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: ~[J&n-bJU
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CountBean.java VW7
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/* e[3rz%'Q
* CountData.java x*)@:W!
* ~(TS>ck@
* Created on 2007年1月1日, 下午4:44 w85PRruW
* -PHVM=:
* To change this template, choose Tools | Options and locate the template under B:YUb{CJ
* the Source Creation and Management node. Right-click the template and choose lC/4CPKtV
* Open. You can then make changes to the template in the Source Editor. :Kc}R)6
*/ q><E?
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package com.tot.count; k)2L<Lmn
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/** oSb,)k@
* +4k Bd<0Y
* @author FFT h}>>
*/ k+^-;=u6<
public class CountBean { t3TnqA
private String countType; a0Y/,S*K
int countId; ! H)D@,@ &
/** Creates a new instance of CountData */ E(i<3U"4h[
public CountBean() {} N'L3Oa\%
public void setCountType(String countTypes){ K-$gTV
this.countType=countTypes; `+~@VZ3m
} D`;Q?fC
public void setCountId(int countIds){ XYbc1+C
this.countId=countIds; _)q,:g~fu
} d7xd"
public String getCountType(){ qTA@0fL
return countType; Ea%}VZ&[
} =K<8X!xUW
public int getCountId(){ J$)lYSNE
return countId; qb+vptg@I
} AiXxn'&i
} P^-tGo!
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CountCache.java 7o$4ov;T
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/* r)jj]$0
* CountCache.java _rQM[{Bkg
* @_&@M~ u
* Created on 2007年1月1日, 下午5:01 w5I
+5/I
* )'{:4MX
* To change this template, choose Tools | Options and locate the template under NX?J
* the Source Creation and Management node. Right-click the template and choose ';buS -|6
* Open. You can then make changes to the template in the Source Editor. s=lkK/ [
*/ $]/a/!d
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package com.tot.count; lFT_J?G$'
import java.util.*; +zpmy3Q
/** sjLI^#a
* Vi~9[&.E\!
* @author em@\S
*/ j HT2|VGb*
public class CountCache { neGCMKtzlJ
public static LinkedList list=new LinkedList(); %DAF26t
/** Creates a new instance of CountCache */ 9}`A_KzFx
public CountCache() {} 1uTbN
public static void add(CountBean cb){ #D"fCVIS
if(cb!=null){ _"8\k7S*
list.add(cb); kve{CO*
} b {e nD
} 8=^o2&
} MtAD&+3$
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CountControl.java Z:|2PQ4
*
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/* CVsc#=w0
* CountThread.java @P:
* W{\){fr6O
* Created on 2007年1月1日, 下午4:57 dKcHj<'E/
* }SHF
* To change this template, choose Tools | Options and locate the template under ET4 C/nb
* the Source Creation and Management node. Right-click the template and choose a_5 `9B L
* Open. You can then make changes to the template in the Source Editor. XJ;kyEx3=O
*/ euHX7
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package com.tot.count; OiAi{ 71
import tot.db.DBUtils; w$*t.Q*
import java.sql.*; =R)9_D6I
/** WY%LeC!t
* .$>?2|gRv
* @author gP*:>[lR
*/ 2RDos#
public class CountControl{ IAbK]kA
private static long lastExecuteTime=0;//上次更新时间 #`5 M(
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 \[&~.B
/** Creates a new instance of CountThread */ >a98H4
public CountControl() {} P)~PrTa%
public synchronized void executeUpdate(){ :0Nd4hA
Connection conn=null; \M/XM6:UG4
PreparedStatement ps=null; vv,OBL~{
try{ 0(VQwGC[
conn = DBUtils.getConnection(); *7hr3x
conn.setAutoCommit(false); UA3%I8gu_
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); fG O.wb
for(int i=0;i<CountCache.list.size();i++){ X%!#Ic]Q
CountBean cb=(CountBean)CountCache.list.getFirst(); @9|sNS
CountCache.list.removeFirst(); i*j[j~2>C;
ps.setInt(1, cb.getCountId()); vB, X)
ps.executeUpdate();⑴ hM2^[8
//ps.addBatch();⑵ 'j];tO6GfC
} )+[IR
//int [] counts = ps.executeBatch();⑶ |MvCEp
conn.commit();
xz YvD{>
}catch(Exception e){ >G<AyS&z*
e.printStackTrace(); .L%_#A
} finally{ DUiqt09`~
try{ fL4F
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if(ps!=null) { =8 d`qS"
ps.clearParameters(); ):C4"2l3
ps.close(); }' `2C$
ps=null; A(#hyb#
} F(/^??<5
}catch(SQLException e){} Owalt4}C
DBUtils.closeConnection(conn); +vfk+6
} 4RsV\Y{FN
} &;7\/m*W1
public long getLast(){ C(C4R+U
return lastExecuteTime; z%t>z9hU
} +u*WUw!%
public void run(){ bU1UNm`{C
long now = System.currentTimeMillis(); ?lCKZm.,(-
if ((now - lastExecuteTime) > executeSep) { (
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//System.out.print("lastExecuteTime:"+lastExecuteTime); pU)wxv[~
//System.out.print(" now:"+now+"\n"); o<loc Z
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); UT$G?D";M
lastExecuteTime=now; }Tn]cL{]C
executeUpdate(); E,5jY
} X""<5s'0
else{ r: n^U#
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 6R5) &L
} !<}<HR^)
} S|Wv1H>
} kc `Q-
N}
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 nn$,|/
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类写好了,下面是在JSP中如下调用。 ^r73(8{)
v#:#w.]-Y
<% swuW6p
CountBean cb=new CountBean(); OUn,URI
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); R@t?!`f!+
CountCache.add(cb); y!fV+S,
out.print(CountCache.list.size()+"<br>"); {PGNPxUbe
CountControl c=new CountControl(); e4Ol:V
c.run(); R`Hyg4?
out.print(CountCache.list.size()+"<br>"); -uN5DJSW
%>