!
public void setCountType(String countTypes){ QE/kR!r
this.countType=countTypes;
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} \asn^V@"zz
public void setCountId(int countIds){ 2lfEJw($
this.countId=countIds; ;):;H?WS|A
} `Ku:%~$/
public String getCountType(){ <e! TF@
return countType; KxErWP%
} >}wFePl
public int getCountId(){ 9O &]!ga
return countId; p7AsNqEp
} ]ovtH.y
} 9'(^Coq
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CountCache.java =m<b+@?T
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/* pIR_2Eq
* CountCache.java .hckZx /
* Z>UM gu3c
* Created on 2007年1月1日, 下午5:01 (6/aHSXI
* C_3,|Zq?|
* To change this template, choose Tools | Options and locate the template under ,#N}Ni:
* the Source Creation and Management node. Right-click the template and choose ~NE`Ad.G
* Open. You can then make changes to the template in the Source Editor. 6
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*/ @ddCVxd
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package com.tot.count; K!AA4!eUzM
import java.util.*; h}|.#!C3
/** uj)vh
* Iep_,o.Sk
* @author u~,hTY(%
*/ 0B[~j7EGO
public class CountCache { G5|nt#>
public static LinkedList list=new LinkedList(); v~x`a0
/** Creates a new instance of CountCache */ F,as>X#
public CountCache() {} cGs&Kn;h
public static void add(CountBean cb){ pzt<[;
if(cb!=null){ _x|R`1`
list.add(cb); >'#vC]@
} E<D^j^T
} N[-$*F,:_
} J:)ml
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CountControl.java 3w>1R>7
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/* +9]t]Vrw
* CountThread.java i{9.bpp/
* zk1]?
* Created on 2007年1月1日, 下午4:57 ZUj1vf6I
* kbvF
9#
* To change this template, choose Tools | Options and locate the template under -+i7T^@|
* the Source Creation and Management node. Right-click the template and choose %<+Ku11
* Open. You can then make changes to the template in the Source Editor. oR%cG"y
*/ L{1[:a)']B
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package com.tot.count; PDH|=meXM
import tot.db.DBUtils; 4h?@D_{k
import java.sql.*; daCkjDGl\
/** [T9]q8"
* 3-AOB3](
* @author H6 ,bpjY
*/ Za?BpV~
public class CountControl{ >bI\pJ
private static long lastExecuteTime=0;//上次更新时间 `*0VN(gf'
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 UdcV<#
/** Creates a new instance of CountThread */ P}=n^*8(I
public CountControl() {} <}.!G>X
public synchronized void executeUpdate(){ 45BpZ~-
Connection conn=null; 3xRn
PreparedStatement ps=null; vz3olHX
try{ >`[+24e
conn = DBUtils.getConnection(); g0QYBrp
conn.setAutoCommit(false); toU<InN
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ;FuST
for(int i=0;i<CountCache.list.size();i++){ *T}c{/
CountBean cb=(CountBean)CountCache.list.getFirst(); Myn51pczl
CountCache.list.removeFirst(); F(/Ka@
ps.setInt(1, cb.getCountId()); X]2x0
ps.executeUpdate();⑴ S&&QU#
//ps.addBatch();⑵ kZ6:=l
} iZ/iMDfC
//int [] counts = ps.executeBatch();⑶ #y"LFoJn
conn.commit(); UCj<FN `
}catch(Exception e){ YuHXm3[
e.printStackTrace(); `|&0j4(Pg
} finally{ @o1#J`rv
try{ v=dK2FaY
if(ps!=null) { gw">xt5
ps.clearParameters(); NBBR>3nt
ps.close(); ;jQ^8S
ps=null; 4M0p:Ey '
} fGA#0/_`
}catch(SQLException e){} '"c`[L7Wn
DBUtils.closeConnection(conn); x
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} _V8;dv8
} 5zZQt+Ip
public long getLast(){ )Pc>+}D
return lastExecuteTime; 2[1t
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} ]
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public void run(){ p1.3)=T
long now = System.currentTimeMillis(); }G^'y8U
if ((now - lastExecuteTime) > executeSep) { m$hkmD|
//System.out.print("lastExecuteTime:"+lastExecuteTime); '~7zeZ'
//System.out.print(" now:"+now+"\n"); ?I+$KjE+
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 6Hy_7\$(-
lastExecuteTime=now; L?M
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executeUpdate(); $Fi1Bv)
} b?!S$S xz
else{ S{)K_x
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); <gFisc/#r
} ?|Z~mE
} UxF9Ko( ]d
} sV0NDM0
//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 $*:$-
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类写好了,下面是在JSP中如下调用。 Lr
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<% .!+7|us8l\
CountBean cb=new CountBean(); ,h/l-#KS
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 8}AWU
CountCache.add(cb); ~>_UTI
out.print(CountCache.list.size()+"<br>"); Brd9"M|d
CountControl c=new CountControl(); / $s(OFbi#
c.run(); WCk. K
out.print(CountCache.list.size()+"<br>"); C1l'<
%>