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: a`%`9GD
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CountBean.java
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/* U!r8}@
* CountData.java XK3O,XM
* ^O@eyP
* Created on 2007年1月1日, 下午4:44 B!x#|vGXL
* l+P!I{n
* To change this template, choose Tools | Options and locate the template under b)KEB9w
* the Source Creation and Management node. Right-click the template and choose `MPR-"Z6
* Open. You can then make changes to the template in the Source Editor. k &J;,)V
*/ JfWkg`LqL
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package com.tot.count; xCXsyZ2h
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/** uuwJ-
* c(
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* @author !"qT2<A
*/ [niFJIsc
public class CountBean { }#ta3 x
private String countType; IS(F_< .
int countId; QR"+fzOL
/** Creates a new instance of CountData */ s) U1U6O
public CountBean() {} Qe_{<E
public void setCountType(String countTypes){ >xS({1A}
this.countType=countTypes; "J+L]IC?AD
} JZ-@za6u
public void setCountId(int countIds){ ^-q{:lx
this.countId=countIds; <Qih&P9;>
} (i%bQZt^?
public String getCountType(){ Lr:n
return countType; Ly8=SIZ
} bHRn}K+<}c
public int getCountId(){ xJ{r9~
return countId; G-9i
} 1]=X
} )GVTa4}p
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CountCache.java NN'pBUR
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/* <dP\vLH_
* CountCache.java i;C` .+
* 4PxP*j
* Created on 2007年1月1日, 下午5:01 OXQA(%MK
* }B7Txo,Z
* To change this template, choose Tools | Options and locate the template under ux1(>
* the Source Creation and Management node. Right-click the template and choose h'&<A_C-7
* Open. You can then make changes to the template in the Source Editor. ~%=%5}
*/ W[Q<# Ju
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package com.tot.count; (c)/&~aE
import java.util.*; jXf@JxQ
/** )e3w-es~4
* DmuQE~DV
* @author LJ@(jO{z
*/ +`Q]p "G
public class CountCache { "Tser*i )
public static LinkedList list=new LinkedList(); V':A!
/** Creates a new instance of CountCache */ 3GE;:;8B
public CountCache() {} eEVB
public static void add(CountBean cb){ sS
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if(cb!=null){ d)!'5ZrM
list.add(cb); xS12$ib ~G
} /}E2Rr?{
} |s/N?/qi
} V;SV0~&
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CountControl.java aQL0Sj:,
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/* A+Isk{d
* CountThread.java td%J.&K_*'
* Pd&KAu|<`
* Created on 2007年1月1日, 下午4:57 D`^wj FF
* M&/4SVBF
* To change this template, choose Tools | Options and locate the template under 9yTdbpY
* the Source Creation and Management node. Right-click the template and choose JW0\y+o~
* Open. You can then make changes to the template in the Source Editor. yW'{Z]09
*/ [Lje?M* r
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package com.tot.count; +8Q @R)3
import tot.db.DBUtils; CtN\-E-
import java.sql.*; wg)Bx#>\L:
/** 7Ji'7$
* Xykoq"dbb
* @author eC<RM Q4
*/ JjI1^FRd
public class CountControl{ [6RODp3')
private static long lastExecuteTime=0;//上次更新时间 Rl cL(HM
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 */ ui)mYR[8X
public CountControl() {} Ix_w.f=8
public synchronized void executeUpdate(){ z{ eZsh
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Connection conn=null; jSvq1$U
PreparedStatement ps=null; f:\)!
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try{ $*X?]?
conn = DBUtils.getConnection(); DjK7_'7(L
conn.setAutoCommit(false); ($<&H>j0
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); &1T)'Bn
for(int i=0;i<CountCache.list.size();i++){ 3xz~##
CountBean cb=(CountBean)CountCache.list.getFirst(); ?Ybq]J\q
CountCache.list.removeFirst(); RYvcuA)
ps.setInt(1, cb.getCountId()); %,vq@..^
ps.executeUpdate();⑴
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//ps.addBatch();⑵ T;B FO5G@
} L bJf5xdi
//int [] counts = ps.executeBatch();⑶ 6c^?DLy9B
conn.commit(); e)?}2
}catch(Exception e){ +$L}B-F
e.printStackTrace(); m,kYE9{
} finally{ p+?`ru
try{ Dom]w.W5
if(ps!=null) { ,\
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ps.clearParameters(); KNN{2thy `
ps.close(); 9teP4H}m
ps=null; hfIP
} D`G; C
}catch(SQLException e){} :I&y@@UG
DBUtils.closeConnection(conn); A/a=)su
} 7{M&9| aK
} q M_c-^F
public long getLast(){ Jf=V<
return lastExecuteTime; u8JH~b
} _y6iR&&x
public void run(){ u=L Dfn
long now = System.currentTimeMillis(); \41/84BA
if ((now - lastExecuteTime) > executeSep) { .9ZK@xM&?
//System.out.print("lastExecuteTime:"+lastExecuteTime); 'vtJl
//System.out.print(" now:"+now+"\n"); ygja{W.
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); RTd,bi*
lastExecuteTime=now; -`Z!p
executeUpdate(); 1mtYap4
} 0sw;h.VY
else{ B2$cY;LH
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); sM)1w-
} :!t4.ko
} i^:#*Q-co
} a8)2I~j
//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 ]Zh$9YK
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类写好了,下面是在JSP中如下调用。 FsOJmWZ
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<% 1l)j(,Zd*
CountBean cb=new CountBean(); 7&P70DO
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); yy/'B:g
CountCache.add(cb); Jjj;v2uSK
out.print(CountCache.list.size()+"<br>"); LFi{Q{E)
CountControl c=new CountControl(); <f:(nGj
c.run(); -J6`
out.print(CountCache.list.size()+"<br>"); |PYyhY
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