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\>y&'J-
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CountBean.java &h8+-
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/* qm@c[b
* CountData.java hDjsGB|Fz
* eW0:&*.vMj
* Created on 2007年1月1日, 下午4:44 2m/1:5
* X7Cou6r
* To change this template, choose Tools | Options and locate the template under 7Ja^d-F7
* the Source Creation and Management node. Right-click the template and choose @X
* Open. You can then make changes to the template in the Source Editor. at
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*/ wC..LdSR
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package com.tot.count; ]'DtuT?Z
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/** =HYMX"s
* bXC;6xZV
* @author }us%G&A2u
*/ _dIv{L!
public class CountBean { %~ZOQ%c1
private String countType; S'B7C>i`#N
int countId; {(7C=)8):
/** Creates a new instance of CountData */ wa@X^]D8
public CountBean() {} `61VP-r
public void setCountType(String countTypes){ n[AJ'A{
this.countType=countTypes; ZsNUT4
} \Vr(P>
public void setCountId(int countIds){ L}lc=\
this.countId=countIds; <b{Le{QJ*
} }m\
public String getCountType(){ a:H}c9$%
return countType;
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} T[~ak"M
public int getCountId(){ xAon:58m{
return countId; *`=V"nXw$|
}
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} z^ KrR
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CountCache.java c3g\*)Jz"F
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/* 4$1sBY/
* CountCache.java [[LCEw
* xH; 4lw
* Created on 2007年1月1日, 下午5:01 ){L`hQ*=w
* v|CRiwx
* To change this template, choose Tools | Options and locate the template under UTHGjE
* the Source Creation and Management node. Right-click the template and choose %~}9#0h)
* Open. You can then make changes to the template in the Source Editor. f\2'/g}6a
*/ '~<D[](/F
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package com.tot.count; "a>%tsl$K
import java.util.*; QR\qGhQ~
/** =Q[5U9
* Go+f0aig
* @author r#d~($[93
*/ +Y'(,J
public class CountCache { +c+#InsY
public static LinkedList list=new LinkedList(); ~~&8I!r e
/** Creates a new instance of CountCache */ "Do9gW
public CountCache() {} CdC&y}u
public static void add(CountBean cb){ ,d&~#W]
if(cb!=null){ RVlC8uJ;P
list.add(cb); MJ4+|riB
} CP["N(fF
} A
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} p@YU7_sF^!
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CountControl.java _u]Wr%D@
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/* 3'
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* CountThread.java YDz:;Sp\
* 87r#;ND
* Created on 2007年1月1日, 下午4:57 nhiCV>@y
* %dhnp9'
* To change this template, choose Tools | Options and locate the template under X3<<f`X
* the Source Creation and Management node. Right-click the template and choose Ycn*aR2
* Open. You can then make changes to the template in the Source Editor. n;/yo~RR
*/ S^a")U4
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package com.tot.count; s{'r'`z.
import tot.db.DBUtils; sMs 0*B-[
import java.sql.*; #92MI#|n9
/** <vhlT#p
* m7cp0+Peo
* @author D}&U3?g=
*/ tb"UGa
public class CountControl{ eM*@}3
private static long lastExecuteTime=0;//上次更新时间 u01x}Ff~6
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Bd31>
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/** Creates a new instance of CountThread */ doW_vu
public CountControl() {} #q6jE
public synchronized void executeUpdate(){ _ ?xORzO
Connection conn=null; B14z<x}Q
PreparedStatement ps=null; R*'rg-d
try{ !%_}Rv!JT
conn = DBUtils.getConnection(); !J3g, p*
conn.setAutoCommit(false); sJw#^l
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); CM!bD\5
for(int i=0;i<CountCache.list.size();i++){
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CountBean cb=(CountBean)CountCache.list.getFirst(); E}b"
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CountCache.list.removeFirst(); 3.xsCcmP
ps.setInt(1, cb.getCountId()); qVx4 t"%L>
ps.executeUpdate();⑴ 9]xOuCb
//ps.addBatch();⑵ tF
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} wHEt;rc(
//int [] counts = ps.executeBatch();⑶ ![0\m2~iv
conn.commit(); D0.7an6
}catch(Exception e){ ^R!
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e.printStackTrace(); |Q@4F&k
} finally{ z^ rf;
try{ =NQDxt}
if(ps!=null) { @9~6+BZOq
ps.clearParameters(); VK[^v;
ps.close(); F$^RM3
ps=null; es6!p 7p?
} }[ld=9p(
}catch(SQLException e){} {M )Y6\v
DBUtils.closeConnection(conn); sV%<U-X
} 5.q2<a :
} |p-, B>p!
public long getLast(){ to|O]h2*U2
return lastExecuteTime; -2{NI.-Xd
} 9!NL<}]{
public void run(){ %7xx"$P:R
long now = System.currentTimeMillis(); ;w a-\Z
if ((now - lastExecuteTime) > executeSep) { l#Ipo5=
//System.out.print("lastExecuteTime:"+lastExecuteTime); xVfAlN37(
//System.out.print(" now:"+now+"\n"); )R(kXz=M
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); wzwEYZN(q
lastExecuteTime=now; W_Z%CBjcT
executeUpdate(); ^mv F%"g
} [U5[;BNRD
else{ !9_HZ(W&
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); HQCxO?
} g=XvqD<
} yT.h[yv"w
} -Wd2FD^x
//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 &CpxD."8x
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类写好了,下面是在JSP中如下调用。 Hbn%CdDk1
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<% M%92^;|`
CountBean cb=new CountBean(); #^|y0:
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); NjrF":'Y
CountCache.add(cb); &)zNu
out.print(CountCache.list.size()+"<br>"); 3CL/9C>
CountControl c=new CountControl(); O3/][\
c.run(); A<fKO <d
out.print(CountCache.list.size()+"<br>"); ;4>YPH
%>