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: `2`h4[^ [X
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CountBean.java kW&zkE{
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/* r{wf;5d(
* CountData.java B C R]K
* qdo_YPG
* Created on 2007年1月1日, 下午4:44 DTl&V|h$
* BirnCfj/2
* To change this template, choose Tools | Options and locate the template under .&.L@CRH
* the Source Creation and Management node. Right-click the template and choose ;iz3Bf1o
* Open. You can then make changes to the template in the Source Editor. zC`ediyu
*/ 2 ]}e4@{
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package com.tot.count; `HILsU=|
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/** f!G%$?]
* ;ZTh(_7
* @author p1s|JI
*/ Up*6K =Tny
public class CountBean { S+l>@wa)|
private String countType; 6C!TXV'
int countId; jF-0 fK;)*
/** Creates a new instance of CountData */ c3*9{Il^
public CountBean() {} +/rh8?
public void setCountType(String countTypes){ -^t&U]
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this.countType=countTypes;
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} |;R-q8
public void setCountId(int countIds){ lHO.pN`2
this.countId=countIds; jV' tcFr4
} caZEZk#r;
public String getCountType(){ GK&R.R]
return countType; CJ [e^K{
} Ni#y=cb
public int getCountId(){ v1$}JX
return countId; :<uCi\9(
} LG'1^W{a
} :|Bzbn=N2
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CountCache.java ]0g1P-&,U
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/* :AyZe7:(D
* CountCache.java <Ys7`e6eY
* cq9d;~q
* Created on 2007年1月1日, 下午5:01 *oAnG:J+M
* (qDJgf4fgn
* To change this template, choose Tools | Options and locate the template under CFeAKjG
* the Source Creation and Management node. Right-click the template and choose *2Q x69`
* Open. You can then make changes to the template in the Source Editor. *-gmWATC6
*/ $}P>_bq
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package com.tot.count; j&0t!f.Rv
import java.util.*; <<6gsKP
/** L>!MEMqm
* 1wW4bg 5
* @author c}w[T
*/ [yVcH3GcjI
public class CountCache { 'h 7n}
public static LinkedList list=new LinkedList(); cyWDtq
/** Creates a new instance of CountCache */ kS_37-;
public CountCache() {} 3Z74&a$
public static void add(CountBean cb){ ]o`FF="at
if(cb!=null){ ar@ysBy
list.add(cb); 7G_OFD
} ?{>5IjL)en
} Job&qW9W`
} EiWd =jDm
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CountControl.java %Z(lTvqG
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/* >Yfo $S_
* CountThread.java YrTjHIn~w
* *'R2Lo<C
* Created on 2007年1月1日, 下午4:57 }:+P{
* F=yE>[! LB
* To change this template, choose Tools | Options and locate the template under ~PC S_
* the Source Creation and Management node. Right-click the template and choose T7Yg^ -"
* Open. You can then make changes to the template in the Source Editor. E5$uvxCI
*/ ;MjOs&1f0K
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package com.tot.count; ,tuZ_"?M
import tot.db.DBUtils; ; T WYO
import java.sql.*; 1JN/oq;
/** k)JwCt.%
* UbSD?Ew@35
* @author Y'o.`':\~
*/ iD2>-yf
public class CountControl{ hj[sxC>z5
private static long lastExecuteTime=0;//上次更新时间 Xj21:IMR
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 66cPoG
/** Creates a new instance of CountThread */ }fz;La:b
public CountControl() {} *1_A$14l
public synchronized void executeUpdate(){ XPcx"zv\
Connection conn=null;
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PreparedStatement ps=null; ]BBjFs4#
try{ ]yA_N>k2K
conn = DBUtils.getConnection(); <nn!9V\C
conn.setAutoCommit(false); C-ipxL"r
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); =JB1 ]b{|
for(int i=0;i<CountCache.list.size();i++){ 1iE*-K%Q
CountBean cb=(CountBean)CountCache.list.getFirst(); k!m9
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CountCache.list.removeFirst(); K|-RAjE
ps.setInt(1, cb.getCountId()); [E/8E
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ps.executeUpdate();⑴ +K[H!fD
//ps.addBatch();⑵ P4~C0z
} N9cUlrDO
//int [] counts = ps.executeBatch();⑶ D~ %h3HM
conn.commit(); p\M\mK
}catch(Exception e){ c (0Ez@
e.printStackTrace(); 1 *$-.
} finally{ 5[$jrG\!
try{ >]WQ1E[=
if(ps!=null) { 5K?%Eo72!=
ps.clearParameters(); +)TOcxF%
ps.close(); yy|F6Pq3`
ps=null; AN-;*n<'
} `<d{(9:+
}catch(SQLException e){} 6w^Fee`>]
DBUtils.closeConnection(conn); gNzamorv[
} \+sP<'~M
} :KJZo,\
public long getLast(){ N^K@$bs4^
return lastExecuteTime; Hsz).u
} '}
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public void run(){ !Ql&Ls
long now = System.currentTimeMillis(); z c,Q
if ((now - lastExecuteTime) > executeSep) { +W9#^
//System.out.print("lastExecuteTime:"+lastExecuteTime); \~'+TW
//System.out.print(" now:"+now+"\n"); P[C03a!lXg
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); a]_eSU@
lastExecuteTime=now; 5*7
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executeUpdate(); .=4k'99,
} v"G) G)*z
else{ 1]Gp\P}
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); NI?YUhg>
} p=8?hI/bim
} |#-GH$.v
} ~gvw6e*[
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 {F+iL&e)
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类写好了,下面是在JSP中如下调用。 9dD;Z$x&Xk
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<% ;?0r,0l2$
CountBean cb=new CountBean(); En/EQ\T@F
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); /*5lO;!s{
CountCache.add(cb); >R}p*=J
out.print(CountCache.list.size()+"<br>"); 9q!./)
CountControl c=new CountControl(); xBi``x2eY
c.run(); ]pP [0S
out.print(CountCache.list.size()+"<br>"); yjxv D
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