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: .4.zy]I
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CountBean.java nj
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/* 2hu;N
* CountData.java :DQHb"(
* (x#4BI}L9)
* Created on 2007年1月1日, 下午4:44 mp!6MO Q
* A1Rt
* To change this template, choose Tools | Options and locate the template under [o\O^d
* the Source Creation and Management node. Right-click the template and choose Hz*!c#
* Open. You can then make changes to the template in the Source Editor. 1R1J/Z*V/
*/ S9-K
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package com.tot.count; |o=eS&)
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/** G^j/8e
* bL{wCo-Y
* @author ^;Ap-2Ww
*/ YVqhX]/
public class CountBean { }B}?q V
private String countType; Hg]Q.SeJ(
int countId; nv@$'uQRp
/** Creates a new instance of CountData */ >8o RO
public CountBean() {} LlX 7g_!
public void setCountType(String countTypes){ vM|?;QM
this.countType=countTypes; n%W~+
} EKq9m=Ua@o
public void setCountId(int countIds){ VO[s:e9L
this.countId=countIds; !:a
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} @dD70T
public String getCountType(){ (fb&5=Wzw
return countType; EZE/~$`3
} Y <Ta2H
public int getCountId(){ zeNvg/LI^
return countId; B,,f$h!
}
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} q_']i6
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CountCache.java 4LJUO5(y@
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/* :C_\.pA
* CountCache.java ~z%K9YcyU
* rh?!f(_@
* Created on 2007年1月1日, 下午5:01 >jRz4%
* L:%;
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* To change this template, choose Tools | Options and locate the template under L]9uY
* the Source Creation and Management node. Right-click the template and choose q2Ax-#
* Open. You can then make changes to the template in the Source Editor. OGrp{s
*/ D8C@x`
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package com.tot.count; UYD(++
import java.util.*; )9{?C4NQ
/** Xc"S"a^\%
* fp|b@
* @author qun#z$
*/ Iy6"2$%a
public class CountCache { xaAJ>0IM
public static LinkedList list=new LinkedList(); k2_ "
/** Creates a new instance of CountCache */ 4:y;<8+j\
public CountCache() {} q --NLm@;
public static void add(CountBean cb){ 6rF[eb
if(cb!=null){ WojZ[j>
list.add(cb); O>lF{yO0`
} 7Ha
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} (zCas}YAKI
} .~4%TsBaY
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CountControl.java yf2U-s
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/* u&9|9+"N
* CountThread.java HhH[p E
* ;vc$;54K
* Created on 2007年1月1日, 下午4:57 ,AhQA
* K%1'zSAyK
* To change this template, choose Tools | Options and locate the template under 2_
<
* the Source Creation and Management node. Right-click the template and choose )PVX)2P_C
* Open. You can then make changes to the template in the Source Editor. 593D/^}D
*/ %o.{h
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package com.tot.count; {~.h;'m
import tot.db.DBUtils; i$?i1z*c}
import java.sql.*; sX^m1v~N|
/** RYZh"1S;k
* /<\>j+SC
* @author w*e O9k
*/ K%Vl:2#F
public class CountControl{ ICTl{|i ]
private static long lastExecuteTime=0;//上次更新时间 ]<WKi=
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ZUVk~X3
/** Creates a new instance of CountThread */ L*6Tz'Qp
public CountControl() {} W+ Z]
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public synchronized void executeUpdate(){ .fk!~8b[Q+
Connection conn=null; Ha)eeE$
PreparedStatement ps=null; bu1O<*
try{ MR:Co4(
conn = DBUtils.getConnection(); 9mIq9rQ|*
conn.setAutoCommit(false); w3a`G|
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); w[qWr@
for(int i=0;i<CountCache.list.size();i++){ r%}wPN(?D
CountBean cb=(CountBean)CountCache.list.getFirst(); #5-0R7\d7
CountCache.list.removeFirst(); .\7R/cP}{A
ps.setInt(1, cb.getCountId()); ~raRIh=
ps.executeUpdate();⑴ lCr
//ps.addBatch();⑵ ;HlVU
} JVD#wwic
//int [] counts = ps.executeBatch();⑶ B-
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conn.commit(); AA:Ch?
}catch(Exception e){ 6!
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e.printStackTrace(); _S7GkpoK
} finally{ <*<7p{x
try{ '
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if(ps!=null) { Q|rrbx b
ps.clearParameters(); DI'wZySS^
ps.close(); NmthvKhH
ps=null; N J9H=
} a*0gd-e0@
}catch(SQLException e){} m
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DBUtils.closeConnection(conn); wLAGe'GX
} Nc()$Nl8
} MoIVval/
public long getLast(){ RAxAy{
return lastExecuteTime; CTv-$7#
} [R iCa
public void run(){ B8NOPbT
long now = System.currentTimeMillis(); #G:~6^A
if ((now - lastExecuteTime) > executeSep) { 2VyLt=mdh
//System.out.print("lastExecuteTime:"+lastExecuteTime); bEfxu;Su3
//System.out.print(" now:"+now+"\n"); UxzZr%>s
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); oIdMDp^$
lastExecuteTime=now; 1tHTjEG4^3
executeUpdate(); 8QV+DDZx
} -8X*(7
else{ c!AGKc
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); gmB?L0UV
} `PnB<rf:*1
} 3rhH0{
} /[`bPKr
//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 i|0H {q
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类写好了,下面是在JSP中如下调用。 CS"2Sd 1`
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<% d\WnuQR[
CountBean cb=new CountBean(); eVL'Ao&Ho
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); M]oO1GM
CountCache.add(cb); 3de<H=H'
out.print(CountCache.list.size()+"<br>"); `{s:lf
CountControl c=new CountControl(); t5G@M&d4Eo
c.run(); ;>{BK,
out.print(CountCache.list.size()+"<br>"); /!rH DcR
%>